Long-term Equity-based Compensation - Option and SAR Activity (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Shares Subject to Options at Beginning of Year	1,428,157
Weighted Average Exercise Price Per Share at Beginning of Year	$ 39.75
Grants in Period	506,675
Grants in Period, Weighted Average Exercise Price	$ 31.09
Exercises in Period	251,522
Exercises in Period, Weighted Average Exercise Price	$ 34.04
Forfeitures and Expirations in Period	(377,187)
Forfeitures and Expirations in Period, Weighted Average Exercise Price	$ 43.72
Shares Subject to Options at End of Year	1,306,123	1,428,157
Weighted Average Exercise Price Per Share at End of Year	$ 36.35	$ 39.75
Outstanding at End of Year, Weighted Average Remaining Contractual Term	6 years 6 months
Outstanding at End of Year, Intrinsic Value	$ 11.5
Vested and Expected to Vest, Outstanding at End of Year	1,254,165
Vested and Expected to Vest, Outstanding, Weighted Average Exercise Price	$ 36.49
Vested and Expected to Vest, Outstanding, Weighted Average Remaining Contractual Term	6 years 4 months 26 days
Vested and Expected to Vest, Outstanding, Aggregate Intrinsic Value	$ 10.9
Vested and Expected to Vest, Exercisable at End of Year	701,486
Vested and Expected to Vest, Exercisable at End of Year, Weighted Average Exercise Price	$ 38.32
Vested and Expected to Vest, Exercisable at End of Year, Weighted Average Remaining Contractual Term	4 years 9 months 17 days
Vested and Expected to Vest, Exercisable at End of Year, Aggregate Intrinsic Value	$ 5.3
Weighted-average grant-date fair values (per share)	$ 5.17	$ 7.85	$ 10.49
Cash received from exercises of Tandem Awards	$ 3.5	$ 3.9	$ 0.5
Total tax benefit realized for tax deductions from exercise of Tandem Awards	$ 0.7	$ 1.6	$ 0.1