CONDENSED CONSOLIDATED STATEMENTS OF TOTAL EQUITY - USD ($) shares in Millions, $ in Millions	Total	Common Stock	Additional Paid-In Capital	Retained Earnings (Accumulated Deficit)	Treasury Stock	Total Shareholders' Equity	Non-controlling Interest	Cumulative Effect, Period of Adoption, Adjustment	Cumulative Effect, Period of Adoption, Adjustment Retained Earnings (Accumulated Deficit)	Cumulative Effect, Period of Adoption, Adjustment Total Shareholders' Equity
BALANCE, beginning of period (in shares) at Dec. 31, 2018		16.6
BALANCE, beginning of period at Dec. 31, 2018	$ 337.2		$ 329.6	$ 16.2	$ (33.4)	$ 312.4	$ 24.8
Increase (Decrease) in Stockholders' Equity
Stock-based compensation	0.6		1.7		(1.1)	0.6
Stock options exercised	0.2		0.2			0.2
Net income (loss)	(2.6)			(2.7)		(2.7)	0.1
BALANCE, end of period (in shares) at Mar. 31, 2019		16.6
BALANCE, end of period at Mar. 31, 2019	335.4		331.5	13.5	(34.5)	310.5	24.9
BALANCE, beginning of period (in shares) at Dec. 31, 2018		16.6
BALANCE, beginning of period at Dec. 31, 2018	337.2		329.6	16.2	(33.4)	312.4	24.8
Increase (Decrease) in Stockholders' Equity
Net income (loss)	(1.7)
BALANCE, end of period (in shares) at Jun. 30, 2019		16.7
BALANCE, end of period at Jun. 30, 2019	344.6		340.9	14.2	(35.6)	319.5	25.1
BALANCE, beginning of period (in shares) at Mar. 31, 2019		16.6
BALANCE, beginning of period at Mar. 31, 2019	335.4		331.5	13.5	(34.5)	310.5	24.9
Increase (Decrease) in Stockholders' Equity
Stock-based compensation	8.3		9.4		(1.1)	8.3
Restricted stock vesting (in shares)		0.1
Restricted stock vesting	0.0
Net income (loss)	0.9			0.7		0.7	0.2
BALANCE, end of period (in shares) at Jun. 30, 2019		16.7
BALANCE, end of period at Jun. 30, 2019	344.6		340.9	14.2	(35.6)	319.5	25.1
BALANCE, beginning of period (in shares) at Dec. 31, 2019		16.7
BALANCE, beginning of period at Dec. 31, 2019	369.6		348.9	31.1	(36.6)	343.4	26.2	$ (3.3)	$ (3.3)	$ (3.3)
Increase (Decrease) in Stockholders' Equity
Transfer of non-controlling interest (Note 9)	0.0		3.3			3.3	(3.3)
Stock-based compensation	2.6		3.7		(1.1)	2.6
Net income (loss)	(2.8)			(3.1)		(3.1)	0.3
BALANCE, end of period (in shares) at Mar. 31, 2020		16.7
BALANCE, end of period at Mar. 31, 2020	366.1		355.9	24.7	(37.7)	342.9	23.2
BALANCE, beginning of period (in shares) at Dec. 31, 2019		16.7
BALANCE, beginning of period at Dec. 31, 2019	369.6		348.9	31.1	(36.6)	343.4	26.2	$ (3.3)	$ (3.3)	$ (3.3)
Increase (Decrease) in Stockholders' Equity
Net income (loss)	3.7
BALANCE, end of period (in shares) at Jun. 30, 2020		16.7
BALANCE, end of period at Jun. 30, 2020	374.9		358.4	31.3	(37.9)	351.8	23.1
BALANCE, beginning of period (in shares) at Mar. 31, 2020		16.7
BALANCE, beginning of period at Mar. 31, 2020	366.1		355.9	24.7	(37.7)	342.9	23.2
Increase (Decrease) in Stockholders' Equity
Stock-based compensation	2.3		2.5		(0.2)	2.3
Net income (loss)	6.5			6.6		6.6	(0.1)
BALANCE, end of period (in shares) at Jun. 30, 2020		16.7
BALANCE, end of period at Jun. 30, 2020	$ 374.9		$ 358.4	$ 31.3	$ (37.9)	$ 351.8	$ 23.1