CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Mar. 31, 2011
Statement of Comprehensive Income [Abstract]
Net income	$ 13,939	$ 69,228	$ 6,494
Other comprehensive income (loss), net of tax
Unrealized gain (loss) on investments in securities	22	15	(73)
Comprehensive income	$ 13,961	$ 69,243	$ 6,421