QUARTERLY FINANCIAL DATA (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 26, 2020	Sep. 26, 2020	Jun. 27, 2020	Mar. 28, 2020	Dec. 28, 2019	Sep. 28, 2019	Jun. 29, 2019	Mar. 30, 2019	Dec. 26, 2020	Dec. 28, 2019	Dec. 29, 2018
Quarterly Financial Information Disclosure [Abstract]
Net sales	$ 798,377	$ 733,970	$ 688,808	$ 674,200	$ 683,626	$ 690,340	$ 700,871	$ 692,139	$ 2,895,355	$ 2,766,976	$ 2,757,144
Gross profit	204,581	190,747	183,937	186,249	166,591	173,287	178,176	164,627	765,514	682,681	668,172
Net earnings, amount	$ 35,815	$ 39,342	$ 22,607	$ 42,929	$ 32,540	$ 38,045	$ 39,719	$ 36,104	$ 140,693	$ 146,408	$ 101,770
Basic (in dollars per share)	$ 1.69	$ 1.85	$ 1.06	$ 2.00	$ 1.52	$ 1.76	$ 1.83	$ 1.65	$ 6.60	$ 6.76	$ 4.56
Diluted (in dollars per share)	1.68	1.84	1.06	1.99	1.51	1.75	1.82	1.64	6.57	6.73	$ 4.53
Stock Price, High (in dollars per share)	176.62	134.58	128.37	154.86	151.46	146.46	136.75	139.50	176.62	151.46
Stock Price, Low (in dollars per share)	119.88	108.15	98.93	82.60	123.80	123.74	112.94	107.43	82.60	107.43
Dividends Declared (in dollars per share)	$ 0.450	$ 0.450	$ 0.450	$ 0.450	$ 0.375	$ 0.375	$ 0.375	$ 0.375	$ 1.80	$ 1.50
Impairment of goodwill and intangible assets			$ 16,220						$ 16,638	$ 0	$ 15,780
Impairment of goodwill and intangible assets (in dollars per share)			$ 0.76
Restructuring charges	$ 11,041	$ 2,133	$ 4,019						$ 23,149
Restructuring expenses (in dollars per share)	$ 0.52	$ 0.10	$ 0.19