Consolidated Statements of Comprehensive (Loss) Income (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Consolidated Statements of Comprehensive (Loss) Income
Net (loss) income	$ (233,195)us-gaap_NetIncomeLoss	$ (794,339)us-gaap_NetIncomeLoss	$ 211,971us-gaap_NetIncomeLoss
Other comprehensive (loss) income, net of tax:
Foreign currency translation adjustment during the period	(1,665)	(1,245)	425
Change in fair value of corporate debt securities
Unrealized holding (losses) gains on corporate debt securities arising during the period		(98)	279
Less: Reclassification adjustments for gains included in net (loss) income		(1,296)
Change in fair value of corporate debt securities, net		(1,394)	279
Other comprehensive (loss) income	(1,665)	(2,639)	704
Comprehensive (loss) income	$ (234,860)	$ (796,978)	$ 212,675

Amount after tax of increase (decrease) in equity from transactions and other events and circumstances from net income and other comprehensive income. Excludes changes in equity resulting from investments by owners and distributions to owners.

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