Foreign Exchange Risk Management - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Derivative Instruments And Hedging Activities Disclosure [Abstract]
Gross notional amount	$ 118,600,000	$ 124,300,000	$ 236,000,000
Recognized gains from forward contracts	50,300,000
Recognized losses from forward contracts		2,800,000	7,100,000
Foreign Currency Transaction Gain (Loss), before Tax	$ 22,400,000	$ 4,200,000	$ 2,800,000