Consolidated Statements of Equity - USD ($) $ in Millions	Total	Adjustment	Common Stock	Paid-In Capital	Retained Deficit	Retained Deficit Adjustment	Accum. Other Comprehensive Income	Common Stock In Treasury
Balance at beginning of period at Dec. 31, 2017	$ 314.7		$ 0.5	$ 1,309.8	$ (742.3)		$ 250.1	$ (503.4)
Balance at beginning of period (Accounting Standards Update 2016-01) at Dec. 31, 2017		$ 12.0				$ 12.0
Balance at beginning of period (Accounting Standards Update 2014-09) at Dec. 31, 2017		4.0				4.0
Balance at beginning of period (Accounting Standards Update 2016-16) at Dec. 31, 2017		(0.2)				(0.2)
Increase (Decrease) in Stockholders' Equity
Net income	81.2				81.2
Other comprehensive income (loss), net	(5.2)						(5.2)
Incentive plan activity	10.3			10.3
Long-term incentive compensation expense	11.6			11.6
Restricted stock unit vesting	(8.7)			(36.3)				27.6
Stranded income tax effects resulting from tax reform - See Note 3	(4.8)				(4.8)
Adjustment related to redeemable noncontrolling interest (Note 15)	0.0
Balance at end of period at Dec. 31, 2018	414.9		0.5	1,295.4	(650.1)		244.9	(475.8)
Increase (Decrease) in Stockholders' Equity
Net income	65.3				65.3
Other comprehensive income (loss), net	(0.6)						(0.6)
Incentive plan activity	13.0			13.0
Long-term incentive compensation expense	10.8			10.8
Restricted stock unit vesting	(6.6)			(22.4)				15.8
Adjustment related to redeemable noncontrolling interest (Note 15)	5.6			5.6
Balance at end of period at Dec. 31, 2019	$ 502.4	$ (0.5)	0.5	1,302.4	(584.8)	$ (0.5)	244.3	(460.0)
Increase (Decrease) in Stockholders' Equity
Impact of adoption of ASU 2016-13 - See Note 3	us-gaap:AccountingStandardsUpdate201613Member
Net income	$ 97.2				97.2
Other comprehensive income (loss), net	4.2						4.2
Incentive plan activity	17.5			17.5
Long-term incentive compensation expense	12.8			12.8
Restricted stock unit vesting	(4.4)			(12.8)				8.4
Adjustment related to redeemable noncontrolling interest (Note 15)	0.0
Balance at end of period at Dec. 31, 2020	$ 629.2		$ 0.5	$ 1,319.9	$ (488.1)		$ 248.5	$ (451.6)