CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Sales	$ 3,682,448	$ 3,365,968	$ 3,093,743
Cost of sales	2,773,232	2,570,453	2,351,778
Gross profit	909,216	795,515	741,965
Selling, general and administrative expenses	680,273	619,546	571,799
Depreciation expense	39,627	43,022	38,441
Amortization expense	15,015	16,003	20,721
Merger and integration costs	3,998	15,336	15,340
Impairment of assets	0	435	11,928
Total operating expenses	738,913	694,342	658,229
Income from operations	170,303	101,173	83,736
Other income (expense)
Interest expense	(24,035)	(25,036)	(30,131)
Loss on debt extinguishment	0	0	(12,529)
Other income, net	10,646	5,690	4,070
Income before income taxes	156,914	81,827	45,146
Income tax expense	37,176	24,402	14,266
Net income	$ 119,738	$ 57,425	$ 30,880
Weighted average common shares outstanding
Basic (in shares)	67,273	66,900	66,055
Diluted (in shares)	67,748	67,404	66,609
Net income per share
Basic (in dollars per share)	$ 1.78	$ 0.86	$ 0.47
Diluted (in dollars per share)	$ 1.77	$ 0.85	$ 0.46
Building products [Member]
Sales	$ 2,856,683	$ 2,561,454	$ 2,336,041
Cost of sales	2,095,093	1,906,583	1,725,843
Construction services [Member]
Sales	825,765	804,514	757,702
Cost of sales	$ 678,139	$ 663,870	$ 625,935