Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended			6 Months Ended		12 Months Ended
	Jun. 30, 2015	Mar. 31, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014	Dec. 31, 2012
Other comprehensive income (loss), before tax amount
Foreign currency translation adjustments, before tax amount					$ 3,878
Unrealized holding gains (losses) on available-for-sale securities, before tax amount	$ 39,405		$ 9,586	$ 46,827	19,569
Recognition of previously unrealized (gains) losses on available-for-sale securities included in net income (loss)	(34,310)		(555)	(93,797)	(62)
Other comprehensive income (loss), before tax amount	5,095		9,031	(46,970)	23,385
Other comprehensive income loss tax (expense) benefit
Unrealized holding gains (losses) on available-for-sale securities, tax (expense) benefit	(14,490)		(3,502)	(17,234)	(7,151)
Recognition of previously unrealized (gains) losses on available-for-sale securities included in net income (loss), tax (expense) benefit	12,529		203	(28,138)	23
Other comprehensive income (loss), tax (expense) benefit	(1,961)		(3,299)	(45,372)	(7,128)
Other comprehensive income (loss):
Foreign currency translation adjustments, net of tax amount					3,878
Unrealized holding gains (losses) on available-for-sale securities, net of tax amount	24,915		6,084	29,593	12,418
Recognition of previously unrealized (gains) losses on available-for-sale securities included in net income (loss), net of tax amount	(21,781)		(352)	(121,935)	(39)
Other comprehensive income (loss), net of tax	$ 3,134		$ 5,732	$ (92,342)	$ 16,257
Deferred tax asset valuation allowance released						$ 63,000
Deferred tax asset valuation allowance reclassified from AOCI		$ 63,000