Derivative Instruments and Hedging Activities (Details 2) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010
Derivative Instruments, Gain (Loss) [Line Items]
Net unrealized gain on outstanding interest rate swaps	$ (366)	$ 366
Foreign currency forward contracts [Member] | Non-designated derivatives [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Net unrealized gain on outstanding interest rate swaps	0	0
Gain/(loss) reclassified from AOCL to "other income"	0	0
Gain/(loss) recognized through "other income"	(546)	2,253
Foreign currency forward contracts [Member] | Cash flow hedges [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Net unrealized gain on outstanding interest rate swaps	(3,061)	1,187
Gain/(loss) reclassified from AOCL to "other income"	1,604
Gain/(loss) recognized through "other income"	0
Interest Rate Swaps [Member] | Cash flow hedges [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Net unrealized gain on outstanding interest rate swaps		366
Gain/(loss) reclassified from AOCL to "other income"	366
Gain/(loss) recognized through "other income"	$ 0	$ (96)