CONSOLIDATED STATEMENTS OF OTHER COMPREHENSIVE INCOME (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
CONSOLIDATED STATEMENTS OF OTHER COMPREHENSIVE INCOME
Net income (loss)	$ 22,117	$ (5,108)
Other comprehensive (loss) income before tax:
Reduction of unrealized gain related to cash flow hedging instruments included in net income (loss)	0	(302)
Unrealized (loss) gains on marketable securities, available-for-sale:
Unrealized gains during the period	28	794
Less: reclassification adjustments for (gains) losses included in net income (loss)	(152)	67
Total unrealized (loss) gain on marketable securities, available-for-sale	(124)	861
Other comprehensive (loss) income before tax	(124)	559
Income tax benefit related to items of other comprehensive (loss) income	0	115
Other comprehensive (loss) income, net of tax	(124)	674
Comprehensive income (loss)	$ 21,993	$ (4,434)