Comprehensive Income (Reclassifications out of Accumulated Other Comprehensive Loss) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended			9 Months Ended
	Sep. 30, 2014		Sep. 30, 2013	Sep. 30, 2014		Sep. 30, 2013
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Unrealized net gains on available-for-sale securities	$ (2,235)		$ 1,400	$ (6,002)		$ 49
Unrealized net gains on cash flow hedges	(564,412)		(501,431)	(1,660,903)		(1,530,064)
Net income	47,532		76,730	156,495		200,879
Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net income	1,596			5,409
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	96			961
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	$ 1,500	[1]		$ 4,448	[1]

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