Derivative Instruments and Hedging Activities Open Foreign Currency Contracts (Details) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Derivative [Line Items]
Net Unrealized Gain (Loss)	$ (8,682)	$ 2,599
Cash Flow Hedging | Foreign Exchange Contract
Derivative [Line Items]
Notional Amounts (in U.S. Dollars)	261,943
Net Unrealized Gain (Loss)	(8,682)
Cash Flow Hedging | Foreign Exchange Contract | Australian Dollar
Derivative [Line Items]
Notional Amounts (in U.S. Dollars)	21,613
Net Unrealized Gain (Loss)	(944)
Cash Flow Hedging | Foreign Exchange Contract | Canadian Dollar
Derivative [Line Items]
Notional Amounts (in U.S. Dollars)	193,261
Net Unrealized Gain (Loss)	(7,226)
Cash Flow Hedging | Foreign Exchange Contract | Japanese Yen
Derivative [Line Items]
Notional Amounts (in U.S. Dollars)	6,115
Net Unrealized Gain (Loss)	412
Cash Flow Hedging | Foreign Exchange Contract | Mexican Peso
Derivative [Line Items]
Notional Amounts (in U.S. Dollars)	40,954
Net Unrealized Gain (Loss)	$ (924)