CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Jun. 30, 2012	Jun. 30, 2011
Net income	$ 78,710	$ 99,293
Change in net unrealized holding (loss) gain on available-for-sale securities	(142)	2,046
Change in deferred tax asset	4	(119)
Other comprehensive (loss) income	(138)	1,927
Total Comprehensive Income	$ 78,572	$ 101,220