Consolidated Statements Of Comprehensive Income (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Statement of Other Comprehensive Income [Abstract]
Net income	$ 14,619	$ 34,773
Unrealized gains on available-for-sale securities, net of tax	(4,586)	4,850
Unrealized gains on cash flow hedging instruments, net of tax	1,519	2,364
Foreign currency translation adjustment, net of tax	(1,069)	535
Total other comprehensive income	(4,136)	7,749
Comprehensive income	$ 10,483	$ 42,522