Significant Accounting Policies - Computation of Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Jan. 27, 2019	Oct. 28, 2018	Jul. 29, 2018	Apr. 29, 2018	Jan. 28, 2018	Oct. 29, 2017	Jul. 30, 2017	Apr. 30, 2017	Jan. 27, 2019	Jan. 28, 2018	Jan. 29, 2017
Earnings Per Share, Basic and Diluted [Abstract]
Net income (loss)	$ 13,340	$ 12,165	$ 25,169	$ 12,382	$ (1,297)	$ 13,338	$ 12,564	$ 11,821	$ 63,056	$ 36,426	$ 54,661
Weighted average common shares outstanding - basic	65,525	66,014	66,063	66,324	66,310	66,194	65,763	65,839	65,982	66,027	65,427
Dilutive effect of share-based compensation									2,499	1,578	682
Weighted average common shares outstanding - diluted	68,165	68,731	68,880	68,195	66,310	67,817	67,470	67,376	68,481	67,605	66,109
Basic earnings (loss) per common share (in dollars per share)	$ 0.20	$ 0.18	$ 0.38	$ 0.19	$ (0.02)	$ 0.20	$ 0.19	$ 0.18	$ 0.96	$ 0.55	$ 0.84
Diluted earnings (loss) per common share (in dollars per share)	$ 0.20	$ 0.18	$ 0.37	$ 0.18	$ (0.02)	$ 0.20	$ 0.19	$ 0.18	$ 0.92	$ 0.54	$ 0.83
Anti-dilutive shares not included in the above calculations									553	402	1,111