Subsequent Events (Details) - Subsequent Event $ in Thousands		1 Months Ended
	Sep. 02, 2016 USD ($) location	Sep. 12, 2016 USD ($)
SKBM and OBS
Subsequent Events
Total purchase price	$ 75,627
Number of locations | location	4
Net sales generated by combined companies in previous twelve months	$ 99,724
Gypsum Supply Company
Subsequent Events
Decrease in deferred tax liabilities and tax expense for election to change tax treatment of acquisition from stock to asset transaction		$ 6,500