Consolidated Statements Of Income - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Statement [Abstract]
Net sales	$ 2,796,166	$ 2,371,482	$ 2,475,807
Cost of sales	2,090,076	1,832,280	1,955,463
Gross profit	706,090	539,202	520,344
Selling, general and administrative expenses	483,156	338,992	321,556
Operating profit	222,934	200,210	198,788
Interest expense, net	13,453	8,796	6,436
Income before income taxes	209,481	191,414	192,352
Provision for income taxes	51,041	44,905	43,801
Net income	$ 158,440	$ 146,509	$ 148,551
Net income per common share:
Basic (in usd per share)	$ 6.30	$ 5.86	$ 5.90
Diluted (in usd per share)	$ 6.27	$ 5.84	$ 5.83
Weighted average common shares outstanding:
Basic (in shares)	25,134	24,998	25,178
Diluted (in shares)	25,255	25,093	25,463