Statement of Comprehensive Income (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2012	Dec. 31, 2011
Statement of Income and Comprehensive Income [Abstract]
Net income	$ 1,189	$ 5,671	$ 9,553	$ 26,594
Unrealized gain (loss) on available-for-sale investment securities, net of taxes of $(668) and $(444) for the three and nine months ended December 31, 2012 and net of taxes of $8 and $(40) for the three and nine months ended December 31, 2011	(1,241)	14	(825)	(75)
Foreign currency translation adjustments	2,321	(3,938)	(346)	(7,251)
Total comprehensive income	$ 2,269	$ 1,747	$ 8,382	$ 19,268