Other Comprehensive Income (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
Other comprehensive income (loss), before tax amount
Foreign currency translation, before tax amount		$ (4,570)	$ 3,878	$ 1,029
Unrealized holding gains (losses) on available-for-sale securities, before tax amount	(38,502)	40,692	(18,933)	77,760
Recognition of previously unrealized (gains) losses on available-for-sale securities included in net income (loss), before tax amount	1,784	(49,221)	1,722	(54,565)
Other comprehensive income (loss), before tax amount	(36,718)	(13,099)	(13,333)	24,224
Other comprehensive income loss tax (expense) benefit
Unrealized holding gains (losses) on available-for-sale securities, tax (expense) benefit	14,074	(14,343)	6,923	(27,887)
Recognition of previously unrealized (gains) losses on available-for-sale securities included in net income (loss), tax (expense) benefit	(653)	17,990	(630)	19,941
Other comprehensive income (loss), tax (expense) benefit	13,421	3,647	6,293	(7,946)
Other comprehensive income (loss):
Foreign currency translation adjustments, net of tax amount		(4,570)	3,878	1,029
Unrealized holding gains (losses) on available-for-sale securities, net of tax amount	(24,428)	26,349	(12,010)	49,873
Recognition of previously unrealized (gains) losses on available-for-sale securities included in net income (loss), net of tax amount	1,131	(31,231)	1,092	(34,624)
Other comprehensive income (loss), net of tax	$ (23,297)	$ (9,452)	$ (7,040)	$ 16,278