Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Property, plant and equipment, accumulated depreciation, depletion and amortization	$ 592,086	$ 484,554
Intangible assets, accumulated amortization	6,376	7,854
Valuation allowance	2,677	502,839
Summit Materials, LLC
Property, plant and equipment, accumulated depreciation, depletion and amortization	592,086	484,554
Intangible assets, accumulated amortization	$ 6,376	$ 7,854
Common Class A
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	1,000,000,000	1,000,000,000
Common stock, shares issued	108,465,688	96,033,222
Common stock, shares outstanding	108,465,688	96,033,222
Common Class B
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	250,000,000	250,000,000
Common stock, shares issued	100	100
Common stock, shares outstanding	100	100