Fair Value Measurements - Derivative Financial Instruments (Details) - Foreign Exchange Contract [Member] - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Derivative [Line Items]
Notional amount of foreign currency derivative contracts	$ 44,438	$ 43,431
Fair value of foreign currency derivatives contracts	42	(208)
Other Expense [Member]
Derivative [Line Items]
Gain (losses) on Derivative Instruments Recognized in Income Statement	73	(54)
Not Designated as Hedging Instrument [Member] | Prepaid Expenses and Other Current Assets [Member]
Derivative [Line Items]
Derivative Assets	108	102
Not Designated as Hedging Instrument [Member] | Accrued Expenses and Other Liabilities [Member]
Derivative [Line Items]
Derivative Liabilities	$ 66	$ 310