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
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, 2019		16.7
BALANCE, beginning of period at Dec. 31, 2019	369.6		348.9	31.1	(36.6)	343.4	26.2
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