CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Sales	$ 3,626,593	$ 3,682,448	$ 3,365,968
Cost of sales	2,675,289	2,773,232	2,570,453
Gross profit	951,304	909,216	795,515
Selling, general and administrative expenses	727,601	680,273	619,546
Depreciation expense	41,208	39,627	43,022
Amortization expense	18,045	15,015	16,003
Merger and integration costs	6,485	3,998	15,336
Impairment of assets	1,903	0	435
Total operating expenses	795,242	738,913	694,342
Income from operations	156,062	170,303	101,173
Other income (expense)
Interest expense	(23,156)	(24,035)	(25,036)
Other income, net	13,578	10,646	5,690
Income before income taxes	146,484	156,914	81,827
Income tax expense	36,639	37,176	24,402
Net income	$ 109,845	$ 119,738	$ 57,425
Weighted average common shares outstanding
Basic (in shares)	66,701	67,273	66,900
Diluted (in shares)	67,332	67,748	67,404
Net income per share
Basic (in dollars per share)	$ 1.65	$ 1.78	$ 0.86
Diluted (in dollars per share)	$ 1.63	$ 1.77	$ 0.85
Building products [Member]
Sales	$ 2,727,700	$ 2,856,700	$ 2,561,500
Construction services [Member]
Sales	$ 898,900	$ 825,800	$ 804,500