CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (USD $) In Thousands, unless otherwise specified	3 Months Ended		12 Months Ended
	Mar. 31, 2012	Mar. 31, 2011	Dec. 31, 2011
Net income	$ 90,092	$ 49,046	$ 363,261
Other comprehensive income:
Foreign currency translation	1,949	2,499	0
Change in unrealized gain on marketable debt securities	(308)	(1,257)	0
Other	223	(13)	0
Total other comprehensive income	1,864	1,229	(4,806)
Comprehensive income	91,956	50,275	0
Comprehensive (loss) income attributable to noncontrolling interest	(534)	62	0
Comprehensive income attributable to common stockholders	$ 92,490	$ 50,213	$ 0