Income Taxes - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Tax Disclosure [Line Items]
Interest and penalties increase (decrease)	$ (0.9)	$ 1.7
Unrecognized Tax Benefits	62.0	74.5	49.9
Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued	11.3	11.6
Significant (Increase) Decrease in Unrecognized Tax Benefits is Reasonably Possible, Estimated Range of Change, Lower Bound	2.4
Undistributed Earnings of Foreign Subsidiaries	42.0
Payments From Affiliate Under Tax Sharing Agreement Related To Current Year	0.3
Payments From Affiliate Under Tax Sharing Agreement Related To Prior Year	0	1.3
Payments From Affiliate Under Tax Sharing Agreement Expected In Following Year Related To Current Year	0
Operating Loss Carryforwards	389.3
Operating Loss Carryforwards Expiration In Year One	0.3
Operating Loss Carryforwards Expiration In Year Two	4.0
Operating Loss Carryforwards Expiration In Year Three	9.2
Operating Loss Carryforwards Expiration In Year Four And Thereafter	188.9
Operating Loss Carryforwards Not Subject To Expiration	186.9
Non Cash Income Tax Benefit Related To Release Of Valuation Allowance			15.8
Provision for income taxes	81.2	48.6	44.8
Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount	(4.6)	(8.9)
Foreign Tax Authority [Member]
Income Tax Disclosure [Line Items]
Operating Loss Carryforwards	244.2
Domestic Tax Authority [Member]
Income Tax Disclosure [Line Items]
Operating Loss Carryforwards	$ 145.1