CONSOLIDATED STATEMENTS OF STOCKHOLDERS' (DEFICIT) EQUITY - USD ($) shares in Millions, $ in Millions	Total	Redeemable non-controlling interest	Common Stock	Treasury Stock	Additional Paid in Capital	Retained Earnings	Accumulated Other Comprehensive (Loss) Income
Balance at beginning of period at Dec. 31, 2013		$ 11.5
Balance at beginning of period (in shares) at Dec. 31, 2013			99.2	38.6
Balance at beginning of period at Dec. 31, 2013	$ 118.6	0.0	$ 1.0	$ (1,193.1)	$ 396.5	$ 927.9	$ (13.7)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	108.9					108.9
Net income (loss) attributable to noncontrolling interests		1.1
Adjustment to pension liability, net of tax	(5.6)						(5.6)
Derivative instruments accounted for as hedges, net of tax	2.0						2.0
Foreign currency adjustments	(38.4)						(38.4)
Exercise of stock options (in shares)				(0.2)
Exercise of stock options	4.3			$ 2.5	1.8
Issuances of PRSUs, RSUs and DSUs (shares)				(0.1)
Issuances of PRSUs, RSUs, and DSUs	0.0			$ 1.5	(1.5)
Tax adjustments related to stock compensation	1.7				1.7
Treasury stock repurchased	(2.2)			$ (2.2)
Amortization of unearned stock-based compensation	13.4				13.4
Balance at end of period at Dec. 31, 2014		12.6
Balance at end of period (in shares) at Dec. 31, 2014			99.2	38.3
Balance at ending of period at Dec. 31, 2014	202.7	0.0	$ 1.0	$ (1,191.3)	411.9	1,036.8	(55.7)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	73.5					73.5
Net income (loss) attributable to noncontrolling interests		1.2
Distributions paid to non-controlling interest		(1.4)
Adjustment to pension liability, net of tax	1.0						1.0
Derivative instruments accounted for as hedges, net of tax	6.0						6.0
Foreign currency adjustments	(61.4)						(61.4)
Exercise of stock options (in shares)				(1.3)
Exercise of stock options	20.4			$ 16.5	3.9
Treasury shares issued to CEO (in shares)				(0.1)
Treasury stock issued to CEO	5.0			$ 0.9	4.1
Issuances of PRSUs, RSUs and DSUs (shares)				(0.1)
Issuances of PRSUs, RSUs, and DSUs	0.0			$ 0.8	(0.8)
Tax adjustments related to stock compensation	21.8				21.8
Treasury stock repurchased	(1.3)			$ (1.3)
Amortization of unearned stock-based compensation	22.5				22.5
Balance at end of period at Dec. 31, 2015		12.4
Balance at end of period (in shares) at Dec. 31, 2015			99.2	36.8
Balance at ending of period at Dec. 31, 2015	290.2	0.0	$ 1.0	$ (1,174.4)	463.4	1,110.3	(110.1)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	202.1					202.1
Net income (loss) attributable to noncontrolling interests		(4.8)
Net loss attributable to non-controlling interests	(0.8)	(0.8)
Acquisition of non-controlling interest in subsidiary	3.8	3.8
Adjustment to pension liability, net of tax	(0.8)						(0.8)
Derivative instruments accounted for as hedges, net of tax	(6.0)						(6.0)
Foreign currency adjustments	(4.5)						(4.5)
Exercise of stock options (in shares)				(0.6)
Exercise of stock options	15.7			$ 7.9	7.8
Issuances of PRSUs, RSUs and DSUs (shares)				(0.1)
Issuances of PRSUs, RSUs, and DSUs	(0.1)			$ 1.5	(1.6)
Tax adjustments related to stock compensation	7.0				7.0
Treasury stock repurchased (in shares)				8.7
Treasury stock repurchased	(533.0)			$ (533.0)
Treasury stock repurchased - PRSU/RSU/DSU releases	(2.0)			$ (2.0)
Amortization of unearned stock-based compensation	16.2				16.2
Balance at end of period at Dec. 31, 2016		7.6
Balance at end of period (in shares) at Dec. 31, 2016			99.2	44.8
Balance at ending of period at Dec. 31, 2016	$ (12.2)	$ 3.0	$ 1.0	$ (1,700.0)	$ 492.8	$ 1,312.4	$ (121.4)