EARNINGS PER SHARE (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 26, 2020	Sep. 28, 2019	Sep. 26, 2020	Sep. 28, 2019
Weighted-average number of common and common equivalent shares outstanding:
Basic number of common shares outstanding	43,193,752	44,144,135	43,237,319	44,640,413
Dilutive effect of equity awards	156,878	287,904	174,351	302,832
Diluted number of common and common equivalent shares outstanding	43,350,630	44,432,039	43,411,670	44,943,245
Basic net income per common share (in thousands, except per share data):
Net income	$ 81,241	$ 60,252	$ 10,703	$ 138,655
Income allocated to participating securities	(837)	(565)	(88)	(1,244)
Net income available to common shareholders	$ 80,404	$ 59,687	$ 10,615	$ 137,411
Basic net income per common share (USD per share)	$ 1.86	$ 1.35	$ 0.25	$ 3.08
Diluted net income per common share (in thousands, except per share data):
Net income	$ 81,241	$ 60,252	$ 10,703	$ 138,655
Income allocated to participating securities	(834)	(563)	(89)	(1,239)
Net income available to common shareholders	$ 80,407	$ 59,689	$ 10,614	$ 137,416
Diluted net income per common share (USD per share)	$ 1.85	$ 1.34	$ 0.24	$ 3.06
Anti-dilutive awards excluded from diluted earnings per share computation (in shares)	729,476	691,707	744,499	505,642