Derivative Instruments (Cash Flow Hedges) (Details) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Recognized in OCI on Derivatives (Effective Portion)	$ 8,062,000	$ 7,936,000	$ (2,327,000)
Amount of Gain (Loss) Reclassified from Accumulated OCI into Income (Effective Portion)	(8,302,000)	(8,599,000)	(8,940,000)
Cash Flow Hedging [Member] | Foreign exchange contract [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Loss expected to be reclassified from accumulated OCI into income effective portion over the next year	0
Cash Flow Hedging [Member] | Foreign exchange contract [Member] | Cost and sales of operating expenses [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Recognized in OCI on Derivatives (Effective Portion)	346,000	929,000	(1,419,000)
Amount of Gain (Loss) Reclassified from Accumulated OCI into Income (Effective Portion)	19,000	(13,000)	(411,000)
Cash Flow Hedging [Member] | Interest rate contract [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Loss expected to be reclassified from accumulated OCI into income effective portion over the next year	966,000
Cash Flow Hedging [Member] | Interest rate contract [Member] | Interest expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Recognized in OCI on Derivatives (Effective Portion)	7,716,000	7,007,000	(908,000)
Amount of Gain (Loss) Reclassified from Accumulated OCI into Income (Effective Portion)	$ (8,321,000)	$ (8,586,000)	$ (8,529,000)