Consolidated Statements of Stockholders' Equity (USD $) In Thousands	Total	Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Loss	Retained Earnings	Common Stock Held in Treasury
Beginning balance at Jan. 31, 2009	$ 162,229	$ 171	$ 99,486	$ 0	$ 63,542	$ (970)
Equity awards exercised/vested	1,188	2	1,186
Tax benefit from exercise/vesting of equity awards	859		859
Taxes paid for net share settlements	(296)		(296)
Amortization of share-based compensation	1,891		1,891
Shares issued in connection with public offering, net	34,657	19	34,638
Effect of exchange rate changes	(36)			(36)
Net income	31,718				31,718
Ending balance at Jan. 31, 2010	232,210	192	137,764	(36)	95,260	(970)
Equity awards exercised/vested	2,786	5	2,781
Tax benefit from exercise/vesting of equity awards	4,356		4,356
Amortization of share-based compensation	3,314		3,314
Stock warrants exercised	4,129	4	4,125
Effect of exchange rate changes	17			17
Net income	56,682				56,682
Ending balance at Jan. 31, 2011	303,494	201	152,340	(19)	151,942	(970)
Equity awards exercised/vested	619	2	617
Tax benefit from exercise/vesting of equity awards	1,945		1,945
Amortization of share-based compensation	5,200		5,200
Effect of exchange rate changes	23			23
Net income	49,620				49,620
Treasury share purchase	(2,929)					(2,929)
Ending balance at Jan. 31, 2012	$ 357,972	$ 203	$ 160,102	$ 4	$ 201,562	$ (3,899)