CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS’ EQUITY - USD ($) shares in Millions, $ in Millions	Total	Common Stock	Treasury Stock	Additional Paid in Capital	Retained Earnings	Accumulated Other Comprehensive Loss	Non-controlling Interest
Balance at beginning of period (in shares) at Dec. 31, 2018		99.2	44.7
Balance at beginning of period at Dec. 31, 2018	$ 217.5	$ 1.0	$ (1,737.0)	$ 532.1	$ 1,513.8	$ (95.3)	$ 2.9
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	28.4				28.4
Net income attributable to non-controlling interests	0.2						0.2
Repurchase of interest in subsidiary	(1.9)						(1.9)
Foreign currency adjustments	4.0					4.0
Exercise of stock options (in shares)			(0.1)
Exercise of stock options	2.4		$ 0.8	1.6
Issuances of PRSUs, RSUs, and DSUs (in shares)			(0.2)
Issuances of PRSUs, RSUs, and DSUs	0.0		$ 3.2	(3.2)
Treasury stock repurchased	(0.8)		$ (0.8)
Treasury stock repurchased - PRSU/RSU/DSU releases (in shares)			0.1
Treasury stock repurchased - PRSU/RSU/DSU releases	(2.9)		$ (2.9)
APIC, Share-based Payment Arrangement, Increase for Cost Recognition	6.6			6.6
Balance at ending of period (in shares) at Mar. 31, 2019		99.2	44.5
Balance at end of period at Mar. 31, 2019	253.5	$ 1.0	$ (1,736.7)	537.1	1,542.2	(91.3)	1.2
Balance at beginning of period (in shares) at Dec. 31, 2019		99.2	45.4
Balance at beginning of period at Dec. 31, 2019	360.4	$ 1.0	$ (1,832.8)	575.7	1,703.3	(87.7)	0.9
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	59.7				59.7
Net income attributable to non-controlling interests	0.1						0.1
Acquisition of non-controlling interest in subsidiary	8.4						8.4
Foreign currency adjustments	(23.0)					(23.0)
Exercise of stock options	1.3		$ 0.3	1.0
Issuances of PRSUs, RSUs, and DSUs (in shares)			(0.4)
Issuances of PRSUs, RSUs, and DSUs	0.0		$ 5.3	(5.3)
Treasury stock repurchased (in shares)			2.6
Treasury stock repurchased	(187.5)		$ (187.5)
Treasury stock repurchased - PRSU/RSU/DSU releases (in shares)			0.1
Treasury stock repurchased - PRSU/RSU/DSU releases	(11.8)		$ (11.8)
APIC, Share-based Payment Arrangement, Increase for Cost Recognition	7.3			7.3
Balance at ending of period (in shares) at Mar. 31, 2020		99.2	47.7
Balance at end of period at Mar. 31, 2020	$ 208.4	$ 1.0	$ (2,026.5)	$ 578.7	$ 1,756.5	$ (110.7)	$ 9.4