Computation of Earnings Per Common Share - Basic and Diluted Earnings Calculation (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Oct. 24, 2020	Oct. 26, 2019	Oct. 24, 2020	Oct. 26, 2019
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Net income available to common stockholders (numerator)	$ 33,926	$ 24,229	$ 38,532	$ 68,404
Weighted-average number of common shares (in shares)	31,878,583	31,502,543	31,744,199	31,480,759
Basic earnings per common share (in dollars per share)	$ 1.06	$ 0.77	$ 1.21	$ 2.17
Potential common stock arising from stock options, and unvested restricted share units (in shares)	546,717	324,302	362,462	330,746
Total shares-diluted (in shares)	32,425,300	31,826,845	32,106,661	31,811,505
Diluted earnings per common share (in dollars per share)	$ 1.05	$ 0.76	$ 1.20	$ 2.15
Anti-dilutive weighted shares excluded from the calculation of earnings per common share:
Anti-dilutive weighted shares excluded from the calculation of earnings per share (in shares)	1,440,924	10,251,008	4,477,819	10,267,737
Stock-based awards
Anti-dilutive weighted shares excluded from the calculation of earnings per common share:
Anti-dilutive weighted shares excluded from the calculation of earnings per share (in shares)	238,226	239,540	245,633	256,269
Convertible senior notes
Anti-dilutive weighted shares excluded from the calculation of earnings per common share:
Anti-dilutive weighted shares excluded from the calculation of earnings per share (in shares)	601,349	5,005,734	2,116,093	5,005,734
Note Warrant
Anti-dilutive weighted shares excluded from the calculation of earnings per common share:
Anti-dilutive weighted shares excluded from the calculation of earnings per share (in shares)	601,349	5,005,734	2,116,093	5,005,734