Long-term Equity-based Compensation - Option and SAR Activity (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Shares Subject to Options at Beginning of Year	2,265,711
Weighted Average Exercise Price Per Share at Beginning of Year	$ 39.74
Grants in Period	397,532
Grants in Period, Weighted Average Exercise Price	$ 37.51
Exercises in Period	(629,625)
Exercises in Period, Weighted Average Exercise Price	$ 31.84
Forfeitures and Expirations in Period	(605,461)
Forfeitures and Expirations in Period, Weighted Average Exercise Price	$ 46.45
Shares Subject to Options at End of Year	1,428,157	2,265,711
Weighted Average Exercise Price Per Share at End of Year	$ 39.75	$ 39.74
Outstanding at End of Year, Weighted Average Remaining Contractual Term	5 years 4 months 24 days
Outstanding at End of Year, Intrinsic Value	$ 2.1
Vested and Expected to Vest, Outstanding at End of Year	1,393,530
Vested and Expected to Vest, Outstanding, Weighted Average Exercise Price	$ 39.84
Vested and Expected to Vest, Outstanding, Weighted Average Remaining Contractual Term	5 years 3 months 18 days
Vested and Expected to Vest, Outstanding, Aggregate Intrinsic Value	$ 2.0
Vested and Expected to Vest, Exercisable at End of Year	978,437
Vested and Expected to Vest, Exercisable at End of Year, Weighted Average Exercise Price	$ 41.02
Vested and Expected to Vest, Exercisable at End of Year, Weighted Average Remaining Contractual Term	3 years 9 months 18 days
Vested and Expected to Vest, Exercisable at End of Year, Aggregate Intrinsic Value	$ 1.6
Weighted-average grant-date fair values (per share)	$ 7.85	$ 10.49	$ 10.20
Total intrinsic value	$ 4.6	$ 0.4	$ 4.1
Cash received from exercises of Tandem Awards	3.9	0.5	1.7
Total tax benefit realized for tax deductions from exercise of Tandem Awards	$ 1.6	$ 0.1	$ 1.4