Consolidated Statements of Equity Statement - USD ($) $ in Millions	Total	Common Stock Including Additional Paid in Capital [Member]	Retained Earnings [Member]	Treasury Stock [Member]	AOCI Attributable to Parent [Member]	Noncontrolling Interest [Member]
Beginning Balance at Dec. 31, 2016	$ 372.4	$ 488.0	$ 619.3	$ (804.9)	$ 66.4	$ 3.6
Net income (loss)	10.4		11.2			(0.8)
Repurchase of common stock	(65.0)			(65.0)
Stock-based compensation	11.0	11.0
Exercise of stock options	16.1	(18.9)		35.0
Adjustment to Additional Paid In Capital, Tax Payments Related to Stock-based Compensation	(2.5)	(2.5)
Shares issued	0.7	(2.1)		2.8
Dividends declared	(57.4)		(57.4)
Noncontrolling Interest, Increase from Subsidiary Equity Issuance	4.1					4.1
Other comprehensive income (loss)	(26.5)				(26.5)
Other comprehensive income (loss)	0.0
Ending Balance at Dec. 31, 2017	263.3	475.5	573.1	(832.1)	39.9	6.9
Net income (loss)	166.8		167.6			(0.8)
Repurchase of common stock	(80.0)			(80.0)
Stock-based compensation	18.6	18.6
Exercise of stock options	6.4	(4.2)		10.6
Adjustment to Additional Paid In Capital, Tax Payments Related to Stock-based Compensation	(2.9)	(2.9)
Shares issued	0.8	(5.2)		6.0
Dividends declared	(64.3)		(64.3)
Other comprehensive income (loss)	25.8				25.8
Other comprehensive income (loss)	0.0
Ending Balance at Dec. 31, 2018	337.0	481.8	676.7	(895.5)	67.9	6.1
Ending Balance (Accounting Standards Update 2018-02 [Member]) at Dec. 31, 2018					2.2
Cumulative Effect of New Accounting Principle in Period of Adoption | Difference between Revenue Guidance in Effect before and after Topic 606 [Member]	2.5		2.5
Cumulative Effect of New Accounting Principle in Period of Adoption | Accounting Standards Update 2018-02 [Member]	0.0		(2.2)		2.2
Net income (loss)	126.7		126.3			0.4
Repurchase of common stock	(29.8)			(29.8)
Stock-based compensation	14.6	14.6
Exercise of stock options	19.1	(5.0)		24.1
Adjustment to Additional Paid In Capital, Tax Payments Related to Stock-based Compensation	(4.9)	(4.9)
Shares issued	1.1	(7.9)		9.0
Dividends declared	(72.5)		(72.5)
Other comprehensive income (loss)	10.9				10.9
Other comprehensive income (loss)	0.0
Ending Balance at Dec. 31, 2019	$ 402.2	$ 478.6	$ 730.5	$ (892.2)	$ 78.8	$ 6.5