Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Total	Common Stock	Treasury Stock	Additional Paid in Capital	Accumulated Deficit	Accumulated Other Comprehensive (Loss) Income
Beginning Balance at Mar. 31, 2013	$ 137,080	$ 397	$ (16,129)	$ 414,810	$ (258,261)	$ (3,737)
Beginning Balance (in shares) at Mar. 31, 2013		38,601,384	1,186,999
Restricted stock issued		$ 3		(3)
Restricted stock issued (in shares)		254,991
Stock options exercised	9,360	$ 11		9,349
Stock options exercised (in shares)		1,029,024
Stock issued under employee stock purchase plan	697			697
Stock issued under employee stock purchase plan (in shares)		43,779
Stock issued to directors	65			65
Stock issued to directors (in shares)		6,518
Return of common stock to pay withholding taxes on restricted stock	(425)		$ (425)
Return of common stock to pay withholding taxes on restricted stock (in shares)		(19,368)	19,368
Stock compensation expense	11,218			11,218
Other comprehensive income (loss)	3,007					3,007
Net income	7,351				7,351
Ending Balance at Mar. 31, 2014	168,353	$ 411	$ (16,554)	436,136	(250,910)	(730)
Ending Balance (in shares) at Mar. 31, 2014		39,916,328	1,206,367
Restricted stock issued		$ 5		(5)
Restricted stock issued (in shares)		543,420
Stock options exercised	10,927	$ 9		10,918
Stock options exercised (in shares)		911,553
Stock issued under employee stock purchase plan	795			795
Stock issued under employee stock purchase plan (in shares)		39,095
Stock issued to directors	76			76
Stock issued to directors (in shares)		1,954
Return of common stock to pay withholding taxes on restricted stock	(2,805)	$ (12)	$ (2,793)
Return of common stock to pay withholding taxes on restricted stock (in shares)		(76,577)	76,577
Stock compensation expense	16,520			16,520
Excess tax benefit from stock-based awards	606			606
Other comprehensive income (loss)	(16,600)					(16,600)
Net income	113,688				113,688
Ending Balance at Mar. 31, 2015	$ 291,560	$ 413	$ (19,347)	465,046	(137,222)	(17,330)
Ending Balance (in shares) at Mar. 31, 2015	41,335,773	41,335,773	1,282,944
Restricted stock issued		$ 5		(5)
Restricted stock issued (in shares)		507,471
Stock options exercised	$ 9,771	$ 8		9,763
Stock options exercised (in shares)	829,000	829,385
Stock issued under employee stock purchase plan	$ 1,135			1,135
Stock issued under employee stock purchase plan (in shares)		16,772
Stock issued to directors	65			65
Stock issued to directors (in shares)		774
Return of common stock to pay withholding taxes on restricted stock	(7,313)		$ (7,313)
Return of common stock to pay withholding taxes on restricted stock (in shares)		(93,947)	93,947
Stock compensation expense	29,053			29,053
Excess tax benefit from stock-based awards	3,567			3,567
Other comprehensive income (loss)	2,790					2,790
Net income	38,147				38,147
Ending Balance at Mar. 31, 2016	$ 368,775	$ 426	$ (26,660)	$ 508,624	$ (99,075)	$ (14,540)
Ending Balance (in shares) at Mar. 31, 2016	42,596,228	42,596,228	1,376,891