Derivatives and Hedging Activities (Fair Value of Forward Exchange Contracts Not Designated as Hedging Instruments) (Details) (Not Designated as a Hedging Instrument, Forward Exchange Contracts, USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Not Designated as a Hedging Instrument | Forward Exchange Contracts
Derivative [Line Items]
Gain (loss) recognized in income	$ 8,464	$ (4,352)	$ (7,089)