Share-Based Compensation Plans - Options Activity (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Shares (in thousands)
Beginning balance (in shares)	844,800
Forfeited or expired (in shares)	(6,800)
Options Exercised (shares)	(149,700)
Ending balance (in shares)	688,300
Beginning Balances - Exercise Price (in dollars per share)	$ 25.88
Cancelled (in dollars per share)	28.32
Options Exercised - Exercise Price (in dollars per share)	25.20
Ending Balance - Exercise Price (in dollars per share)	$ 26.01
Exercisable Options - Shares	688,300	700,000	1,200,000
Exercise price (in dollars per share)	$ 26.01	$ 26.44	$ 30.92
Outstanding Options - Remaining Term Years	1 year 9 months 18 days
Exercisable Options - Remaining Term Years	1 year 9 months 18 days
Outstanding Options - Average Intrinsic Value	$ 0.0
Exercisable Options - Average Intrinsic Value	$ 2.8
Market price (in dollars per share)	$ 28.86