Condensed Consolidated Statements of Comprehensive Income (Loss) (Unaudited) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Net income (loss)	$ 174,833	$ (33,172)	$ 377,592	$ (220,672)
Unrealized gains on investments:
Unrealized holding gains arising during the period	9,281	1,480	13,766	8,946
Less: Reclassification adjustment for net (losses) gains included in net income (loss)	(392)	554	132	575
Net unrealized gains on investments	9,673	926	13,634	8,371
Other comprehensive income	9,673	926	13,634	8,371
Comprehensive income (loss)	$ 184,506	$ (32,246)	$ 391,226	$ (212,301)