CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Common Stock [Member]	Additional Paid in Capital [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Retained Earnings [Member]
Balance (in shares) at Jan. 31, 2014		36,127,000
Balance at Jan. 31, 2014	$ 589,290	$ 361	$ 225,631	$ (100)	$ 363,398
Exercise of options and vesting of restricted stock, net of tax (in shares)		183,000
Exercise of options and vesting of restricted stock, net of tax	$ 600	$ 2	598
Issuance of common stock under Employee Stock Purchase Plan (in shares)	40,908	41,000
Issuance of common stock under Employee Stock Purchase Plan	$ 1,070	$ 1	1,069
Stock-based compensation	4,097		4,097
Net income (loss)	58,513				58,513
Change in fair value of hedges, net of tax of $55	100			100
Balance (in shares) at Jan. 31, 2015		36,351,000
Balance at Jan. 31, 2015	653,670	$ 364	231,395	0	421,911
Exercise of options and vesting of restricted stock, net of tax (in shares)		195,000
Exercise of options and vesting of restricted stock, net of tax	$ (43)	$ 2	(45)
Issuance of common stock under Employee Stock Purchase Plan (in shares)	48,585	49,000
Issuance of common stock under Employee Stock Purchase Plan	$ 969		969
Repurchase of common stock (in shares)		(5,965,000)
Repurchase of common stock	(151,781)	$ (60)	(151,721)
Stock-based compensation	4,611		4,611
Net income (loss)	30,855				30,855
Balance (in shares) at Jan. 31, 2016		30,630,000
Balance at Jan. 31, 2016	538,281	$ 306	85,209	0	452,766
Exercise of options and vesting of restricted stock, net of tax (in shares)		231,000
Exercise of options and vesting of restricted stock, net of tax	$ (695)	$ 3	(698)
Issuance of common stock under Employee Stock Purchase Plan (in shares)	100,758	101,000
Issuance of common stock under Employee Stock Purchase Plan	$ 765	$ 1	764
Stock-based compensation	5,001		5,001
Net income (loss)	(25,562)				(25,562)
Balance (in shares) at Jan. 31, 2017		30,962,000
Balance at Jan. 31, 2017	$ 517,790	$ 310	$ 90,276	$ 0	$ 427,204