Derivative Instruments and Hedging Activities Open Foreign Currency Contracts (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Derivative [Line Items]
Net Unrealized Gain (Loss)	$ (4,572)	$ 2,599
Cash Flow Hedging | Foreign Exchange Contract
Derivative [Line Items]
Notional Amounts (in U.S. Dollars)	125,773
Net Unrealized Gain (Loss)	(4,572)
Cash Flow Hedging | Foreign Exchange Contract | Australian Dollar
Derivative [Line Items]
Notional Amounts (in U.S. Dollars)	23,326
Net Unrealized Gain (Loss)	(572)
Cash Flow Hedging | Foreign Exchange Contract | Canadian Dollar
Derivative [Line Items]
Notional Amounts (in U.S. Dollars)	79,041
Net Unrealized Gain (Loss)	(2,365)
Cash Flow Hedging | Foreign Exchange Contract | Japanese Yen
Derivative [Line Items]
Notional Amounts (in U.S. Dollars)	251
Net Unrealized Gain (Loss)	41
Cash Flow Hedging | Foreign Exchange Contract | Mexican Peso
Derivative [Line Items]
Notional Amounts (in U.S. Dollars)	23,155
Net Unrealized Gain (Loss)	$ (1,676)