Other Comprehensive Income Related Tax Effects (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Other comprehensive income, before-tax amount
Foreign currency translation adjustments, before-tax amount	$ 3,253
Recognition of previously unrealized (gains) losses on available-for-sale securities included in net income (loss), before tax amount	(80,887)	(6,296)
Other comprehensive income, before-tax amount	(26,613)	61,504
Other comprehensive income (loss), net of tax:
Foreign currency translation adjustments, net of tax	3,253
Unrealized holding gains (losses) on available-for-sale securities, net of tax	51,021	67,800
Recognition of previously unrealized (gains) losses on available-for-sale securities included in net income (loss), net of tax	(80,887)	(6,296)
Other comprehensive income (loss), net of tax	$ (26,613)	$ 61,504