Annual report pursuant to Section 13 and 15(d)

Debt (Details)

v3.19.3.a.u2
Debt (Details)
$ in Millions
 3 Months Ended 9 Months Ended 12 Months Ended
Mar. 04, 2019
USD ($)
Dec. 13, 2018
USD ($)
Oct. 12, 2018
USD ($)
Dec. 31, 2018
USD ($)
Sep. 28, 2019
USD ($)
Dec. 31, 2019
USD ($)
Dec. 31, 2018
USD ($)
Dec. 31, 2017
USD ($)
Jul. 03, 2019
USD ($)
Aug. 09, 2018
USD ($)
Jul. 13, 2018
USD ($)
Jun. 28, 2018
USD ($)
Long-term Debt [Abstract]                        
Total Long-Term Debt Including Current Maturities       $ 1,220.8   $ 1,109.3 $ 1,220.8          
Current Maturities of Long-term Debt       (41.3)   (41.3) (41.3)          
Long-Term Debt, Net       1,179.5   1,068.0 1,179.5          
Debt Issuance Costs, Net       15.4   8.1 15.4          
Maturities of Long-term Debt [Abstract]                        
2019           41.3            
2020           42.0            
2021           35.7            
2022           305.8            
2023           0.4            
Thereafter           684.1            
Total Long-Term Debt Including Current Maturities       1,220.8   1,109.3 1,220.8          
Line of Credit Facility [Abstract]                        
Line of Credit Facility, Maximum Borrowing Capacity           400.0            
Letters of Credit Outstanding, Amount           13.1            
Debt Instrument, Face Amount                   $ 800.0    
Remaining Payment for Debt Extinguishment       115.0                
Payment for Debt Extinguishment or Debt Prepayment Cost           $ 185.0            
Minimum [Member]                        
Line of Credit Facility [Abstract]                        
Debt Instrument, Covenant, Interest Coverage Ratio           3.00            
Maximum [Member]                        
Line of Credit Facility [Abstract]                        
Debt Instrument, Covenant, Leverage Ratio           3.50            
6.375% Senior Notes due 2049 [Member]                        
Long-term Debt [Abstract]                        
Total Long-Term Debt Including Current Maturities       0.0   $ 222.2 0.0          
Interest Rate           6.375%            
Due date           2049            
Discount on Long-term Debt       0.0   $ 0.0 0.0          
Debt Issuance Costs, Net       0.0   7.8 0.0          
Maturities of Long-term Debt [Abstract]                        
Total Long-Term Debt Including Current Maturities       0.0   222.2 0.0          
Senior Notes Due 2021 [Member]                        
Long-term Debt [Abstract]                        
Total Long-Term Debt Including Current Maturities [1]       147.3   $ 0.0 147.3          
Interest Rate           4.625%            
Due date           2021            
Discount on Long-term Debt       0.0   $ 0.0 0.0          
Debt Issuance Costs, Net       1.0   0.0 1.0          
Maturities of Long-term Debt [Abstract]                        
Total Long-Term Debt Including Current Maturities [1]       147.3   $ 0.0 147.3          
Line of Credit Facility [Abstract]                        
Debt Instrument, Redemption Price, Triggering Event           101.00%            
Term Loan Due 2021 [Member]                        
Long-term Debt [Abstract]                        
Total Long-Term Debt Including Current Maturities [2]       149.5   $ 0.0 149.5          
Interest Rate           3.85%            
Due date           2021            
Discount on Long-term Debt       0.0   $ 0.0 0.0          
Debt Issuance Costs, Net       0.5   0.0 0.5          
Maturities of Long-term Debt [Abstract]                        
Total Long-Term Debt Including Current Maturities [2]       149.5   0.0 149.5          
Debentures Due 2023 [Member]                        
Long-term Debt [Abstract]                        
Total Long-Term Debt Including Current Maturities [1]       102.6   $ 105.2 102.6          
Interest Rate           7.375%            
Due date           2023            
Discount on Long-term Debt       0.2   $ 0.1 0.2          
Debt Issuance Costs, Net       0.2   0.2 0.2          
Maturities of Long-term Debt [Abstract]                        
Total Long-Term Debt Including Current Maturities [1]       102.6   105.2 102.6          
Loan With Fond Du Lac County Economic Development Corporation Due 2021 [Member]                        
Long-term Debt [Abstract]                        
Total Long-Term Debt Including Current Maturities       15.3   $ 11.1 15.3          
Interest Rate           2.00%            
Due date           2021            
Discount on Long-term Debt       3.0   $ 2.3 3.0          
Debt Issuance Costs, Net       0.1   0.0 0.1          
Maturities of Long-term Debt [Abstract]                        
Total Long-Term Debt Including Current Maturities       15.3   11.1 15.3          
Line of Credit Facility [Abstract]                        
Total Loan Forgiveness           $ 2.1 $ 2.1 $ 2.1        
Annual Forgiveness Percent           43.00% 43.00% 43.00%        
Loan With Fond Du Lac County Economic Development Corporation Due 2021 [Member] | Maximum [Member]                        
Line of Credit Facility [Abstract]                        
Annual Forgiveness Percent           43.00%            
Notes Due 2027 [Member]                        
Long-term Debt [Abstract]                        
Total Long-Term Debt Including Current Maturities       162.5   $ 162.5 $ 162.5          
Interest Rate           7.125%            
Due date           2027            
Discount on Long-term Debt       0.4   $ 0.3 0.4          
Debt Issuance Costs, Net       0.4   0.4 0.4          
Maturities of Long-term Debt [Abstract]                        
Total Long-Term Debt Including Current Maturities       162.5   162.5 162.5          
Notes Payable Through 2028 [Member]                        
Long-term Debt [Abstract]                        
Total Long-Term Debt Including Current Maturities       6.9   $ 5.9 6.9          
Interest Rate           5.892%            
Due date           2028            
Discount on Long-term Debt       0.2   $ 0.2 0.2          
Debt Issuance Costs, Net       0.0   0.0 0.0          
Maturities of Long-term Debt [Abstract]                        
Total Long-Term Debt Including Current Maturities       6.9   5.9 6.9          
Senior Notes Due 2048 [Member] [Member]                        
Long-term Debt [Abstract]                        
Total Long-Term Debt Including Current Maturities       176.5   $ 176.8 176.5          
Interest Rate           6.50%            
Due date           2048            
Discount on Long-term Debt       0.0   $ 0.0 0.0          
Debt Issuance Costs, Net       8.5   8.2 8.5          
Maturities of Long-term Debt [Abstract]                        
Total Long-Term Debt Including Current Maturities       176.5   $ 176.8 176.5          
Line of Credit Facility [Abstract]                        
Debt Instrument, Redemption Price, Triggering Event           101.00%            
Term Loan Due 2023 [Member]                        
Long-term Debt [Abstract]                        
Total Long-Term Debt Including Current Maturities [3],[4]       $ 339.7   $ 305.0 $ 339.7          
Interest Rate       4.10%   3.50% 4.10%          
Due date           2023            
Discount on Long-term Debt       $ 0.0   $ 0.0 $ 0.0          
Debt Issuance Costs, Net       1.6   1.3 1.6          
Maturities of Long-term Debt [Abstract]                        
Total Long-Term Debt Including Current Maturities [3],[4]       339.7   305.0 339.7          
Unsecured Debt [Member]                        
Line of Credit Facility [Abstract]                        
Debt Instrument, Face Amount                   800.0    
6.625% Senior Notes due 2049 [Member]                        
Long-term Debt [Abstract]                        
Total Long-Term Debt Including Current Maturities       120.5   $ 120.6 120.5          
Interest Rate           6.625%            
Due date           2049            
Discount on Long-term Debt       0.0   $ 0.0 0.0          
Debt Issuance Costs, Net       4.5   4.4 4.5          
Maturities of Long-term Debt [Abstract]                        
Total Long-Term Debt Including Current Maturities       $ 120.5   120.6 $ 120.5          
Bridge Loan [Member] | Unsecured Debt [Member]                        
Line of Credit Facility [Abstract]                        
Line of Credit Facility, Maximum Borrowing Capacity                       $ 1,100.0
Bridge Facility, Line of Credit Amount Terminated                     $ 300.0  
Line of Credit Facility, Capacity Available for Specific Purpose Other than for Trade Purchases                     $ 800.0  
Line of Credit [Member]                        
Line of Credit Facility [Abstract]                        
Line of Credit Facility, Remaining Borrowing Capacity           387.9            
Letters of Credit Outstanding, Amount           12.1            
Line of Credit Facility, Increase (Decrease), Other, Net           $ 100.0            
Proceeds from Lines of Credit         $ 655.0              
Line of Credit Facility, Commitment Fee Percentage           0.15%            
Line of Credit [Member] | Minimum [Member]                        
Line of Credit Facility [Abstract]                        
Line of Credit Facility, Commitment Fee Percentage           0.125%            
Line of Credit [Member] | Maximum [Member]                        
Line of Credit Facility [Abstract]                        
Line of Credit Facility, Commitment Fee Percentage           0.35%            
Line of Credit [Member] | London Interbank Offered Rate (LIBOR) [Member]                        
Line of Credit Facility [Abstract]                        
Line of Credit Facility, Interest Rate During Period           1.10%            
Line of Credit [Member] | London Interbank Offered Rate (LIBOR) [Member] | Minimum [Member]                        
Line of Credit Facility [Abstract]                        
Line of Credit Facility, Interest Rate During Period           1.00%            
Line of Credit [Member] | London Interbank Offered Rate (LIBOR) [Member] | Maximum [Member]                        
Line of Credit Facility [Abstract]                        
Line of Credit Facility, Interest Rate During Period           1.90%            
Line of Credit [Member] | Base Rate [Member]                        
Line of Credit Facility [Abstract]                        
Line of Credit Facility, Interest Rate During Period           0.10%            
Line of Credit [Member] | Base Rate [Member] | Minimum [Member]                        
Line of Credit Facility [Abstract]                        
Line of Credit Facility, Interest Rate During Period           0.00%            
Line of Credit [Member] | Base Rate [Member] | Maximum [Member]                        
Line of Credit Facility [Abstract]                        
Line of Credit Facility, Interest Rate During Period           0.90%            
Senior Notes Due 2021 [Member]                        
Long-term Debt [Abstract]                        
Interest Rate       4.625%     4.625%          
Senior Notes Due 2021 [Member] | Unsecured Debt [Member]                        
Line of Credit Facility [Abstract]                        
Senior Notes                 $ 150.0      
6.375% Senior Notes due 2049 [Member]                        
Line of Credit Facility [Abstract]                        
Debt Instrument, Redemption Price, Triggering Event           101.00%            
6.625% Senior Notes due 2049 [Member]                        
Line of Credit Facility [Abstract]                        
Debt Instrument, Redemption Price, Triggering Event           101.00%            
Senior Notes Due 2049 [Member] | Unsecured Debt [Member]                        
Line of Credit Facility [Abstract]                        
Debt Instrument, Face Amount $ 230.0 $ 125.0                    
Proceeds from Issuance of Debt $ 222.0 $ 120.5                    
Senior Notes Due 2048 [Member] [Member] | Unsecured Debt [Member]                        
Line of Credit Facility [Abstract]                        
Debt Instrument, Face Amount     $ 185.0                  
Proceeds from Issuance of Debt     $ 176.5                  
Term Loan Due 2023 [Member] | Unsecured Debt [Member]                        
Line of Credit Facility [Abstract]                        
Debt Instrument, Face Amount                   350.0    
364 Day Tranche Loan [Member] | Unsecured Debt [Member]                        
Line of Credit Facility [Abstract]                        
Debt Instrument, Face Amount                   300.0    
Term Loan Due 2021 [Member] | Unsecured Debt [Member]                        
Line of Credit Facility [Abstract]                        
Debt Instrument, Face Amount                   $ 150.0    
[1] Included in Senior notes, 4.625 percent due 2021 at December 31, 2018, is the aggregate fair value related to the fixed-to-floating interest rate swap as discussed in Note 14 – Financial Instruments.
[2] .
[3] As of December 31, 2019 and December 31, 2018, the interest rate was 3.50% and 4.10%, respectively.
[4] Beginning in December 2018, scheduled repayment of the 5-year term loan occurs each March, June, September and December equal to 2.50% of the aggregate principal amount of $350.0 million. The remaining principal amount is due August 2023.