Consolidated Statements Of Comprehensive Income (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Statement of Other Comprehensive Income [Abstract]
Net income	$ 26,136	$ 3,416	$ 60,909	$ 34,814
Unrealized gains on available-for-sale securities, net of tax	(492)	5,445	4,358	6,638
Unrealized gains on cash flow hedging instruments, net of tax	(1,335)	(4,398)	1,029	(1,592)
Foreign currency translation adjustment, net of tax	(145)	472	390	1,006
Total other comprehensive income	(1,972)	1,519	5,777	6,052
Comprehensive income	$ 24,164	$ 4,935	$ 66,686	$ 40,866