Revenue Revenue (Disaggregation of Revenue) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Disaggregation of Revenue [Line Items]
Net sales	$ 834,202	$ 757,700
Single-family homebuilders [Member]
Disaggregation of Revenue [Line Items]
Net sales	637,308	559,589
Remodeling contractors [Member]
Disaggregation of Revenue [Line Items]
Net sales	95,451	82,075
Multi-family, commercial & other contractors [Member]
Disaggregation of Revenue [Line Items]
Net sales	101,443	116,036
Structural components [Member]
Disaggregation of Revenue [Line Items]
Net sales	135,829	109,891
Lumber & lumber sheet goods [Member]
Disaggregation of Revenue [Line Items]
Net sales	288,086	244,436
Millwork, doors & windows [Member]
Disaggregation of Revenue [Line Items]
Net sales	229,518	210,751
Other building products & services [Member]
Disaggregation of Revenue [Line Items]
Net sales	$ 180,769	$ 192,622