CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (UNAUDITED) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Net sales	$ 979,896	$ 946,375	$ 1,900,775	$ 1,771,780
Cost of sales	727,074	700,598	1,410,825	1,309,881
Gross profit	252,822	245,777	489,950	461,899
Selling, general and administrative expenses	173,420	181,431	360,342	351,365
Depreciation expense	11,704	10,043	23,223	19,616
Amortization expense	5,016	4,338	10,029	8,685
Asset Impairment Charges	2,255	529	2,255	529
Merger and integration costs	357	1,382	1,525	4,172
Total operating expenses	192,752	197,723	397,374	384,367
Income from operations	60,070	48,054	92,576	77,532
Other income (expense)
Interest expense	(6,204)	(5,574)	(12,136)	(11,612)
Other income, net	2,920	3,709	5,839	6,619
Income before income taxes	56,786	46,189	86,279	72,539
Income tax expense	13,164	10,490	20,628	16,490
Net income	$ 43,622	$ 35,699	$ 65,651	$ 56,049
Weighted average common shares outstanding
Basic (in shares)	67,022	66,578	66,931	66,679
Diluted (in shares)	67,564	67,077	67,604	67,179
Net income per common share
Basic (in dollars per share)	$ 0.65	$ 0.54	$ 0.98	$ 0.84
Diluted (in dollars per share)	$ 0.65	$ 0.53	$ 0.97	$ 0.83
Building Products [Member]
Net sales	$ 739,400	$ 712,400	$ 1,426,000	$ 1,333,300
Construction Services [Member]
Net sales	$ 240,500	$ 234,000	$ 474,700	$ 438,500