Consolidated Statements of Shareholders' Equity - USD ($) $ in Millions	Total	Cumulative Effect, Period of Adoption, Adjustment	Common Stock	Retained Earnings	Retained Earnings Cumulative Effect, Period of Adoption, Adjustment	Accumulated Other Comprehensive Loss	Noncontrolling Interest
Shares outstanding, beginning (in shares) at Dec. 31, 2018			40,400,000
Shareholders' equity, beginning at Dec. 31, 2018	$ 473.3	$ (0.3)	$ 0.0	$ 474.2	$ (0.3)	$ (0.9)	$ 0.0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	137.2			137.5			(0.3)
Contributions from non-controlling interest	3.0						3.0
Issuance of common stock (in shares)			200,000
Issuance of common stock	$ 1.9		$ 1.9
Repurchase of common stock (in shares)	(864,233)		(900,000)
Repurchase of common stock	$ (93.0)		$ (25.7)	(67.3)
Taxes paid related to net share settlement of stock awards (in shares)			(100,000)
Taxes paid related to net share settlement of stock awards	(11.5)			(11.5)
Issuance of restricted stock awards, net of forfeitures (in usd)	0.0		$ 0.0
Issuance of restricted stock awards, net of forfeitures (in shares)			100,000
Stock-based compensation	23.8		$ 23.8
Cash dividends	(23.4)			(23.4)
Shares outstanding, ending (in shares) at Dec. 31, 2019			39,700,000
Shareholders' equity, ending at Dec. 31, 2019	511.0	$ (0.5)	$ 0.0	509.2	$ (0.5)	(0.9)	2.7
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(82.1)			(81.9)			(0.2)
Purchase of noncontrolling interest	(3.0)			(0.5)			(2.5)
Issuance of common stock (in shares)			100,000
Issuance of common stock	$ 2.4		$ 2.4
Repurchase of common stock (in shares)	(235,590)		(200,000)
Repurchase of common stock	$ (27.9)		$ (4.3)	(23.6)
Taxes paid related to net share settlement of stock awards (in shares)			(100,000)
Taxes paid related to net share settlement of stock awards	(18.7)		$ (3.6)	(15.1)
Stock-based compensation	23.7		$ 23.7
Cash dividends	(25.1)			(25.1)
Shares outstanding, ending (in shares) at Dec. 31, 2020			39,500,000
Shareholders' equity, ending at Dec. 31, 2020	367.1		$ 18.2	349.8		(0.9)	0.0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cash settlement of stock awards	(12.7)			(12.7)
Net income (loss)	249.1			249.1
Issuance of common stock (in shares)			200,000
Issuance of common stock	$ 2.5		$ 2.5
Repurchase of common stock (in shares)	(471,364)		(1,500,000)
Repurchase of common stock	$ (297.5)		$ (48.5)	(249.0)
Taxes paid related to net share settlement of stock awards (in shares)			(100,000)
Taxes paid related to net share settlement of stock awards	(16.1)			(16.1)
Stock-based compensation	27.8		$ 27.8
Cash dividends	(26.1)			(26.1)
Shares outstanding, ending (in shares) at Dec. 31, 2021			38,100,000
Shareholders' equity, ending at Dec. 31, 2021	$ 306.8		$ 0.0	$ 307.7		$ (0.9)	$ 0.0