Derivative Financial Instruments - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014	Dec. 31, 2014
Derivative [Line Items]
Deferred gains (losses) on derivative instruments expected to be reclassified into earnings during the next 12 months	$ (1.7)		$ (1.7)
Foreign Currency Forward [Member]
Derivative [Line Items]
Notional amounts	19.4		$ 19.4		$ 29.3
Remaining maturity of outstanding instruments			11 months
Foreign Currency Forward [Member] | Not Designated as Hedging Instrument [Member] | Foreign Currency Gain (Loss) [Member]
Derivative [Line Items]
Gain (loss) related to changes in fair value of derivative instruments		$ 0.2	$ 0.3	$ 0.1
Foreign Currency Forward [Member] | Cash Flow Hedging [Member]
Derivative [Line Items]
Gain (loss) on settlement of derivative instruments	(0.7)	$ (0.6)	(2.1)	$ (1.8)
Foreign Currency Forward [Member] | Cash Flow Hedging [Member] | Other current liabilities [Member]
Derivative [Line Items]
Foreign currency forward contracts - liability position	$ 1.7		$ 1.7		$ 3.1