Financial Instruments - Additional Information (Details) - USD ($)	3 Months Ended	6 Months Ended		12 Months Ended
	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015	Dec. 31, 2015
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Transfers from Level 2 to Level 1		$ 0
Transfer from fair value measurement level 1 to level 2		0
Gross unrealized gains or losses for cash equivalent and marketable securities				$ 0
Securities that were in an unrealized loss position for more than 12 months.				0
Gains / losses on derivative instruments	$ 0		$ 0
Foreign currency forward contracts
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Unrealized gain related to effective portion of changes in fair value of foreign currency forward contracts		1,000,000
Reclassification from accumulated other comprehensive income into earnings over next 12 month		600,000
Notional value		$ 93,300,000.0		60,800,000.0
Foreign currency forward contracts | Minimum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Derivative, maturity		3 months
Foreign currency forward contracts | Maximum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Derivative, maturity		18 months
Level 3
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Securities within Level 3 of the fair value hierarchy				$ 0