Comprehensive Income (Reclassifications out of Accumulated Other Comprehensive Loss) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended			6 Months Ended
	Jun. 30, 2014		Jun. 30, 2013	Jun. 30, 2014		Jun. 30, 2013
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Unrealized net gains on available-for-sale securities	$ 1,452		$ (599)	$ (3,767)		$ (1,351)
Unrealized net gains on cash flow hedges	(551,885)		(527,256)	(1,096,491)		(1,028,633)
Net income	53,024		64,461	108,963		124,149
Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net income	2,353			3,813
Unrealized Gain on Available-for-sale Securities [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Unrealized net gains on available-for-sale securities	702			865
Unrealized Gain on Derivative Instruments [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Unrealized net gains on cash flow hedges	$ 1,651	[1]		$ 2,948	[1]

[1] * Operating expenses amounts allocated to Research and development, Sales, marketing and services, and General and administrative are not individually significant.