CONSOLIDATED STATEMENTS OF CHANGES IN NET ASSETS (Unaudited) (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Sep. 30, 2012	Sep. 30, 2011
Operations:
Net investment income/(loss)	$ (102)	$ 37
Net realized gain on investments	66,881	12,439
Net decrease in unrealized appreciation of investments	(28,200)	(48,634)
Increase (decrease) in net assets from operations	38,579	(36,158)
Distributions from:
Undistributed net investment income	(1,505)	(1,501)
Net realized gain distribution	(66,826)
Capital share transactions:
Exercise of employee stock options	3,017	98
Stock option expense	272	503
Decrease in net assets	(26,463)	(37,058)
Net assets, beginning of period	628,706	539,233
Net assets, end of period	$ 602,243	$ 502,175