Senior Notes' Guarantor and Non-Guarantor Financial Information - Schedule of Condensed Consolidating Statements of Operations and Comprehensive Loss (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 27, 2014	Sep. 27, 2014	Jun. 28, 2014	Mar. 29, 2014	Dec. 28, 2013	Sep. 28, 2013	Jun. 29, 2013	Mar. 30, 2013	Dec. 27, 2014	Dec. 28, 2013	Dec. 29, 2012
Condensed Financial Statements, Captions [Line Items]
Total revenue	$ 334,086	$ 394,759	$ 324,295	$ 151,091	$ 238,267	$ 316,263	$ 254,842	$ 106,829	$ 1,204,231	$ 916,201	$ 926,254
Cost of revenue (excluding items shown separately below)									887,160	677,052	713,346
General and administrative expenses									159,286	145,990	129,203
Goodwill impairment										68,202
Depreciation, depletion, amortization and accretion									87,826	72,934	68,290
Operating (loss) income	23,307	47,749	33,922	(35,019)	(57,742)	37,895	13,731	(41,861)	69,959	(47,977)	15,415
Other (income) expense, net									(3,447)	1,378	8,287
Interest expense									86,742	56,443	58,079
(Loss) income from continuing operations before taxes									(13,336)	(105,798)	(50,951)
Income tax benefit									(6,983)	(2,647)	(3,920)
(Loss) income from continuing operations	4,753	28,110	13,832	(53,048)	(70,191)	22,950	244	(56,154)	(6,353)	(103,151)	(47,031)
(Income) loss from discontinued operations	285	(7)	(369)	20	271	160	(26)	123	(71)	528	3,546
Net (loss) income	4,468	28,117	14,201	(53,068)	(70,462)	22,790	270	(56,277)	(6,282)	(103,679)	(50,577)
Net income attributable to noncontrolling interest									2,495	3,112	1,919
Net (loss) income attributable to member of Summit Materials, LLC									(8,777)	(106,791)	(52,496)
Comprehensive (loss) income attributable to member of Summit Materials, LLC									(18,278)	(103,706)	(55,049)
Issuers [Member]
Condensed Financial Statements, Captions [Line Items]
General and administrative expenses									30,736
Depreciation, depletion, amortization and accretion									1,468
Operating (loss) income									(32,204)
Other (income) expense, net									(53,827)
Interest expense									31,827
(Loss) income from continuing operations before taxes									(10,204)
Income tax benefit									(1,427)
(Loss) income from continuing operations									(8,777)
Net (loss) income									(8,777)
Net (loss) income attributable to member of Summit Materials, LLC									(8,777)
Comprehensive (loss) income attributable to member of Summit Materials, LLC									(18,278)
Non-Wholly-Owned Guarantor [Member]
Condensed Financial Statements, Captions [Line Items]
Total revenue									94,402	80,759	81,516
Cost of revenue (excluding items shown separately below)									67,951	55,241	58,319
General and administrative expenses									6,763	7,673	6,235
Depreciation, depletion, amortization and accretion									14,500	11,378	10,093
Operating (loss) income									5,188	6,467	6,869
Other (income) expense, net									(14,444)	(3,737)	(2,065)
Interest expense									11,608	10,702	12,045
(Loss) income from continuing operations before taxes									8,024	(498)	(3,111)
(Loss) income from continuing operations									8,024	(498)	(3,111)
Net (loss) income									8,024	(498)	(3,111)
Net (loss) income attributable to member of Summit Materials, LLC									8,024	(498)	(3,111)
Comprehensive (loss) income attributable to member of Summit Materials, LLC									2,759	3,909	(6,759)
Wholly-Owned Guarantors [Member]
Condensed Financial Statements, Captions [Line Items]
Total revenue									1,065,590	807,921	824,796
Cost of revenue (excluding items shown separately below)									796,078	611,799	649,577
General and administrative expenses									119,250	129,768	121,633
Goodwill impairment										68,202
Depreciation, depletion, amortization and accretion									70,116	60,078	57,080
Operating (loss) income									80,146	(61,926)	(3,494)
Other (income) expense, net									(6,687)	(3,410)	6,630
Interest expense									51,248	49,591	47,293
(Loss) income from continuing operations before taxes									35,585	(108,107)	(57,417)
Income tax benefit									(5,766)	(2,647)	(3,925)
(Loss) income from continuing operations									41,351	(105,460)	(53,492)
(Income) loss from discontinued operations									(71)	528	3,546
Net (loss) income									41,422	(105,988)	(57,038)
Net (loss) income attributable to member of Summit Materials, LLC									41,422	(105,988)	(57,038)
Comprehensive (loss) income attributable to member of Summit Materials, LLC									41,422	(105,988)	(57,038)
Non-Guarantors [Member]
Condensed Financial Statements, Captions [Line Items]
Total revenue									72,172	41,910	33,074
Cost of revenue (excluding items shown separately below)									51,064	24,401	18,582
General and administrative expenses									2,537	1,308	1,327
Depreciation, depletion, amortization and accretion									1,742	1,013	1,036
Operating (loss) income									16,829	15,188	12,129
Other (income) expense, net									(3)	274	(101)
Interest expense									1,172	382	633
(Loss) income from continuing operations before taxes									15,660	14,532	11,597
Income tax benefit									210
(Loss) income from continuing operations									15,450	14,532	11,597
Net (loss) income									15,450	14,532	11,597
Net (loss) income attributable to member of Summit Materials, LLC									15,450	14,532	11,597
Comprehensive (loss) income attributable to member of Summit Materials, LLC									9,634	14,532	11,597
Eliminations [Member]
Condensed Financial Statements, Captions [Line Items]
Total revenue									(27,933)	(14,389)	(13,132)
Cost of revenue (excluding items shown separately below)									(27,933)	(14,389)	(13,132)
Other (income) expense, net									71,514	(90,834)	(48,577)
Interest expense									(9,113)	(4,232)	(1,892)
(Loss) income from continuing operations before taxes									(62,401)	95,066	50,469
(Loss) income from continuing operations									(62,401)	95,066	50,469
Net (loss) income									(62,401)	95,066	50,469
Net income attributable to noncontrolling interest									2,495	3,112	1,919
Net (loss) income attributable to member of Summit Materials, LLC									(64,896)	91,954	48,550
Comprehensive (loss) income attributable to member of Summit Materials, LLC									(53,815)	90,632	49,645
Summit Materials LLC (Parent) [Member]
Condensed Financial Statements, Captions [Line Items]
General and administrative expenses										7,241	8
Depreciation, depletion, amortization and accretion										465	81
Operating (loss) income										(7,706)	(89)
Other (income) expense, net										99,085	52,400
(Loss) income from continuing operations before taxes										(106,791)	(52,489)
Income tax benefit											5
(Loss) income from continuing operations										(106,791)	(52,494)
Net (loss) income										(106,791)	(52,494)
Net (loss) income attributable to member of Summit Materials, LLC										(106,791)	(52,494)
Comprehensive (loss) income attributable to member of Summit Materials, LLC										$ (106,791)	$ (52,494)