Consolidated Statements of Shareholders' Equity and Comprehensive Income (Loss) (USD $) In Thousands, unless otherwise specified	Total	Common Stock and Additional Paid-In Capital [Member]	Treasury Stock [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income [Member]
Balances at Mar. 31, 2009	$ 178,492	$ 177,912	$ (45,374)	$ 43,984	$ 1,970
Beginning balance, shares at Mar. 31, 2009		36,055	5,421
Comprehensive Income, net of tax:
Net income (loss)	(677)			(677)
Other comprehensive income (loss)	(90)				(90)
Total comprehensive income (loss)	(767)
Stock-based compensation	3,160	3,160
Proceeds from sale of shares through employee equity incentive plans, related excess tax benefits and others	2,538	2,538
Proceeds from sale of shares through employee equity incentive plans, related excess tax benefits and others, shares		742
Purchase of treasury stock	(288)		(288)
Purchase of treasury stock, shares			40
Balances at Mar. 31, 2010	183,135	183,610	(45,662)	43,307	1,880
Ending balance, shares at Mar. 31, 2010		36,797	5,461
Comprehensive Income, net of tax:
Net income (loss)	36,647			36,647
Other comprehensive income (loss)	5,883				5,883
Total comprehensive income (loss)	42,530
Stock-based compensation	3,398	3,398
Proceeds from sale of shares through employee equity incentive plans, related excess tax benefits and others	4,171	4,171
Proceeds from sale of shares through employee equity incentive plans, related excess tax benefits and others, shares		556
Purchase of treasury stock	(4,005)		(4,005)
Purchase of treasury stock, shares			439
Balances at Mar. 31, 2011	229,229	191,179	(49,667)	79,954	7,763
Ending balance, shares at Mar. 31, 2011		37,353	5,900
Comprehensive Income, net of tax:
Net income (loss)	30,306			30,306
Other comprehensive income (loss)	(5,673)				(5,673)
Total comprehensive income (loss)	24,633
Stock-based compensation	3,779	3,779
Proceeds from sale of shares through employee equity incentive plans, related excess tax benefits and others	3,703	3,703
Proceeds from sale of shares through employee equity incentive plans, related excess tax benefits and others, shares		453
Purchase of treasury stock	(7,576)		(7,576)
Purchase of treasury stock, shares			628
Re-issurance of treasury stock under stock compensation plans	339		405	(66)
Re-issuance of treasury stock under stock compensation plans, shares			(46)
Balances at Mar. 31, 2012	$ 254,107	$ 198,661	$ (56,838)	$ 110,194	$ 2,090
Ending balance, shares at Mar. 31, 2012		37,806	6,482