Derivative and Hedging Activities Derivative and Hedging Activities Additional Information (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2016	Dec. 31, 2015
Derivative [Line Items]
Accumulated Other Comprehensive Income (Loss), Cumulative Changes in Net Gain (Loss) from Cash Flow Hedges, Effect Net of Tax	[1]	$ 0	$ (246)
Forward Contracts [Member]
Derivative [Line Items]
Derivative, Term of Contract		12 months
Compensating Balance, Amount		$ 2,500
Forward Contracts [Member] | Designated as Hedging Instrument [Member]
Derivative [Line Items]
Derivative, Term of Contract		12 months
Forward Contracts [Member] | Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Derivative, Term of Contract		3 months
Cash Flow Hedging [Member] | Forward Contracts [Member] | Designated as Hedging Instrument [Member]
Derivative [Line Items]
Derivative, Term of Contract		12 months
Other Comprehensive Income (Loss) [Member] | Designated as Hedging Instrument [Member]
Derivative [Line Items]
Net Unrealized Losses from Cash Flow Hedges to be reclassified to earnings within next twelve months			133
Long [Member] | Foreign Exchange Forward [Member] | Designated as Hedging Instrument [Member]
Derivative [Line Items]
Derivative Asset, Outstanding		$ 0	12,984
Long [Member] | Foreign Exchange Forward [Member] | Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Derivative Asset, Outstanding		$ 4,056	$ 6,942

[1] See Consolidated Statements of Comprehensive Loss for the amounts related to cash flow hedges and investments that were reclassified into the Consolidated Statements of Operations for the periods presented.