Earnings Per Share (Details) - shares	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Weighted Average Number of Shares Outstanding Basic and Diluted [Line Items]
Common stock, shares, outstanding	105,640,003	111,911,290
Repurchased and retired common stock	7,690,628	2,755,642
Treasury Stock, Shares, Acquired	700,000	400,000
Weighted Average Number of Shares Outstanding Reconciliation [Abstract]
Weighted-average number of common shares outstanding - basic	108,800,000	113,700,000	113,500,000
Adjusted weighted average shares and assumed conversions - diluted	110,600,000	116,300,000	115,700,000
Potentially dilutive shares excluded from computation of dilutive earnings per share	5,500,000	4,300,000	4,900,000
Stock options
Weighted Average Number of Shares Outstanding Reconciliation [Abstract]
Incremental common shares attributable to share-based payment arrangements	200,000	100,000	0
Stock-settled stock appreciation rights
Weighted Average Number of Shares Outstanding Reconciliation [Abstract]
Incremental common shares attributable to share-based payment arrangements	300,000	600,000	900,000
Restricted stock units
Weighted Average Number of Shares Outstanding Reconciliation [Abstract]
Incremental common shares attributable to share-based payment arrangements	1,300,000	1,900,000	1,300,000