Derivative Instruments and Hedging Activities Open Foreign Currency Contracts (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Derivative [Line Items]
Derivative, Fair Value, Net	$ (7,179)	$ 21
Cash Flow Hedging | Foreign currency contracts
Derivative [Line Items]
Notional Amounts (in U.S. dollars)	100,302
Derivative, Fair Value, Net	(2,570)
Canadian Dollar | Cash Flow Hedging | Foreign currency contracts
Derivative [Line Items]
Notional Amounts (in U.S. dollars)	40,550
Derivative, Fair Value, Net	38
Japanese Yen | Cash Flow Hedging | Foreign currency contracts
Derivative [Line Items]
Notional Amounts (in U.S. dollars)	22,201
Derivative, Fair Value, Net	(1,008)
Mexican Peso | Cash Flow Hedging | Foreign currency contracts
Derivative [Line Items]
Notional Amounts (in U.S. dollars)	34,060
Derivative, Fair Value, Net	$ (1,991)