Derivative Instruments and Hedging Activities - Open Foreign Currency Contracts (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Derivative [Line Items]
Derivative, Fair Value, Net	$ 358	$ (2,741)
Cash Flow Hedging | Foreign exchange contracts
Derivative [Line Items]
Notional Amounts (in US Dollars)	178,830
Derivative, Fair Value, Net	436
Cash Flow Hedging | Foreign exchange contracts | Currency, Australian Dollar
Derivative [Line Items]
Notional Amounts (in US Dollars)	4,664
Derivative, Fair Value, Net	391
Cash Flow Hedging | Foreign exchange contracts | Currency, Canadian Dollar
Derivative [Line Items]
Notional Amounts (in US Dollars)	120,589
Derivative, Fair Value, Net	422
Cash Flow Hedging | Foreign exchange contracts | Currency, Japanese Yen
Derivative [Line Items]
Notional Amounts (in US Dollars)	23,883
Derivative, Fair Value, Net	(610)
Cash Flow Hedging | Foreign exchange contracts | Currency, Mexican Peso
Derivative [Line Items]
Notional Amounts (in US Dollars)	16,875
Derivative, Fair Value, Net	182
Cash Flow Hedging | Foreign exchange contracts | Norwegian Kroner
Derivative [Line Items]
Notional Amounts (in US Dollars)	4,606
Derivative, Fair Value, Net	149
Cash Flow Hedging | Foreign exchange contracts | Currency, Swedish Krone
Derivative [Line Items]
Notional Amounts (in US Dollars)	8,213
Derivative, Fair Value, Net	$ (98)