Annual report pursuant to Section 13 and 15(d)

Treasury and Preferred Stock (Details)

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Treasury and Preferred Stock (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Equity [Abstract]      
Payments for Repurchase of Common Stock $ 130.0 $ 120.3 $ 120.0
Stock Repurchase Program, Remaining Number of Shares Authorized to be Repurchased 110,000,000    
Treasury Stock Activity [Roll Forward]      
Balance at January 1 13,221,000 11,725,000 9,844,000
Compensation Plans and Other (547,000) (1,199,000) (458,000)
Share Repurchases 2,327,000 2,695,000 2,339,000
Balance at December 31 15,001,000 13,221,000 11,725,000