Summit Materials (SUM) 10-K 28 Feb 17 2016 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2016	Feb. 27, 2017	Feb. 20, 2017	Jul. 02, 2016
Document Information [Line Items]
Entity Registrant Name	Summit Materials, Inc.
Entity Central Index Key	1,621,563
Document Type	10-K
Document Period End Date	Dec. 31, 2016
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Entity Current Reporting Status	Yes
Entity Filer Category	Large Accelerated Filer
Document Fiscal Year Focus	2,016
Document Fiscal Period Focus	FY
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Public Float				$ 1,300,000,000
Membership interests description	As of February 20, 2017, 100% of Summit Materials, LLC's outstanding limited liability company interests were held by Summit Materials Intermediate Holdings, LLC, its sole member and an indirect subsidiary of Summit Materials, Inc
Common Class A
Document Information [Line Items]
Entity Common Stock, Shares Outstanding			106,063,222
Common Class B
Document Information [Line Items]
Entity Common Stock, Shares Outstanding			100
Summit Materials, LLC
Document Information [Line Items]
Entity Registrant Name	Summit Materials, LLC
Entity Central Index Key	1,571,371
Document Type	10-K
Document Period End Date	Dec. 31, 2016
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Entity Current Reporting Status	Yes
Entity Filer Category	Non-accelerated Filer
Document Fiscal Year Focus	2,016
Document Fiscal Period Focus	FY
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Public Float	$ 0
Membership interests percentage		100.00%

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($)	Dec. 31, 2016	Jan. 02, 2016
Current assets:
Cash and cash equivalents	$ 143,392,000	$ 186,405,000
Accounts receivable, net	162,377,000	145,544,000
Costs and estimated earnings in excess of billings	7,450,000	5,690,000
Inventories	157,679,000	130,082,000
Other current assets	12,800,000	4,807,000
Total current assets	483,698,000	472,528,000
Property, plant and equipment, net	1,446,452,000	1,269,006,000
Goodwill	782,212,000	596,397,000
Intangible assets, net	17,989,000	15,005,000
Other assets	51,115,000	43,243,000
Total assets	2,781,466,000	2,396,179,000
Current liabilities:
Current portion of debt	6,500,000	6,500,000
Current portion of acquisition-related liabilities	24,162,000	20,584,000
Accounts payable	81,565,000	81,397,000
Accrued expenses	111,605,000	92,942,000
Billings in excess of costs and estimated earnings	15,456,000	13,081,000
Total current liabilities	239,288,000	214,504,000
Long-term debt	1,514,456,000	1,273,652,000
Acquisition-related liabilities	32,664,000	39,977,000
Other noncurrent liabilities	135,019,000	100,186,000
Total liabilities	1,921,427,000	1,628,319,000
Commitments and contingencies
Stockholders' equity / Member's interest
Additional paid-in capital	824,304,000	619,003,000
Accumulated (deficit) earnings	19,028,000	10,870,000
Accumulated other comprehensive loss	(2,249,000)	(2,795,000)
Stockholders' equity	842,044,000	628,265,000
Noncontrolling interest in consolidated subsidiaries	1,378,000	1,362,000
Noncontrolling interest in Summit Materials, Inc.	16,617,000	138,233,000
Total stockholders' equity	860,039,000	767,860,000
Total liabilities and stockholders' equity / member's interest	2,781,466,000	2,396,179,000
Common Class A
Stockholders' equity / Member's interest
Common stock	961,000	497,000
Common Class B
Stockholders' equity / Member's interest
Common stock		690,000
Summit Materials, LLC
Current assets:
Cash and cash equivalents	142,672,000	185,388,000
Accounts receivable, net	162,377,000	145,544,000
Costs and estimated earnings in excess of billings	7,450,000	5,690,000
Inventories	157,679,000	130,082,000
Other current assets	12,800,000	4,807,000
Total current assets	482,978,000	471,511,000
Property, plant and equipment, net	1,446,452,000	1,269,006,000
Goodwill	782,212,000	596,397,000
Intangible assets, net	17,989,000	15,005,000
Other assets	46,789,000	43,243,000
Total assets	2,776,420,000	2,395,162,000
Current liabilities:
Current portion of debt	6,500,000	6,500,000
Current portion of acquisition-related liabilities	21,663,000	18,084,000
Accounts payable	81,610,000	81,397,000
Accrued expenses	110,473,000	92,942,000
Billings in excess of costs and estimated earnings	15,456,000	13,081,000
Total current liabilities	235,702,000	212,004,000
Long-term debt	1,514,456,000	1,273,652,000
Acquisition-related liabilities	25,161,000	31,028,000
Other noncurrent liabilities	124,708,000	100,186,000
Total liabilities	1,900,027,000	1,616,870,000
Commitments and contingencies
Stockholders' equity / Member's interest
Member's equity	1,087,558,000	1,050,882,000
Accumulated (deficit) earnings	(185,099,000)	(245,486,000)
Accumulated other comprehensive loss	(27,444,000)	(28,466,000)
Member's interest	875,015,000	776,930,000
Noncontrolling interest	1,378,000	1,362,000
Total member's interest	876,393,000	778,292,000
Total liabilities and stockholders' equity / member's interest	$ 2,776,420,000	$ 2,395,162,000

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2016	Jan. 02, 2016
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	96,033,222	49,745,944
Common stock, shares outstanding	96,033,222	49,745,944
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	69,007,297
Common stock, shares outstanding	100	69,007,297

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Jan. 02, 2016	Dec. 27, 2014
Revenue:
Product	$ 1,223,008	$ 1,043,843	$ 806,280
Service	265,266	246,123	264,325
Net revenue	1,488,274	1,289,966	1,070,605
Delivery and subcontract revenue	137,789	142,331	133,626
Total revenue	1,626,063	1,432,297	1,204,231
Cost of revenue (excluding items shown separately below):
Product	751,697	676,457	566,986
Service	182,584	171,857	186,548
Net cost of revenue	934,281	848,314	753,534
Delivery and subcontract cost	137,789	142,331	133,626
Total cost of revenue	1,072,070	990,645	887,160
General and administrative expenses	243,862	177,769	150,732
Depreciation, depletion, amortization and accretion	149,300	119,723	87,826
Transaction costs	6,797	9,519	8,554
Operating income (loss)	154,034	134,641	69,959
Interest expense	97,536	84,629	86,742
Loss on debt financings		71,631
Tax receivable agreement expense	14,938
Other expense (income), net	733	(2,425)	(3,447)
Income (loss) from operations before taxes	40,827	(19,194)	(13,336)
Income tax benefit	(5,299)	(18,263)	(6,983)
Income (loss) from continuing operations	46,126	(931)	(6,353)
Income from discontinued operations		(2,415)	(71)
Net income (loss)	46,126	1,484	(6,282)
Net income (loss) attributable to noncontrolling interest in subsidiaries	16	(1,826)	2,495
Net income (loss) attributable to Summit Holdings	9,327	(24,408)	(8,777)
Net income (loss) attributable to Summit Materials, Inc. / member of Summit Materials, LLC	36,783	27,718
Summit Materials, LLC
Revenue:
Product	1,223,008	1,043,843	806,280
Service	265,266	246,123	264,325
Net revenue	1,488,274	1,289,966	1,070,605
Delivery and subcontract revenue	137,789	142,331	133,626
Total revenue	1,626,063	1,432,297	1,204,231
Cost of revenue (excluding items shown separately below):
Product	751,697	676,457	566,986
Service	182,584	171,857	186,548
Net cost of revenue	934,281	848,314	753,534
Delivery and subcontract cost	137,789	142,331	133,626
Total cost of revenue	1,072,070	990,645	887,160
General and administrative expenses	243,862	177,769	150,732
Depreciation, depletion, amortization and accretion	149,300	119,723	87,826
Transaction costs	6,797	9,519	8,554
Operating income (loss)	154,034	134,641	69,959
Interest expense	96,483	83,757	86,742
Loss on debt financings		71,631
Other expense (income), net	746	(2,425)	(3,447)
Income (loss) from operations before taxes	56,805	(18,322)	(13,336)
Income tax benefit	(5,282)	(18,263)	(6,983)
Income (loss) from continuing operations	62,087	(59)	(6,353)
Income from discontinued operations		(2,415)	(71)
Net income (loss)	62,087	2,356	(6,282)
Net income (loss) attributable to noncontrolling interest	16	(1,826)	2,495
Net income (loss) attributable to Summit Materials, Inc. / member of Summit Materials, LLC	$ 62,071	$ 4,182	$ (8,777)
Common Class A
Earnings per share of Class A common stock:
Basic	$ 0.53	$ 0.70
Diluted	$ 0.53	$ 0.51
Weighted average shares of Class A common stock:
Basic	68,833,986	39,367,381
Diluted	69,317,452	89,472,266

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Operations - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Jan. 02, 2016	Dec. 27, 2014
Net income (loss)	$ 46,126	$ 1,484	$ (6,282)
Other comprehensive income (loss):
Postretirement curtailment adjustment			(1,346)
Postretirement liability adjustment	426	2,123	(3,919)
Foreign currency translation adjustment	2,125	(14,099)	(5,816)
Loss on cash flow hedges	(1,529)	(944)
Other comprehensive income (loss)	1,022	(12,920)	(11,081)
Comprehensive income (loss)	47,148	(11,436)	(17,363)
Less comprehensive income (loss) attributable to the noncontrolling interest in consolidated subsidiaries	16	(1,826)	915
Less comprehensive income (loss) attributable Summit Holdings	9,803	(34,533)	(18,278)
Comprehensive income attributable to Summit Materials, Inc. / Summit Materials, LLC	37,329	24,923
Summit Materials, LLC
Net income (loss)	62,087	2,356	(6,282)
Other comprehensive income (loss):
Postretirement curtailment adjustment			(1,346)
Postretirement liability adjustment	426	2,123	(3,919)
Foreign currency translation adjustment	2,125	(14,099)	(5,816)
Loss on cash flow hedges	(1,529)	(944)
Other comprehensive income (loss)	1,022	(12,920)	(11,081)
Comprehensive income (loss)	63,109	(10,564)	(17,363)
Less comprehensive loss attributable to noncontrolling interest	16	(1,826)	915
Comprehensive income attributable to Summit Materials, Inc. / Summit Materials, LLC	$ 63,093	$ (8,738)	$ (18,278)

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Jan. 02, 2016	Dec. 27, 2014
Cash flow from operating activities:
Net income (loss)	$ 46,126	$ 1,484	$ (6,282)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation, depletion, amortization and accretion	160,633	125,019	95,463
Share-based compensation expense	49,940	19,899	2,235
Deferred income tax benefit	8,589	19,838	5,927
Net (gain) loss on asset disposals	(3,102)	(23,087)	6,500
Net gain on debt financings		(9,877)
Other	(1,282)	(1,629)	(957)
(Increase) decrease in operating assets, net of acquisitions:
Accounts receivable, net	2,511	3,852	(10,366)
Inventories	(10,297)	4,275	(3,735)
Costs and estimated earnings in excess of billings	(2,684)	6,604	1,359
Other current assets	(5,518)	11,438	(3,997)
Other assets	1,976	(1,369)	4,767
Increase (decrease) in operating liabilities, net of acquisitions:
Accounts payable	(5,751)	(4,241)	(6,455)
Accrued expenses	13,196	(14,354)	13,311
Billings in excess of costs and estimated earnings	700	1,313	(305)
Other liabilities	7,004	(1,286)	(6,373)
Net cash provided by (used in) operating activities	244,863	98,203	79,238
Cash flow from investing activities:
Acquisitions, net of cash acquired	(336,958)	(510,017)	(397,854)
Purchases of property, plant and equipment	(153,483)	(88,950)	(76,162)
Proceeds from the sale of property, plant and equipment	16,868	13,110	13,366
Other	2,921	1,510	(630)
Net cash used for investing activities	(470,652)	(584,347)	(461,280)
Cash flow from financing activities:
Proceeds from equity offerings		1,037,444
Capital contributions by partner			24,350
Capital issuance costs	(136)	(61,609)
Proceeds from debt issuances	354,000	1,748,875	762,250
Debt issuance costs	(5,801)	(14,246)	(9,085)
Payments on debt	(120,702)	(1,505,486)	(389,270)
Purchase of noncontrolling interests		(497,848)
Payments on acquisition-related liabilities	(32,040)	(18,056)	(10,935)
Distributions from partnership	(13,034)	(28,736)
Other	420	(1)	(88)
Net cash provided by financing activities	182,707	660,337	377,222
Impact of cash on foreign currency	69	(1,003)	(149)
Net (decrease) increase in cash	(43,013)	173,190	(4,969)
Cash and cash equivalents-beginning of period	186,405	13,215	18,184
Cash and cash equivalents-end of period	143,392	186,405	13,215
Summit Materials, LLC
Cash flow from operating activities:
Net income (loss)	62,087	2,356	(6,282)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation, depletion, amortization and accretion	159,579	124,147	95,463
Share-based compensation expense	49,940	19,899	2,235
Deferred income tax benefit	(8,572)	(19,838)	(5,927)
Net (gain) loss on asset disposals	(3,102)	(23,087)	6,500
Goodwill impairment	0
Net gain on debt financings		(9,877)
Other	(1,282)	(1,629)	(957)
(Increase) decrease in operating assets, net of acquisitions:
Accounts receivable, net	2,511	3,852	(10,366)
Inventories	(10,297)	4,275	(3,735)
Costs and estimated earnings in excess of billings	(2,684)	6,604	1,359
Other current assets	(5,518)	11,438	(3,997)
Other assets	1,976	(1,369)	4,767
Increase (decrease) in operating liabilities, net of acquisitions:
Accounts payable	(5,706)	(4,241)	(6,455)
Accrued expenses	12,064	(14,354)	13,311
Billings in excess of costs and estimated earnings	700	1,313	(305)
Other liabilities	(6,819)	(1,286)	(6,373)
Net cash provided by (used in) operating activities	244,877	98,203	79,238
Cash flow from investing activities:
Acquisitions, net of cash acquired	(336,958)	(510,017)	(397,854)
Purchases of property, plant and equipment	(153,483)	(88,950)	(76,162)
Proceeds from the sale of property, plant and equipment	16,868	13,110	13,366
Other	2,921	1,510	(630)
Net cash used for investing activities	(470,652)	(584,347)	(461,280)
Cash flow from financing activities:
Capital contributions by partner	27,377	507,766	27,617
Capital issuance costs	(136)	(12,930)
Proceeds from debt issuances	354,000	1,748,875	762,250
Debt issuance costs	(5,801)	(14,246)	(9,085)
Payments on debt	(120,702)	(1,505,486)	(389,270)
Payments on acquisition-related liabilities	(29,540)	(18,056)	(10,935)
Distributions from partnership	(42,192)	(46,603)
Other	(16)		(88)
Net cash provided by financing activities	182,990	659,320	380,489
Impact of cash on foreign currency	69	(1,003)	(149)
Net (decrease) increase in cash	(42,716)	172,173	(1,702)
Cash and cash equivalents-beginning of period	185,388	13,215	14,917
Cash and cash equivalents-end of period	$ 142,672	$ 185,388	$ 13,215

Consolidated Statements of Chan

Consolidated Statements of Changes in Stockholders' Equity / Member's Interest and Redeemable Noncontrolling Interest - USD ($)	Summit Materials, LLCRedeemable Noncontrolling Interest	Summit Materials, LLCMembers' equity	Summit Materials, LLCTotal Member's Interest	Summit Materials, LLCNoncontrolling Interest in subsidiaries	Summit Materials, LLCAccumulated Earnings/Deficit	Summit Materials, LLCAccumulated Other Comprehensive Operations	Summit Materials, LLC	Redeemable Noncontrolling Interest	Partners' Interest	Noncontrolling Interest in subsidiaries	Accumulated Earnings/Deficit	Accumulated Other Comprehensive Operations	Common StockCommon Class A	Common StockCommon Class B	Additional Paid-in CapitalCommon Class B	Additional Paid-in Capital	Noncontrolling Interest in Summit Inc.	Common Class A	Common Class B	Total
Beginning Balance at Dec. 28, 2013	$ 24,767,000							$ 24,767,000
Increase (decrease) in redeemable noncontrolling interest
Accretion/ redemption value adjustment	8,145,000
Accretion/ redemption value adjustment								8,145,000
Net income (loss)	2,408,000							2,408,000
Other comprehensive income (loss)	(1,580,000)							(1,580,000)
Ending Balance at Dec. 27, 2014	33,740,000							33,740,000
Beginning Balance at Dec. 28, 2013									$ 285,606,000	$ 1,211,000										$ 286,817,000
Beginning Balance at Dec. 28, 2013		$ 486,896,000	$ 283,551,000	$ 1,211,000	$ (198,511,000)	$ (6,045,000)
Increase (decrease) in stockholders' equity / members' interest and redeemable noncontrolling interest
Contributed capital									24,351,000											24,351,000
Net contributed capital		27,617,000	27,617,000
Accretion/ redemption value adjustment			(8,145,000)		(8,145,000)				(8,145,000)											(8,145,000)
Net income (loss)			(8,690,000)	87,000	(8,777,000)		$ (6,282,000)													(6,282,000)
Net income (loss)									(8,777,000)	87,000										(8,690,000)
Other comprehensive income (loss)			(9,501,000)			(9,501,000)	(11,081,000)													(11,081,000)
Other comprehensive income (loss)									(9,501,000)											(9,501,000)
Share-based compensation		4,222,000	2,239,000		(1,983,000)				2,239,000											2,239,000
Repurchase of member's interest		(88,000)	(88,000)						(88,000)											(88,000)
Ending Balance at Dec. 27, 2014		518,647,000	286,983,000	1,298,000	(217,416,000)	(15,546,000)
Ending Balance at Dec. 27, 2014									285,685,000	1,298,000										286,983,000
Increase (decrease) in redeemable noncontrolling interest
Accretion/ redemption value adjustment								32,252,000
Net income (loss)								(1,890,000)
Ending Balance at Mar. 11, 2015								64,102,000
Increase (decrease) in stockholders' equity / members' interest and redeemable noncontrolling interest
Accretion/ redemption value adjustment									(32,252,000)											(32,252,000)
Net income (loss)									(41,338,000)	(77,000)										(41,415,000)
Other comprehensive income (loss)									(5,249,000)											(5,249,000)
Share-based compensation									424,000											424,000
Ending Balance at Mar. 11, 2015									207,270,000	1,221,000										208,491,000
Beginning Balance at Dec. 27, 2014	33,740,000							33,740,000
Increase (decrease) in redeemable noncontrolling interest
Accretion/ redemption value adjustment	(31,850,000)
Net income (loss)	$ (1,890,000)
Beginning Balance at Dec. 27, 2014									285,685,000	1,298,000										286,983,000
Beginning Balance at Dec. 27, 2014		518,647,000	286,983,000	1,298,000	(217,416,000)	(15,546,000)
Increase (decrease) in stockholders' equity / members' interest and redeemable noncontrolling interest
Net contributed capital		558,939,000	558,939,000
Accretion/ redemption value adjustment			(32,252,000)		(32,252,000)
Net income (loss)			4,246,000	64,000	4,182,000		2,356,000													1,484,000
Other comprehensive income (loss)			(12,920,000)			(12,920,000)	(12,920,000)													(12,920,000)
Share-based compensation		19,899,000	19,899,000
Distributions		(46,603,000)	(46,603,000)
Ending Balance at Jan. 02, 2016										1,362,000	$ 10,870,000	$ (2,795,000)	$ 497,000	$ 690,000		$ 619,003,000	$ 138,233,000			767,860,000
Ending Balance at Jan. 02, 2016		1,050,882,000	778,292,000	1,362,000	(245,486,000)	(28,466,000)	778,292,000
Ending Balance (in shares) at Jan. 02, 2016													49,745,944	69,007,297				49,745,944	69,007,297
Beginning Balance at Mar. 11, 2015								64,102,000
Increase (decrease) in redeemable noncontrolling interest
Purchase of redeemable noncontrolling interest								$ (64,102,000)
Beginning Balance at Mar. 11, 2015									207,270,000	1,221,000										208,491,000
Increase (decrease) in stockholders' equity / members' interest and redeemable noncontrolling interest
Recording of noncontrolling interest upon reorganization									$ (207,270,000)								207,270,000
Net income (loss)										141,000	27,718,000						16,930,000			44,789,000
Issuance of Shares													$ 480,000	$ 690,000	$ (690,000)	512,508,000				512,988,000
Issuance of Shares (in shares)													47,981,653	69,007,397
Other comprehensive income (loss)												(2,795,000)					(4,876,000)			(7,671,000)
Share-based compensation																19,475,000				19,475,000
Share repurchase																1,040,000	(1,040,000)
Share repurchase (in shares)														(100)
Purchase of noncontrolling interests																51,315,000	(51,315,000)
Purchase of redeemable noncontrolling interests (in shares)													1,029,183
Purchase of redeemable noncontrolling interests													$ 10,000			18,515,000				18,525,000
Distributions from partnership																	(28,736,000)			(28,736,000)
Dividend											(16,848,000)		$ 7,000			16,840,000				(1,000)
Dividend (in shares)													735,108
Ending Balance at Jan. 02, 2016										1,362,000	10,870,000	(2,795,000)	$ 497,000	$ 690,000		619,003,000	138,233,000			767,860,000
Ending Balance at Jan. 02, 2016		1,050,882,000	778,292,000	1,362,000	(245,486,000)	(28,466,000)	778,292,000
Ending Balance (in shares) at Jan. 02, 2016													49,745,944	69,007,297				49,745,944	69,007,297
Increase (decrease) in stockholders' equity / members' interest and redeemable noncontrolling interest
Net contributed capital		27,260,000	27,260,000
Net income (loss)			62,087,000	16,000	62,071,000		62,087,000			16,000	36,783,000						9,327,000			46,126,000
LP Unit exchanges													$ 451,000			117,813,000	(118,264,000)
LP Unit exchanges (in shares)													45,124,528
Other comprehensive income (loss)			1,022,000			1,022,000	1,022,000					546,000					476,000			1,022,000
Share-based compensation		51,624,000	49,940,000		(1,684,000)						(1,684,000)					51,624,000				49,940,000
Class B share cancellation														$ (690,000)		690,000
Class B share cancellation (in shares)														(69,007,197)
Distributions		(42,192,000)	(42,192,000)
Distributions from partnership																	(13,034,000)			(13,034,000)
Other													$ 27,058			8,127,000				8,129,000
Other (in shares)													2,000
Other		(16,000)	(16,000)
Dividend											(26,941,000)		$ 11,000			27,047,000	(121,000)			(4,000)
Dividend (in shares)													1,135,692
Ending Balance at Dec. 31, 2016										$ 1,378,000	$ 19,028,000	$ (2,249,000)	$ 961,000			$ 824,304,000	$ 16,617,000			$ 860,039,000
Ending Balance at Dec. 31, 2016		$ 1,087,558,000	$ 876,393,000	$ 1,378,000	$ (185,099,000)	$ (27,444,000)	$ 876,393,000
Ending Balance (in shares) at Dec. 31, 2016													96,033,222	100				96,033,222	100

Summary of Organization and Sig

Summary of Organization and Significant Accounting Policies	12 Months Ended
	Dec. 31, 2016
Company Information
Summary of Organization and Significant Accounting Policies	SUMMIT MATERIALS, INC. AND SUBSIDIARIES NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (Dollars in tables in thousands, unless otherwise noted) (1) Summary of Organization and Significant Accounting Policies Summit Materials, Inc. (“Summit Inc.” and, together with its subsidiaries, the “Company”) is a vertically-integrated construction materials company. The Company is engaged in the production and sale of aggregates, cement, ready-mix concrete, asphalt paving mix and concrete products and owns and operates quarries, sand and gravel pits, two cement plants, cement distribution terminals, ready-mix concrete plants, asphalt plants and landfill sites. It is also engaged in paving and related services. The Company’s three operating and reporting segments are the West, East and Cement segments. Substantially all of the Company’s products and services are produced, consumed and performed outdoors, primarily in the spring, summer and fall. Seasonal changes and other weather-related conditions can affect the production and sales volumes of its products and delivery of services. Therefore, the financial results for any interim period are typically not indicative of the results expected for the full year. Furthermore, the Company’s sales and earnings are sensitive to national, regional and local economic conditions and to cyclical changes in construction spending, among other factors. On September 23, 2014, Summit Inc. was formed as a Delaware corporation to be a holding company. Its sole material asset is a controlling equity interest in Summit Materials Holdings L.P. (“Summit Holdings”). Pursuant to a reorganization into a holding company structure (the “Reorganization”) consummated in connection with Summit Inc.’s March 2015 initial public offering, Summit Inc. became a holding corporation operating and controlling all of the business and affairs of Summit Holdings and its subsidiaries and, through Summit Holdings, conducts its business. Equity Offerings —Summit Inc. commenced operations on March 11, 2015 upon the pricing of the initial public offering of its Class A common stock (“IPO”). Summit Inc. raised $433.0 million, net of underwriting discounts, through the issuance of 25,555,555 shares of Class A common stock at a public offering price of $18.00 per share. Summit Inc. used the offering proceeds to purchase a number of newly-issued Class A Units (“LP Units”) from Summit Holdings equal to the number of shares of Class A common stock issued to the public. Summit Inc. caused Summit Holdings to use these proceeds: (i) to redeem $288.2 million in aggregate principal amount of outstanding 10 1 / 2 % senior notes due January 31, 2020 (“2020 Notes”); (ii) to purchase 71,428,571 Class B Units of Continental Cement Company, L.L.C. (“Continental Cement”); (iii) to pay a one-time termination fee of $13.8 million in connection with the termination of a transaction and management fee agreement with Blackstone Capital Partners V L.P.; and (iv) for general corporate purposes. The $288.2 million redemption of 2020 Notes was completed at a redemption price equal to par plus an applicable premium of $38.2 million plus $5.2 million of accrued and unpaid interest. In connection with the IPO, Summit Inc. issued 69,007,297 shares of its Class B common stock to Summit Owner Holdco LLC (“Summit Owner Holdco”), a Delaware limited liability company owned by certain pre-IPO owners and the former holders of Class B Units of Continental Cement. The Class B common stock entitled Summit Owner Holdco, without regard to the number of shares of Class B common stock held by it, to a number of votes that is equal to the aggregate number of LP Units held by all limited partners of Summit Holdings (excluding Summit Inc.). On July 19, 2016, Summit Owner Holdco transferred 28,661,526 shares of its Class B common stock to certain holders of LP Units and the remaining 40,345,771 shares of Class B common stock were cancelled. The Class B common stock entitles holders thereof, who are also holders of LP Units, with a number of votes that is equal to the number of LP Units they hold. The Class B common stock does not participate in dividends and does not have any liquidation rights. On August 11, 2015, Summit Inc. raised $555.8 million, net of underwriting discounts, through the issuance of 22,425,000 shares of Class A common stock at a public offering price of $25.75 per share ("the August 2015 follow-on offering"). Summit Inc. used these proceeds to purchase 3,750,000 newly-issued LP Units from Summit Holdings and 18,675,000 LP Units from certain pre-IPO owners, at a purchase price per LP Unit equal to the public offering price per share of Class A common stock, less underwriting discounts and commissions. Summit Holdings used the proceeds from the 3,750,000 newly-issued LP Units to pay the deferred purchase price of $80.0 million related to the July 17, 2015 acquisition of a cement plant and quarry in Davenport, Iowa, and seven cement terminals along the Mississippi River (the “Davenport Assets”) and for general corporate purposes. Principles of Consolidation —The consolidated financial statements include the accounts of Summit Inc. and its majority owned subsidiaries. All intercompany balances and transactions have been eliminated. As a result of the Reorganization, Summit Holdings became a variable interest entity over which Summit Inc. has 100% voting power and control and for which Summit Inc. has the obligation to absorb losses and the right to receive benefits. As a result, Summit Inc. is Summit Holdings’ primary beneficiary and thus consolidates Summit Holdings in its consolidated financial statements with a corresponding noncontrolling interest elimination, which was 5.1% and 50.3% as of December 31, 2016 and January 2, 2016, respectively. Noncontrolling interests in consolidated subsidiaries represent a 20% ownership in Ohio Valley Asphalt, LLC and, prior to the IPO and concurrent purchase of the noncontrolling interests of Continental Cement, a 30% redeemable ownership in Continental Cement. The Company attributes consolidated stockholders’ equity and net income separately to the controlling and noncontrolling interests. The Company accounts for investments in entities for which it has an ownership of 20% to 50% using the equity method of accounting. The Company’s fiscal year is based on a 52-53 week year with each quarter composed of 13 weeks ending on a Saturday. The 53-week year occurs approximately once every seven years and occurred in 2015. The additional week in the 53-week year was included in the fourth quarter of 2015. Use of Estimates —Preparation of these consolidated financial statements in conformity with U.S. generally accepted accounting principles (“U.S. GAAP”) requires management to make estimates and assumptions. These estimates and the underlying assumptions affect the amounts of assets and liabilities reported, disclosures about contingent assets and liabilities and reported amounts of revenue and expenses. Such estimates include the valuation of accounts receivable, inventories, valuation of deferred tax assets, goodwill, intangibles and other long-lived assets, pension and other postretirement obligations, and asset retirement obligations. Estimates also include revenue earned on contracts and costs to complete contracts. Most of the Company’s paving and related services are performed under fixed unit-price contracts with state and local governmental entities. Management regularly evaluates its estimates and assumptions based on historical experience and other factors, including the current economic environment. As future events and their effects cannot be determined with precision, actual results can differ significantly from estimates made. Changes in estimates, including those resulting from continuing changes in the economic environment, are reflected in the Company’s consolidated financial statements when the change in estimate occurs. Business and Credit Concentrations— The Company’s operations are conducted primarily across 21 U.S. states and in British Columbia, Canada, with the most significant revenue generated in Texas, Kansas, Utah and Missouri . The Company’s accounts receivable consist primarily of amounts due from customers within these areas. Therefore, collection of these accounts is dependent on the economic conditions in the aforementioned states, as well as specific situations affecting individual customers. Credit granted within the Company’s trade areas has been granted to many customers and management does not believe that a significant concentration of credit exists with respect to any individual customer or group of customers. No single customer accounted for more than 10% of the Company’s total revenue in 2016, 2015 or 2014. Accounts Receivable —Accounts receivable are stated at the amount management expects to collect from outstanding balances. Management provides for probable uncollectible amounts through a charge to earnings and a credit to a valuation allowance based on its assessment of the collectability of individual accounts. In establishing the allowance, management considers historical losses adjusted to take into account current market conditions and its customers’ financial condition, the amount of receivables in dispute, the current receivables aging and current payment terms. Balances that remain outstanding after reasonable collection efforts are exercised are written off through a charge to the valuation allowance. The balances billed but not paid by customers, pursuant to retainage provisions included in contracts, are generally due upon completion of the contracts. Revenue and Cost Recognition —Revenue for product sales are recognized when evidence of an arrangement exists, the fee is fixed or determinable, title passes, which is generally when the product is shipped, and collection is reasonably assured. Product revenue includes sales of aggregates, cement and other materials to customers, net of discounts, allowances or taxes, as applicable. Revenue from construction contracts are included in service revenue and are recognized under the percentage-of-completion accounting method. The percent complete is measured by the cost incurred to date compared to the estimated total cost of each project. This method is used as management considers expended cost to be the best available measure of progress on these contracts, the majority of which are completed within one year, but may occasionally extend beyond one year. Inherent uncertainties in estimating costs make it at least reasonably possible that the estimates used will change within the near term and over the life of the contracts. Contract costs include all direct material and labor costs and those indirect costs related to contract performance and completion. Provisions for estimated losses on uncompleted contracts are made in the period in which such losses are estimable. General and administrative costs are charged to expense as incurred. Changes in job performance, job conditions and estimated profitability, including those arising from contract penalty provisions and final contract settlements, may result in revisions to costs and income. Such revisions are recognized in the period in which they are determined. An amount equal to contract costs incurred that are attributable to claims is included in revenue when realization is probable and the amount can be reliably estimated. Costs and estimated earnings in excess of billings are composed principally of revenue recognized on contracts (on the percentage-of-completion method) for which billings had not been presented to customers because the amount were not billable under the contract terms at the balance sheet date. In accordance with the contract terms, the unbilled receivables at December 31, 2016 will be billed in 2017. Billings in excess of costs and estimated earnings represent billings in excess of revenue recognized. Revenue from the receipt of waste fuels is classified as service revenue and is based on fees charged for the waste disposal, which are recognized when the waste is accepted. Inventories —Inventories consist of stone that has been removed from quarries and processed for future sale, cement, raw materials and finished concrete blocks. Inventories are valued at the lower of cost or market and are accounted for on a first-in first-out basis or an average cost basis. If items become obsolete or otherwise unusable or if quantities exceed what is projected to be sold within a reasonable period of time, they will be charged to costs of production in the period that the items are designated as obsolete or excess inventory. Stripping costs are costs of removing overburden and waste material to access aggregate materials and are recognized in cost of revenue in the same period as the revenue from the sale of the inventory. Property, Plant and Equipment, net —Property, plant and equipment are recorded at cost, less accumulated depreciation, depletion and amortization. Expenditures for additions and improvements that significantly add to the productive capacity or extend the useful life of an asset are capitalized. Repair and maintenance costs that do not substantially expand productive capacity or extend the life of property, plant and equipment are expensed as incurred. Landfill airspace is included in property, plant and equipment at cost and is amortized based on the portion of the airspace used during the period compared to the gross estimated value of available airspace, which is updated periodically as circumstances dictate. Management reassesses the landfill airspace capacity with any changes in value recorded in cost of revenue. Capitalized landfill costs include expenditures for the acquisition of land and related airspace, engineering and permitting costs, cell construction costs and direct site improvement costs. Upon disposal of an asset, the cost and related accumulated depreciation are removed from the Company’s accounts and any gain or loss is included in general and administrative expenses. Depreciation on property, plant and equipment, including assets subject to capital leases, is generally computed on a straight-line basis. Depletion of mineral reserves is computed based on the portion of the reserves used during the period compared to the gross estimated value of proven and probable reserves, which is updated periodically as circumstances dictate. Leasehold improvements are amortized on a straight-line basis over the lesser of the asset’s useful life or the remaining lease term. The estimated useful lives are generally as follows: Buildings and improvements 10 - 30 years Plant, machinery and equipment 15 - 20 years Office equipment 3 - 7 years Truck and auto fleet 5 - 8 years Mobile equipment and barges 6 - 8 years Landfill airspace and improvements 10 - 30 years Other 4 - 20 years The Company reviews the carrying value of property, plant and equipment for impairment whenever events or circumstances indicate that the carrying value of an asset may not be recoverable from the estimated future cash flows expected to result from its use and eventual disposition. Such indicators may include, among others, deterioration in general economic conditions, adverse changes in the markets in which an entity operates, increases in input costs that have a negative effect on earnings and cash flows or a trend of negative or declining cash flows over multiple periods. Property, plant and equipment is tested for impairment at the lowest level for which identifiable cash flows are largely independent of the cash flows of other assets. As a result, the property, plant and equipment impairment test is at a significantly lower level than the level at which goodwill is tested for impairment. In markets where the Company does not produce downstream products, such as ready-mix concrete, asphalt paving mix and paving and related services, the lowest level of largely independent identifiable cash flows is at the individual aggregates operation or a group of aggregates operations collectively serving a local market or the cement operations. Conversely, in vertically-integrated markets, the cash flows of the downstream and upstream businesses are not largely independently identifiable and the vertically-integrated operations are considered the lowest level of largely independent identifiable cash flows. Assets are assessed for impairment charges when identified for disposition. Projected losses from disposition are recognized in the period in which they become estimable, which may be in advance of the actual disposition. The net gain (loss) from asset dispositions recognized in general and administrative expenses in fiscal years 2016, 2015 and 2014 was $6.8 million, $23.5 million and ($2.6 million), respectively. No material impairment charges have been recognized on assets held for use in 2016, 2015 or 2014. The losses are commonly a result of the cash flows expected from selling the asset being less than the expected cash flows that could be generated from holding the asset for use. Accrued Mining and Landfill Reclamation —The mining reclamation reserve and financial commitments for landfill closure and post-closure activities are based on management’s estimate of future cost requirements to reclaim property at both currently operating and closed sites. Estimates of these obligations have been developed based on management’s interpretation of current requirements and proposed regulatory changes and are intended to approximate fair value. Costs are estimated in current dollars, inflated until the expected time of payment, using an inflation rate of 2.5%, and then discounted back to present value using a credit-adjusted, risk-free rate on obligations of similar maturity, adjusted to reflect the Company’s credit rating. Changes in the credit-adjusted, risk-free rate do not change recorded liabilities. However, subsequent increases in the recognized obligations are measured using a current credit-adjusted, risk-free rate. Decreases in the recognized obligations are measured at the initial credit-adjusted, risk-free rate. Significant changes in inflation rates or the amount or timing of future cost estimates typically result in both (1) a current adjustment to the recorded liability (and corresponding adjustment to the asset) and (2) a change in accretion of the liability and depreciation of the asset to be recorded prospectively over the remaining capacity of the unmined quarry or landfill. Intangible Assets —The Company’s intangible assets are primarily composed of lease agreements and reserve rights. The assets related to lease agreements reflect the submarket royalty rates paid under agreements, primarily, for extracting aggregates. The values were determined as of the respective acquisition dates by a comparison of market-royalty rates to contract-royalty rates. The reserve rights relate to aggregate reserves to which the Company has the rights of ownership, but do not own the reserves. The intangible assets are amortized on a straight-line basis over the lives of the leases. The following table shows intangible assets by type and in total: December 31, 2016 January 2, 2016 Gross Net Gross Net Carrying Accumulated Carrying Carrying Accumulated Carrying Amount Amortization Amount Amount Amortization Amount Leases $ $ $ $ $ $ Reserve rights Trade names Other Total intangible assets $ $ $ $ $ $ Amortization expense in 2016, 2015 and 2014 was $2.6 million, $2.2 million and $0.9 million, respectively. The estimated amortization expense for intangible assets for each of the next five years and thereafter is as follows: 2017 $ 2018 2019 2020 2021 Thereafter Total $ Goodwill —Goodwill represents the purchase price paid in excess of the fair value of net tangible and intangible assets acquired. Goodwill recorded in connection with the Company’s acquisitions is primarily attributable to the expected profitability, assembled workforces of the acquired businesses and the synergies expected to arise after the Company’s acquisition of those businesses. Goodwill is not amortized, but is tested annually for impairment as of the first day of the fourth quarter and at any time that events or circumstances indicate that goodwill may be impaired. A qualitative approach may first be applied to determine whether it is more likely than not that the estimated fair value of a reporting unit is less than its carrying amount. If, as a result of the qualitative assessment, it is determined that an impairment is more likely than not, the two-step quantitative impairment test is then performed, otherwise further analysis is not required. The two-step impairment test first identifies potential goodwill impairment for each reporting unit and then, if necessary, measures the amount of the impairment loss. Income Taxes —Summit Inc. is a corporation subject to income taxes in the United States. Certain subsidiaries, including Summit Holdings, or subsidiary groups of the Company are taxable separate from Summit Inc. The provisions, or Summit Inc.’s proportional share of the provision, are included in the Company’s consolidated financial statements. The Company’s deferred income tax assets and liabilities are computed for differences between the tax basis and financial statement amounts that will result in taxable or deductible amounts in the future. The computed deferred balances are based on enacted tax laws and applicable rates for the periods in which the differences are expected to affect taxable income. A valuation allowance is recognized for deferred tax assets if it is more likely than not that some portion or all of the net deferred tax assets will not be realized. In making such a determination, all available positive and negative evidence is considered, including future reversals of existing taxable temporary differences, projected future taxable income, tax-planning strategies, and results of recent operations. If the Company determines it would be able to realize its deferred tax assets for which a valuation allowance had been recorded then an adjustment would be made to the deferred tax asset valuation allowance, which would reduce the provision for income taxes. The Company evaluates the tax positions taken on income tax returns that remain open and positions expected to be taken on the current year tax returns to identify uncertain tax positions. Unrecognized tax benefits on uncertain tax positions are recorded on the basis of a two-step process in which (1) the Company determines whether it is more likely than not that the tax positions will be sustained on the basis of the technical merits of the position and (2) for those tax positions that meet the more-likely-than-not recognition threshold, the largest amount of tax benefit that is more than 50 percent likely to be realized is recognized. Interest and penalties related to unrecognized tax benefits are recorded in income tax expense. Earnings per Share— The Company computes basic earnings per share attributable to stockholders by dividing income attributable to Summit Inc. by the weighted-average shares of Class A common stock outstanding. Diluted earnings per share reflects the potential dilution beyond shares for basic earnings per share that could occur if securities or other contracts to issue common stock were exercised, converted into common stock, or resulted in the issuance of common stock that would have shared in the Company’s earnings. Since the Class B common stock has no economic value, those shares are not included in the weighted-average common share amount for basic or diluted earnings per share. In addition, as the shares of Class A common stock are issued by Summit Inc., the earnings and equity interests of noncontrolling interests are not included in basic earnings per share. Fair Value Measurements— Certain acquisitions made by the Company require the payment of contingent amounts of purchase consideration. These payments are contingent on specified operating results being achieved in periods subsequent to the acquisition and will only be made if earn-out thresholds are achieved. Contingent consideration obligations are measured at fair value each reporting period. Any adjustments to fair value are recognized in earnings in the period identified. The Company has entered into interest rate derivatives on $200.0 million of its term loan borrowings to add stability to interest expense and to manage its exposure to interest rate movements. The effective portion of changes in the fair value of derivatives designated and that qualify as cash flow hedges is recorded in accumulated other comprehensive income and will be subsequently reclassified into earnings in the period that the hedged forecasted transaction affects earnings. The fair value of contingent consideration and derivatives as of December 31, 2016 and January 2, 2016 was: 2016 2015 Current portion of acquisition-related liabilities and Accrued expenses: Contingent consideration $ $ Cash flow hedges Acquisition-related liabilities and Other noncurrent liabilities Contingent consideration $ $ Cash flow hedges The fair value accounting guidance establishes the following fair value hierarchy that prioritizes the inputs used to measure fair value: Level 1 — Unadjusted quoted prices for identical assets or liabilities in active markets. Level 2 — Inputs other than Level 1 that are based on observable market data, either directly or indirectly. These include quoted prices for similar assets or liabilities in active markets, quoted prices for identical assets or liabilities in inactive markets, inputs that are observable that are not prices and inputs that are derived from or corroborated by observable markets. Level 3 — Valuations developed from unobservable data, reflecting the Company’s own assumptions, which market participants would use in pricing the asset or liability. The fair value of contingent consideration was based on unobservable, or Level 3, inputs, including projected probability-weighted cash payments and an 11.0% discount rate, which reflects a market discount rate. Changes in fair value may occur as a result of a change in actual or projected cash payments, the probability weightings applied by the Company to projected payments or a change in the discount rate. Significant increases or decreases in any of these inputs in isolation could result in a lower, or higher, fair value measurement. The fair value of the cash flow hedges are based on observable, or Level 2, inputs such as interest rates, bond yields and prices in inactive markets. There were no material adjustments to the fair value of contingent consideration in 2015 or to cash flow hedges in 2016 or 2015. In 2016, a $6.1 million increase in the fair value of contingent consideration was recognized as a result of a change in projected cash payments. Financial Instruments —The Company’s financial instruments include debt and certain acquisition-related liabilities (deferred consideration and noncompete obligations). The carrying value and fair value of these financial instruments as of December 31, 2016 and January 2, 2016 were: December 31, 2016 January 2, 2016 Fair Value Carrying Value Fair Value Carrying Value Level 2 Long-term debt(1) $ $ $ $ Level 3 Current portion of deferred consideration and noncompete obligations(2) Long term portion of deferred consideration and noncompete obligations(3) (1) $6.5 million included in current portion of debt as of December 31, 2016 and January 2, 2016. (2) Included in current portion of acquisition-related liabilities on the consolidated balance sheets. (3) Included in acquisition-related liabilities on the consolidated balance sheets. The fair value of debt was determined based on observable, or Level 2 inputs, such as interest rates, bond yields and quoted prices in inactive markets. The fair values of the deferred consideration and noncompete obligations were determined based on unobservable, or Level 3, inputs, including the cash payment terms in the purchase agreements and a discount rate reflecting the Company’s credit risk. The discount rate used is generally consistent with that used when the obligations were initially recorded. Securities with a maturity of three months or less are considered cash equivalents and the fair value of these assets approximates their carrying value. New Accounting Standards — In January 2017, the Financial Accounting Standards Board (“FASB”) issued a new Accounting Standards Update (“ASU”) 2017-04 Intangibles - Goodwill and Other (Topic 350) , which simplifies the test for goodwill impairment. The ASU eliminates the two step goodwill impairment test and replaces it with a single step test. The single step test compares the carrying amount of a reporting unit to its fair value; if the carrying amount is greater than the fair value the difference is the amount of the goodwill impairment. Step zero is left unchanged. Therefore, entities that wish do a qualitative assessment are still permitted to do so. The ASU is effective for SEC filers for fiscal years beginning after December 15, 2020. However, the Company will early adopt this ASU as of the beginning of fiscal year 2017. In March 2016, the FASB issued a new accounting standard with targeted amendments to the accounting for employee share-based payments. ASU 2016-09, Improvements to Employee Share-Based Payment Accounting , requires that the income tax effect of share-based awards be recognized in the income statement and allows entities to elect an accounting method to recognize forfeitures as they occur or to estimate forfeitures, as is currently required. The ASU is effective for public entities for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2016. However, the Company early adopted this ASU as of the beginning of fiscal year 2016 and made an election to recognize forfeitures as they occur. The ASU adoption was applied using a modified retrospective method by means of a $1.7 million cumulative-effect adjustment to accumulated earnings as of the beginning of the fiscal year. In February 2016, the FASB issued a new accounting standard related to lease accounting, ASU No. 2016-02, Leases , which will result in lessees recognizing most leases on the balance sheet. Lessees are required to disclose more quantitative and qualitative information about their leases than current U.S. GAAP requires. The ASU is effective for public entities for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2018. As of December 31, 2016 and January 2, 2016, the Company’s undiscounted minimum contractual commitments under long-term operating leases, which were not recorded on the balance sheet, were $31.3 million and $21.9 million, respectively, which is an estimate of the effect to lease obligations and property, plant and equipment that the new accounting standard would have as of the dates noted prior to the effect of discounting. In May 2014, the FASB issued a new accounting standard to improve and converge the financial reporting requirements for revenue from contracts with customers. ASU No. 2014-09, Revenue from Contracts with Customers , prescribes a five-step model for revenue recognition that will replace most existing revenue recognition guidance in U.S. GAAP. The ASU will supersede nearly all existing revenue recognition guidance under U.S. GAAP and provides that an entity recognize revenue when it transfers promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. This update also requires additional disclosure about the nature, amount, timing and uncertainty of revenue and cash flows arising from customer contracts, including significant judgments and changes in judgments, and assets recognized from costs incurred to obtain or fulfill a contract. ASU No. 2014-09 allows for either full retrospective or modified retrospective adoption. In July 2015, the FASB postponed the effective date of the new revenue standard by one year to the first quarter of 2018. Early adoption is permitted, but no earlier than 2017. In 2016, the Company established an implementation team (“team”) and engaged external advisers to develop a multi-phase plan to assess the Company’s business and contracts, as well as any changes to processes or systems to adopt the requirements of the new standard. The team has updated the assessment for new ASU updates and for newly acquired businesses. The team is in the process of developing it
Summit Materials, LLC
Company Information
Summary of Organization and Significant Accounting Policies	(1) Summary of Organization and Significant Accounting Policies Summit Materials, LLC (“Summit LLC” and, together with its subsidiaries, the “Company”) is a vertically integrated, construction materials company. The Company is engaged in the production and sale of aggregates, cement, ready-mix concrete, asphalt paving mix and concrete products and owns and operates quarries, sand and gravel pits, two cement plants, cement distribution terminals, ready-mix concrete plants, asphalt plants and landfill sites. It is also engaged in paving and related services. The Company’s three operating and reporting segments are the West, East and Cement segments. Substantially all of the Company’s products and services are produced, consumed and performed outdoors, primarily in the spring, summer and fall. Seasonal changes and other weather-related conditions can affect the production and sales volumes of its products and delivery of services. Therefore, the financial results for any interim period are typically not indicative of the results expected for the full year. Furthermore, the Company’s sales and earnings are sensitive to national, regional and local economic conditions and to cyclical changes in construction spending, among other factors. Summit LLC is a wholly owned indirect subsidiary of Summit Materials Holdings L.P. (“Summit Holdings”), whose primary owner is Summit Materials, Inc. (“Summit Inc.”). Summit Inc. was formed as a Delaware corporation on September 23, 2014. Its sole material asset is a controlling equity interest in Summit Holdings. Pursuant to a reorganization into a holding company structure (the “Reorganization”) in connection with Summit Inc.’s March 2015 initial public offering, Summit Inc. became a holding corporation operating and controlling all of the business and affairs of Summit Holdings and its subsidiaries, including Summit LLC. Summit Inc.’s Equity Offerings — Summit Inc. commenced operations on March 11, 2015 upon the pricing of the initial public offering of its Class A common stock (“IPO”). Summit Inc. raised $433.0 million, net of underwriting discounts, through the issuance of 25,555,555 shares of Class A common stock at a public offering price of $18.00 per share. Summit Inc. used the offering proceeds to purchase a number of newly-issued Class A Units (“LP Units”) from Summit Holdings equal to the number of shares of Class A common stock issued to the public. Summit Inc. caused Summit Holdings to use these proceeds: (i) to redeem $288.2 million in aggregate principal amount of outstanding 10 1 / 2 % senior notes due January 31, 2020 (“2020 Notes”); (ii) to purchase 71,428,571 Class B Units of Continental Cement Company, L.L.C. (“Continental Cement”); (iii) to pay a one-time termination fee of $13.8 million in connection with the termination of a transaction and management fee agreement with Blackstone Capital Partners V L.P.; and (iv) for general corporate purposes. The $288.2 million redemption of 2020 Notes was completed at a redemption price equal to par plus an applicable premium of $38.2 million plus $5.2 million of accrued and unpaid interest. On August 11, 2015, Summit Inc. raised $555.8 million, net of underwriting discounts, through the issuance of 22,425,000 shares of Class A common stock at a public offering price of $25.75 per share ("the August 2015 follow-on offering"). Summit Inc. used these proceeds to purchase 3,750,000 newly-issued LP Units from Summit Holdings and 18,675,000 LP Units from certain pre-IPO owners, at a purchase price per LP Unit equal to the public offering price per share of Class A common stock, less underwriting discounts and commissions. Summit Holdings used the proceeds from the 3,750,000 newly-issued LP Units to pay the deferred purchase price of $80.0 million related to the July 17, 2015 acquisition of a cement plant and quarry in Davenport, Iowa, and seven cement terminals along the Mississippi River (the “Davenport Assets”) and for general corporate purposes. Principles of Consolidation –The consolidated financial statements include the accounts of Summit LLC and its majority owned subsidiaries. All intercompany balances and transactions have been eliminated. The Company attributes consolidated member’s interest and net income separately to the controlling and noncontrolling interests. Noncontrolling interests in consolidated subsidiaries represent a 20% ownership in Ohio Valley Asphalt, LLC and, prior to the IPO and concurrent purchase of the noncontrolling interests of Continental Cement, a 30% redeemable ownership in Continental Cement. The Company accounts for investments in entities for which it has an ownership of 20% to 50% using the equity method of accounting. The Company’s fiscal year is based on a 52-53 week year with each quarter composed of 13 weeks ending on a Saturday. The 53-week year occurs approximately once every seven years and occurred in 2015. The additional week in the 53-week year was included in the fourth quarter of 2015. Use of Estimates — Preparation of these consolidated financial statements in conformity with U.S. generally accepted accounting principles (“U.S. GAAP”) requires management to make estimates and assumptions. These estimates and the underlying assumptions affect the amounts of assets and liabilities reported, disclosures about contingent assets and liabilities and reported amounts of revenue and expenses. Such estimates include the valuation of accounts receivable, inventories, valuation of deferred tax assets, goodwill, intangibles and other long-lived assets, pension and other postretirement obligations and asset retirement obligations. Estimates also include revenue earned on contracts and costs to complete contracts. Most of the Company’s paving and related services are performed under fixed unit-price contracts with state and local governmental entities. Management regularly evaluates its estimates and assumptions based on historical experience and other factors, including the current economic environment. As future events and their effects cannot be determined with precision, actual results can differ significantly from estimates made. Changes in estimates, including those resulting from continuing changes in the economic environment, are reflected in the Company’s consolidated financial statements when the change in estimate occurs. Business and Credit Concentrations— The Company’s operations are conducted primarily across 21 U.S. states and in British Columbia, Canada, with the most significant revenue generated in Texas, Kansas, Utah, and Missouri. The Company’s accounts receivable consist primarily of amounts due from customers within these areas. Therefore, collection of these accounts is dependent on the economic conditions in the aforementioned states, as well as specific situations affecting individual customers. Credit granted within the Company’s trade areas has been granted to many customers, and management does not believe that a significant concentration of credit exists with respect to any individual customer or group of customers. No single customer accounted for more than 10% of the Company’s total revenue in 2016, 2015 or 2014. Accounts Receivable —Accounts receivable are stated at the amount management expects to collect from outstanding balances. Management provides for probable uncollectible amounts through a charge to earnings and a credit to a valuation allowance based on its assessment of the collectability of individual accounts. In establishing the allowance, management considers historical losses adjusted to take into account current market conditions and its customers’ financial condition, the amount of receivables in dispute, the current receivables aging and current payment terms. Balances that remain outstanding after reasonable collection efforts are exercised are written off through a charge to the valuation allowance. The balances billed but not paid by customers, pursuant to retainage provisions included in contracts, are generally due upon completion of the contracts. Revenue and Cost Recognition —Revenue for product sales are recognized when evidence of an arrangement exists, the fee is fixed or determinable, title passes, which is generally when the product is shipped, and collection is reasonably assured. Product revenue includes sales of aggregates, cement and other materials to customers, net of discounts, allowances or taxes, as applicable. Revenue from construction contracts are included in service revenue and are recognized under the percentage-of-completion accounting method. The percent complete is measured by the cost incurred to date compared to the estimated total cost of each project. This method is used as management considers expended cost to be the best available measure of progress on these contracts, the majority of which are completed within one year, but may occasionally extend beyond one year. Inherent uncertainties in estimating costs make it at least reasonably possible that the estimates used will change within the near term and over the life of the contracts. Contract costs include all direct material and labor costs and those indirect costs related to contract performance and completion. Provisions for estimated losses on uncompleted contracts are made in the period in which such losses are estimable. General and administrative costs are charged to expense as incurred. Changes in job performance, job conditions and estimated profitability, including those arising from contract penalty provisions and final contract settlements, may result in revisions to costs and income. Such revisions are recognized in the period in which they are determined. An amount equal to contract costs incurred that are attributable to claims is included in revenue when realization is probable and the amount can be reliably estimated. Costs and estimated earnings in excess of billings are composed principally of revenue recognized on contracts (on the percentage-of-completion method) for which billings had not been presented to customers because the amount were not billable under the contract terms at the balance sheet date. In accordance with the contract terms, the unbilled receivables at December 31, 2016 will be billed in 2017. Billings in excess of costs and estimated earnings represent billings in excess of revenue recognized. Revenue from the receipt of waste fuels is classified as service revenue and is based on fees charged for the waste disposal, which are recognized when the waste is accepted. Inventories —Inventories consist of stone that has been removed from quarries and processed for future sale, cement, raw materials and finished concrete blocks. Inventories are valued at the lower of cost or market and are accounted for on a first-in first-out basis or an average cost basis. If items become obsolete or otherwise unusable or if quantities exceed what is projected to be sold within a reasonable period of time, they will be charged to costs of production in the period that the items are designated as obsolete or excess inventory. Stripping costs are costs of removing overburden and waste material to access aggregate materials and are recognized in cost of revenue in the same period as the revenue from the sale of the inventory. Property, Plant and Equipment, net —Property, plant and equipment are recorded at cost, less accumulated depreciation, depletion and amortization. Expenditures for additions and improvements that significantly add to the productive capacity or extend the useful life of an asset are capitalized. Repair and maintenance costs that do not substantially expand productive capacity or extend the life of property, plant and equipment are expensed as incurred. Landfill airspace is included in property, plant and equipment at cost and is amortized based on the portion of the airspace used during the period compared to the gross estimated value of available airspace, which is updated periodically as circumstances dictate. Management reassesses the landfill airspace capacity with any changes in value recorded in cost of revenue. Capitalized landfill costs include expenditures for the acquisition of land and related airspace, engineering and permitting costs, cell construction costs and direct site improvement costs. Upon disposal of an asset, the cost and related accumulated depreciation are removed from the Company’s accounts and any gain or loss is included in general and administrative expenses. Depreciation on property, plant and equipment, including assets subject to capital leases, is generally computed on a straight-line basis. Depletion of mineral reserves is computed based on the portion of the reserves used during the period compared to the gross estimated value of proven and probable reserves, which is updated periodically as circumstances dictate. Leasehold improvements are amortized on a straight-line basis over the lesser of the asset’s useful life or the remaining lease term. The estimated useful lives are generally as follows: Buildings and improvements 10 - 30 years Plant, machinery and equipment 15 - 20 years Office equipment 3 - 7 years Truck and auto fleet 5 - 8 years Mobile equipment and barges 6 - 8 years Landfill airspace and improvements 10 - 30 years Other 4 - 20 years The Company reviews the carrying value of property, plant and equipment for impairment whenever events or circumstances indicate that the carrying value of an asset may not be recoverable from the estimated future cash flows expected to result from its use and eventual disposition. Such indicators may include, among others, deterioration in general economic conditions, adverse changes in the markets in which an entity operates, increases in input costs that have a negative effect on earnings and cash flows or a trend of negative or declining cash flows over multiple periods. Property, plant and equipment is tested for impairment at the lowest level for which identifiable cash flows are largely independent of the cash flows of other assets. As a result, the property, plant and equipment impairment test is at a significantly lower level than the level at which goodwill is tested for impairment. In markets where the Company does not produce downstream products, such as ready-mix concrete, asphalt paving mix and paving and related services, the lowest level of largely independent identifiable cash flows is at the individual aggregates operation or a group of aggregates operations collectively serving a local market or the cement operations. Conversely, in vertically-integrated markets, the cash flows of the downstream and upstream businesses are not largely independently identifiable and the vertically-integrated operations are considered the lowest level of largely independent identifiable cash flows. Assets are assessed for impairment charges when identified for disposition. Projected losses from disposition are recognized in the period in which they become estimable, which may be in advance of the actual disposition. The net gain (loss) from asset dispositions recognized in general and administrative expenses in fiscal years 2016, 2015 and 2014 was $6.8 million, $23.5 million and ($2.6 million), respectively. No material impairment charges have been recognized on assets held for use in 2016, 2015 or 2014. The losses are commonly a result of the cash flows expected from selling the asset being less than the expected cash flows that could be generated from holding the asset for use. Accrued Mining and Landfill Reclamation —The mining reclamation reserve and financial commitments for landfill closure and post-closure activities are based on management’s estimate of future cost requirements to reclaim property at both currently operating and closed sites. Estimates of these obligations have been developed based on management’s interpretation of current requirements and proposed regulatory changes and are intended to approximate fair value. Costs are estimated in current dollars, inflated until the expected time of payment, using an inflation rate of 2.5%, and then discounted back to present value using a credit-adjusted, risk-free rate on obligations of similar maturity, adjusted to reflect the Company’s credit rating. Changes in the credit-adjusted, risk-free rate do not change recorded liabilities. However, subsequent increases in the recognized obligations are measured using a current credit-adjusted, risk-free rate. Decreases in the recognized obligations are measured at the initial credit-adjusted, risk-free rate. Significant changes in inflation rates or the amount or timing of future cost estimates typically result in both (1) a current adjustment to the recorded liability (and corresponding adjustment to the asset) and (2) a change in accretion of the liability and depreciation of the asset to be recorded prospectively over the remaining capacity of the unmined quarry or landfill. Intangible Assets —The Company’s intangible assets are primarily composed of lease agreements and reserve rights. The assets related to lease agreements reflect the submarket royalty rates paid under agreements, primarily, for extracting aggregates. The values were determined as of the respective acquisition dates by a comparison of market-royalty rates to contract-royalty rates. The reserve rights relate to aggregate reserves to which the Company has the rights of ownership, but do not own the reserves. The intangible assets are amortized on a straight-line basis over the lives of the leases. The following table shows intangible assets by type and in total: December 31, 2016 January 2, 2016 Gross Net Gross Net Carrying Accumulated Carrying Carrying Accumulated Carrying Amount Amortization Amount Amount Amortization Amount Leases $ $ $ $ $ $ Reserve rights Trade names Other Total intangible assets $ $ $ $ $ $ Amortization expense in 2016, 2015 and 2014 was $2.6 million, $2.2 million and $0.9 million, respectively. The estimated amortization expense for intangible assets for each of the next five years and thereafter is as follows: 2017 $ 2018 2019 2020 2021 Thereafter Total $ Goodwill —Goodwill represents the purchase price paid in excess of the fair value of net tangible and intangible assets acquired. Goodwill recorded in connection with the Company’s acquisitions is primarily attributable to the expected profitability, assembled workforces of the acquired businesses and the synergies expected to arise after the Company’s acquisition of those businesses. Goodwill is not amortized, but is tested annually for impairment as of the first day of the fourth quarter and at any time that events or circumstances indicate that goodwill may be impaired. A qualitative approach may first be applied to determine whether it is more likely than not that the estimated fair value of a reporting unit is less than its carrying amount. If, as a result of the qualitative assessment, it is determined that an impairment is more likely than not, the two-step quantitative impairment test is then performed, otherwise further analysis is not required. The two-step impairment test first identifies potential goodwill impairment for each reporting unit and then, if necessary, measures the amount of the impairment loss. Income Taxes —As a limited liability company, the Company’s federal and state income tax attributes are generally passed to its member. However, certain subsidiaries, or subsidiary groups, of the Company are taxable entities subject to income taxes in the United States and Canada, the provisions for which are included in the consolidated financial statements. Significant judgments and estimates are required in the determination of the consolidated income tax expense. For the Company’s taxable entities, deferred income tax assets and liabilities are computed for differences between the tax basis and financial statement amounts that will result in taxable or deductible amounts in the future based on enacted tax laws and rates applicable to the jurisdictions in which they arise and periods in which the differences are expected to affect taxable income. A valuation allowance is recognized for deferred tax assets if it is more likely than not that some portion or all of the net deferred tax assets will not be realized. In making such a determination, all available positive and negative evidence is considered, including future reversals of existing taxable temporary differences, projected future taxable income, tax-planning strategies, and results of recent operations. If the Company determines it would be able to realize its deferred tax assets for which a valuation allowance had been recorded then an adjustment would be made to the deferred tax asset valuation allowance, which would reduce the provision for income taxes. The Company evaluates the tax positions taken on income tax returns that remain open to examination by the respective tax authorities from prior years and positions expected to be taken on the current year tax returns to identify uncertain tax positions. Unrecognized tax benefits on uncertain tax positions are recorded on the basis of a two-step process in which (1) the Company determines whether it is more likely than not that the tax positions will be sustained on the basis of the technical merits of the position and (2) for those tax positions that meet the more-likely-than-not recognition threshold, the largest amount of tax benefit that is more than 50 percent likely to be realized upon ultimate settlement with the related tax authority is recognized. Interest and penalties related to unrecognized tax benefits are recorded as income tax expense. Fair Value Measurements— Certain acquisitions made by the Company require the payment of contingent amounts of purchase consideration. These payments are contingent on specified operating results being achieved in periods subsequent to the acquisition and will only be made if earn-out thresholds are achieved. Contingent consideration obligations are measured at fair value each reporting period. Any adjustments to fair value are recognized in earnings in the period identified. The Company has entered into interest rate derivatives on $200.0 million of its term loan borrowings to add stability to interest expense and to manage its exposure to interest rate movements. The effective portion of changes in the fair value of derivatives designated and that qualify as cash flow hedges is recorded in accumulated other comprehensive income and will be subsequently reclassified into earnings in the period that the hedged forecasted transaction affects earnings. The fair value of contingent consideration and derivatives as of December 31, 2016 and January 2, 2016 was: 2016 2015 Current portion of acquisition-related liabilities and Accrued expenses: Contingent consideration $ $ Cash flow hedges Acquisition-related liabilities and Other noncurrent liabilities Contingent consideration $ $ Cash flow hedges The fair value accounting guidance establishes the following fair value hierarchy that prioritizes the inputs used to measure fair value: Level 1 — Unadjusted quoted prices for identical assets or liabilities in active markets. Level 2 — Inputs other than Level 1 that are based on observable market data, either directly or indirectly. These include quoted prices for similar assets or liabilities in active markets, quoted prices for identical assets or liabilities in inactive markets, inputs that are observable that are not prices and inputs that are derived from or corroborated by observable markets. Level 3 — Valuations developed from unobservable data, reflecting the Company’s own assumptions, which market participants would use in pricing the asset or liability. The fair value of contingent consideration was based on unobservable, or Level 3, inputs, including projected probability-weighted cash payments and an 11.0% discount rate, which reflects a market discount rate. Changes in fair value may occur as a result of a change in actual or projected cash payments, the probability weightings applied by the Company to projected payments or a change in the discount rate. Significant increases or decreases in any of these inputs in isolation could result in a lower, or higher, fair value measurement. The fair value of the cash flow hedges are based on observable, or Level 2, inputs such as interest rates, bond yields and prices in inactive markets. There were no material adjustments to the fair value of contingent consideration in 2015 or to cash flow hedges in 2016 or 2015. In 2016, a $6.1 million increase in the fair value of contingent consideration was recognized as a result of a change in projected cash payments. Financial Instruments —The Company’s financial instruments include debt and certain acquisition-related liabilities (deferred consideration and noncompete obligations). The carrying value and fair value of these financial instruments as of December 31, 2016 and January 2, 2016 were: December 31, 2016 January 2, 2016 Fair Value Carrying Value Fair Value Carrying Value Level 2 Long-term debt (1) $ $ $ $ Level 3 Current portion of deferred consideration and noncompete obligations (2) Long term portion of deferred consideration and noncompete obligations (3) (1) (2) (3) The fair value of debt was determined based on observable, or Level 2 inputs, such as interest rates, bond yields and quoted prices in inactive markets. The fair values of the deferred consideration and noncompete obligations were determined based on unobservable, or Level 3, inputs, including the cash payment terms in the purchase agreements and a discount rate reflecting the Company’s credit risk. The discount rate used is generally consistent with that used when the obligations were initially recorded. Securities with a maturity of three months or less are considered cash equivalents and the fair value of these assets approximates their carrying value. New Accounting Standards — In January 2017, the Financial Accounting Standards Board (“FASB”) issued a new Accounting Standards Update (“ASU”) 2017-04 Intangibles - Goodwill and Other (Topic 350) , which simplifies the test for goodwill impairment. The ASU eliminates the two step goodwill impairment test and replaces it with a single step test. The single step test compares the carrying amount of a reporting unit to its fair value; if the carrying amount is greater than the fair value the difference is the amount of the goodwill impairment. Step zero is left unchanged. Therefore, entities that wish do a qualitative assessment are still permitted to do so. The ASU is effective for SEC filers for fiscal years beginning after December 15, 2020. However, the Company will early adopt this ASU as of the beginning of fiscal year 2017. In March 2016, the FASB issued a new accounting standard with targeted amendments to the accounting for employee share-based payments. ASU 2016-09, Improvements to Employee Share-Based Payment Accounting , requires that the income tax effect of share-based awards be recognized in the income statement and allows entities to elect an accounting method to recognize forfeitures as they occur or to estimate forfeitures, as is currently required. The ASU is effective for public entities for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2016. However, the Company early adopted this ASU as of the beginning of fiscal year 2016 and made an election to recognize forfeitures as they occur. The ASU adoption was applied using a modified retrospective method by means of a $1.7 million cumulative-effect adjustment to accumulated earnings as of the beginning of the fiscal year. In February 2016, the FASB issued a new accounting standard related to lease accounting, ASU No. 2016-02, Leases , which will result in lessees recognizing most leases on the balance sheet. Lessees are required to disclose more quantitative and qualitative information about their leases than current U.S. GAAP requires. The ASU is effective for public entities for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2018. As of December 31, 2016 and January 2, 2016, the Company’s undiscounted minimum contractual commitments under long-term operating leases, which were not recorded on the balance sheet, were $31.3 million and $21.9 million, respectively, which is an estimate of the effect to lease obligations and property, plant and equipment that the new accounting standard would have as of the dates noted, prior to the effect of discounting. In May 2014, the FASB issued a new accounting standard to improve and converge the financial reporting requirements for revenue from contracts with customers. ASU No. 2014-09, Revenue from Contracts with Customers , prescribes a five-step model for revenue recognition that will replace most existing revenue recognition guidance in U.S. GAAP. The ASU will supersede nearly all existing revenue recognition guidance under U.S. GAAP and provides that an entity recognize revenue when it transfers promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. This update also requires additional disclosure about the nature, amount, timing and uncertainty of revenue and cash flows arising from customer contracts, including significant judgments and changes in judgments, and assets recognized from costs incurred to obtain or fulfill a contract. ASU No. 2014-09 allows for either full retrospective or modified retrospective adoption. In July 2015, the FASB postponed the effective date of the new revenue standard by one year to the first quarter of 2018. Early adoption is permitted, but no earlier than 2017. In 2016, the Company established an implementation team (“team”) and engaged external advisers to develop a multi-phase plan to assess the Company’s business and contracts, as well as any changes to processes or systems to adopt the requirements of the new standard. The team has updated the assessment for new ASU updates and for newly acquired businesses. The team is in the process of developing its conclusions on several aspects of the standard including variable consideration, identification of performance obligations and the determination of when control of goods and services transfers to the Company’s customers. Reclassifications —Certain amounts in the prior year have been reclassified to conform to the presentation in the current period.

Acquisitions

Acquisitions	12 Months Ended
	Dec. 31, 2016
Acquisitions	(2) Acquisitions The Company has completed numerous acquisitions since its formation in 2009, which have been financed through a combination of debt and equity funding. The operations of each acquisition have been included in the Company’s consolidated results of operations since the respective closing dates of the acquisitions. The Company measures all assets acquired and liabilities assumed at their acquisition-date fair value. West segment · On October 3, 2016, the Company acquired Midland Concrete Ltd. (“Midland Concrete”), a ready-mix company with one plant servicing the Midland, Texas market. The acquisition was funded with cash on hand. · On August 19, 2016, the Company acquired H.C. Rustin Corporation (“Rustin”), a ready-mix company with 12 ready-mix plants servicing the Southern Oklahoma market. The acquisition was funded with cash on hand. · On April 29, 2016, the Company acquired Sierra Ready Mix, LLC (“Sierra Ready Mix”), a vertically integrated aggregates and ready-mix concrete business with one sand and gravel pit and two ready-mix concrete plants located in Las Vegas, Nevada. The acquisition was funded with cash on hand and $11.1 million of contingent consideration, $10.0 million of which related to the execution of a lease and the remaining to the achievement of certain earnings targets. The lease contingency criteria was met in 2016 and the $10.0 million of consideration was paid in the year ended December 31, 2016. · On December 11, 2015, the Company acquired all of the assets of Pelican Asphalt Company, LLC, an asphalt terminal business in Houston, Texas. The acquisition was funded with cash on hand. · On August 21, 2015, the Company acquired all of the stock of LeGrand Johnson Construction Co., a vertically integrated company based in Utah with five sand and gravel pits, four ready-mix concrete plants and three asphalt plants and servicing the northern and central Utah, western Wyoming and southern Idaho markets. The acquisition was funded with borrowings under the Company’s revolving credit facility. · On June 1, 2015, the Company acquired all of the stock of Lewis & Lewis, Inc., a vertically integrated business in Wyoming. The acquisition was funded with borrowings under the Company’s revolving credit facility. East segment · On August 26, 2016, the Company acquired R.D. Johnson Excavating Company, LLC and Asphalt Sales of Lawrence, LLC (“RD Johnson”), an asphalt producer and construction services company based in Lawrence, Kansas. The acquisition was funded with both cash on hand and borrowings under the Company’s revolving credit facility. · On August 8, 2016, the Company acquired the assets of Weldon Real Estate, LLC (“Weldon”) and the membership interests of Honey Creek Disposal Service, LLC. (‘‘Honey Creek’’). Honey Creek is a trash collection business, which was sold immediately after acquisition. The Company retained the building assets of Weldon, where its recycling business in Kansas is operated. The acquisition was funded with borrowings under the Company’s revolving credit facility. · On May 20, 2016, the Company acquired seven aggregates quarries in central and northwest Missouri from APAC-Kansas, Inc. and APAC-Missouri, Inc., subsidiaries of Oldcastle Materials, Inc. (“Oldcastle Assets”). The acquisition was funded with cash on hand. · On March 18, 2016, the Company acquired Boxley Materials Company (“Boxley Materials”), a vertically integrated company based in Roanoke, Virginia with six quarries, four ready-mix concrete plants and four asphalt plants. The acquisition was funded with a portion of the proceeds from $250.0 million of 8.500% senior notes issued on March 8, 2016 and due April 15, 2022 (see note 8). · On February 5, 2016, the Company acquired American Materials Company (“AMC”), an aggregates company with five sand and gravel pits servicing coastal North and South Carolina. The acquisition was funded with cash on hand. Cement segment · On August 30, 2016, the Company acquired two river-supplied cement and fly-ash distribution terminals in Southern Louisiana (“Angelle Assets”). The acquisition was funded with borrowings under the Company’s revolving credit facility. · On July 17, 2015, the Company completed the acquisition of the Davenport Assets, a cement plant and a quarry in Davenport, Iowa, and seven cement terminals along the Mississippi River for $450.0 million in cash and a cement distribution terminal in Bettendorf, Iowa, for which a $16.6 million gain on disposition was recognized in general and administrative expenses. The cash purchase price was funded through a combination of debt (see Note 8) and $80.0 million with proceeds from the August 2015 follow-on offering. Combined with the Company’s cement plant in Hannibal, Missouri, the Company has over two million short tons of cement capacity and eight cement distribution terminals along the Mississippi River from Minneapolis, Minnesota to New Orleans, Louisiana. The $170.1 million of goodwill that was acquired with the Davenport Assets reflects the value from estimated synergies and cost savings, primarily from the expanded geographic area, overhead cost reductions and best practice sharing of operating efficiencies between the acquired assets and the Company’s existing cement plant in Hannibal, Missouri. The Davenport Assets were immediately integrated into the Company’s existing cement operations such that it is not practicable to report revenue and net income separately for the Davenport Assets. The purchase price allocation for the 2016 acquisitions, excluding AMC, has not yet been finalized due to the recent timing of the acquisitions and status of the valuation of property, plant and equipment. The table below summarizes aggregated information regarding the fair values of the assets acquired and liabilities assumed as of the respective acquisition dates. Information related to the 2016 acquisitions is shown on an aggregated basis as the acquisitions were not material individually, or collectively. Year ended Davenport Year Ended December 31, July 17, January 2, 2016 2016 2015 (excluding Davenport) Financial assets $ $ — $ Inventories Property, plant and equipment Intangible assets — — Other assets Financial liabilities Other long-term liabilities Net assets acquired Goodwill Purchase price Acquisition related liabilities — Bettendorf assets — Other — — Net cash paid for acquisitions $ $ $
Summit Materials, LLC
Acquisitions	(2) Acquisitions The Company has completed numerous acquisitions since its formation in 2009, which have been financed through a combination of debt and equity funding. The operations of each acquisition have been included in the Company’s consolidated results of operations since the respective closing dates of the acquisitions. The Company measures all assets acquired and liabilities assumed at their acquisition-date fair value. West segment · On October 3, 2016, the Company acquired Midland Concrete Ltd. (“Midland Concrete”), a ready-mix company with one plant servicing the Midland, Texas market. The acquisition was funded with cash on hand. · On August 19, 2016, the Company acquired H.C. Rustin Corporation (“Rustin”), a ready-mix company with 12 ready-mix plants servicing the Southern Oklahoma market. The acquisition was funded with cash on hand. · On April 29, 2016, the Company acquired Sierra Ready Mix, LLC (“Sierra Ready Mix”), a vertically integrated aggregates and ready-mix concrete business with one sand and gravel pit and two ready-mix concrete plants located in Las Vegas, Nevada. The acquisition was funded with cash on hand and $11.1 million of contingent consideration, $10.0 million of which related to the execution of a lease and the remaining to the achievement of certain earnings targets. The lease contingency criteria was met in 2016 and the $10.0 million of consideration was paid in the year ended December 31, 2016 . · On December 11, 2015, the Company acquired all of the assets of Pelican Asphalt Company, LLC, an asphalt terminal business in Houston, Texas. The acquisition was funded with cash on hand. · On August 21, 2015, the Company acquired all of the stock of LeGrand Johnson Construction Co., a vertically integrated company based in Utah with five sand and gravel pits, four ready-mix concrete plants and three asphalt plants and servicing the northern and central Utah, western Wyoming and southern Idaho markets. The acquisition was funded with borrowings under the Company’s revolving credit facility. · On June 1, 2015, the Company acquired all of the stock of Lewis & Lewis, Inc., a vertically integrated business in Wyoming. The acquisition was funded with borrowings under the Company’s revolving credit facility. East segment · On August 26, 2016, the Company acquired R.D. Johnson Excavating Company, LLC and Asphalt Sales of Lawrence, LLC (“RD Johnson”), an asphalt producer and construction services company based in Lawrence, Kansas. The acquisition was funded with both cash on hand and borrowings under the Company’s revolving credit facility. · On August 8, 2016, the Company acquired the assets of Weldon Real Estate, LLC (“Weldon”) and the membership interests of Honey Creek Disposal Service, LLC. (‘‘Honey Creek’’). Honey Creek is a trash collection business, which was sold immediately after acquisition. The Company retained the building assets of Weldon, where its recycling business in Kansas is operated. The acquisition was funded with borrowings under the Company’s revolving credit facility. · On May 20, 2016, the Company acquired seven aggregates quarries in central and northwest Missouri from APAC-Kansas, Inc. and APAC-Missouri, Inc., subsidiaries of Oldcastle Materials, Inc. (“Oldcastle Assets”). The acquisition was funded with cash on hand. · On March 18, 2016, the Company acquired Boxley Materials Company (“Boxley Materials”), a vertically integrated company based in Roanoke, Virginia with six quarries, four ready-mix concrete plants and four asphalt plants. The acquisition was funded with a portion of the proceeds from $250.0 million of 8.500% senior notes issued on March 8, 2016 and due April 15, 2022 (see note 8). · On February 5, 2016, the Company acquired American Materials Company (“AMC”), an aggregates company with five sand and gravel pits servicing coastal North and South Carolina. The acquisition was funded with cash on hand. Cement segment · On August 30, 2016, the Company acquired two river-supplied cement and fly-ash distribution terminals in Southern Louisiana (“Angelle Assets”). The acquisition was funded with borrowings under the Company’s revolving credit facility. · On July 17, 2015, the Company completed the acquisition of the Davenport Assets, a cement plant and a quarry in Davenport, Iowa, and seven cement terminals along the Mississippi River for $450.0 million in cash and a cement distribution terminal in Bettendorf, Iowa, for which a $16.6 million gain on disposition was recognized in general and administrative expenses. The cash purchase price was funded through a combination of debt (see Note 8) and $80.0 million with proceeds from the August 2015 follow-on offering. Combined with the Company’s cement plant in Hannibal, Missouri, the Company has over two million short tons of cement capacity and eight cement distribution terminals along the Mississippi River from Minneapolis, Minnesota to New Orleans, Louisiana. The $170.1 million of goodwill that was acquired with the Davenport Assets reflects the value from estimated synergies and cost savings, primarily from the expanded geographic area, overhead cost reductions and best practice sharing of operating efficiencies between the acquired assets and the Company’s existing cement plant in Hannibal, Missouri. The Davenport Assets were immediately integrated into the Company’s existing cement operations such that it is not practicable to report revenue and net income separately for the Davenport Assets. The purchase price allocation for the 2016 acquisitions, excluding AMC, has not yet been finalized due to the recent timing of the acquisitions and status of the valuation of property, plant and equipment. The table below summarizes aggregated information regarding the fair values of the assets acquired and liabilities assumed as of the respective acquisition dates. Information related to the 2016 acquisitions is shown on an aggregated basis as the acquisitions were not material individually, or collectively. Year ended Davenport Year Ended December 31, July 17, January 2, 2016 2016 2015 (excluding Davenport) Financial assets $ $ — $ Inventories Property, plant and equipment Intangible assets — — Other assets Financial liabilities Other long-term liabilities Net assets acquired Goodwill Purchase price Acquisition related liabilities — Bettendorf assets — Other — — Net cash paid for acquisitions $ $ $

Goodwill

Goodwill	12 Months Ended
	Dec. 31, 2016
Goodwill	(3) Goodwill As of December 31, 2016, the Company had 12 reporting units with goodwill for which the annual goodwill impairment test was completed. To perform the annual impairment test on the first day of the fourth quarter of 2016, seven of our reporting units were assessed under a qualitative assessment. As a result of this analysis, it was determined that it is more likely than not that the fair value of the seven reporting units were greater than its carrying value. Accordingly, for those reporting units, the two-step quantitative impairment test was not performed. For the remaining reporting units, Step 1 of the impairment test was performed. The Company estimated the fair value of the reporting units using an income approach (i.e., a discounted cash flow technique) and a market approach. These valuation methods used Level 2 and Level 3 assumptions, including, but not limited to, sales prices of similar assets, assumptions related to future profitability, cash flows, and discount rates. These estimates are based upon historical trends, management’s knowledge and experience and overall economic factors, including projections of future earnings potential. Developing discounted future cash flow estimates in applying the income approach required management to evaluate its intermediate to longer-term strategies, including, but not limited to, estimates about revenue growth, operating margins, capital requirements, inflation and working capital management. The development of appropriate rates to discount the estimated future cash flows required the selection of risk premiums, which can materially affect the present value of estimated future cash flows. Based on this analysis, it was determined that the reporting units’ fair values were greater than their carrying values and no impairment charges were recognized in 2016. The accumulated impairment charges recognized in prior periods totaled $68.2 million. The following table presents goodwill by reportable segments and in total: West East Cement Total Balance, December 27, 2014 $ $ $ $ Acquisitions Foreign currency translation adjustments — — Balance, January 2, 2016 $ $ $ $ Acquisitions(1) Foreign currency translation adjustments — — Balance, December 31, 2016 $ $ $ $ Accumulated impairment losses as of December 31, 2016 and January 2, 2016 $ $ $ — $ (1) Reflects goodwill from 2016 acquisitions and working capital adjustments from prior year acquisitions in the West and Cement segments, including $5.4 million related to below-market contracts assumed with the Davenport Assets acquisition.
Summit Materials, LLC
Goodwill	(3) Goodwill As of December 31, 2016, the Company had 12 reporting units with goodwill for which the annual goodwill impairment test was completed. To perform the annual impairment test on the first day of the fourth quarter of 2016, seven of our reporting units were assessed under a qualitative assessment. As a result of this analysis, it was determined that it is more likely than not that the fair value of the seven reporting units were greater than its carrying value. Accordingly, for those reporting units, the two-step quantitative impairment test was not performed. For the remaining reporting units, Step 1 of the impairment test was performed. The Company estimated the fair value of the reporting units using an income approach (i.e., a discounted cash flow technique) and a market approach. These valuation methods used Level 2 and Level 3 assumptions, including, but not limited to, sales prices of similar assets, assumptions related to future profitability, cash flows, and discount rates. These estimates are based upon historical trends, management’s knowledge and experience and overall economic factors, including projections of future earnings potential. Developing discounted future cash flow estimates in applying the income approach required management to evaluate its intermediate to longer-term strategies, including, but not limited to, estimates about revenue growth, operating margins, capital requirements, inflation and working capital management. The development of appropriate rates to discount the estimated future cash flows required the selection of risk premiums, which can materially affect the present value of estimated future cash flows. Based on this analysis, it was determined that the reporting units’ fair values were greater than their carrying values and no impairment charges were recognized in 2016. The accumulated impairment charges recognized in prior periods totaled $68.2 million. The following table presents goodwill by reportable segments and in total: West East Cement Total Balance, December 27, 2014 $ $ $ $ Acquisitions Foreign currency translation adjustments — — Balance, January 2, 2016 $ $ $ $ Acquisitions(1) Foreign currency translation adjustments — — Balance, December 31, 2016 $ $ $ $ Accumulated impairment losses as of December 31, 2016 and January 2, 2016 $ $ $ — $ (1) Reflects goodwill from 2016 acquisitions and working capital adjustments from prior year acquisitions in the West and Cement segments, including $5.4 million related to below-market contracts assumed with the Davenport Assets acquisition.

Accounts Receivable, Net

Accounts Receivable, Net	12 Months Ended
	Dec. 31, 2016
Accounts Receivable, Net	(4) Accounts Receivable, Net Accounts receivable, net consisted of the following as of December 31, 2016 and January 2, 2016: 2016 2015 Trade accounts receivable $ $ Retention receivables Receivables from related parties Accounts receivable Less: Allowance for doubtful accounts Accounts receivable, net $ $ Retention receivables are amounts earned by the Company but held by customers until paving and related service contracts and projects are near completion or fully completed. Amounts are generally billed and collected within one year.
Summit Materials, LLC
Accounts Receivable, Net	(4) Accounts Receivable, Net Accounts receivable, net consisted of the following as of December 31, 2016 and January 2, 2016: 2016 2015 Trade accounts receivable $ $ Retention receivables Receivables from related parties Accounts receivable Less: Allowance for doubtful accounts Accounts receivable, net $ $ Retention receivables are amounts earned by the Company but held by customers until paving and related service contracts and projects are near completion or fully completed. Amounts are generally billed and collected within one year.

Inventories

Inventories	12 Months Ended
	Dec. 31, 2016
Inventories	(5) Inventories Inventories consisted of the following as of December 31, 2016 and January 2, 2016: 2016 2015 Aggregate stockpiles $ $ Finished goods Work in process Raw materials Total $ $
Summit Materials, LLC
Inventories	(5) Inventories Inventories consisted of the following as of December 31, 2016 and January 2, 2016: 2016 2015 Aggregate stockpiles $ $ Finished goods Work in process Raw materials Total $ $

Property, Plant and Equipment,

Property, Plant and Equipment, net	12 Months Ended
	Dec. 31, 2016
Property, Plant and Equipment, net	(6) Property, Plant and Equipment, net Property, plant and equipment, net consisted of the following as of December 31, 2016 and January 2, 2016: 2016 2015 Land (mineral bearing) and asset retirement costs $ $ Land (non-mineral bearing) Buildings and improvements Plants, machinery and equipment Mobile equipment and barges Truck and auto fleet Landfill airspace and improvements Office equipment Construction in progress Property, plant and equipment Less accumulated depreciation, depletion and amortization Property, plant and equipment, net $ $ Depreciation, depletion and amortization expense of property, plant and equipment was $144.2 million, $111.6 million and $85.8 million in the years ended December 31, 2016, January 2, 2016 and December 27, 2014, respectively. Property, plant and equipment at December 31, 2016 and January 2, 2016 included $49.8 million and $47.0 million, respectively, of capital leases for certain equipment and a building with accumulated amortization of $10.6 million and $7.0 million, respectively. The equipment leases generally have terms of less than five years and the building lease had an original term of 30 years. Approximately $11.8 million and $15.3 million of the future obligations associated with the capital leases are included in accrued expenses as of December 31, 2016 and January 2, 2016, respectively, and the present value of the remaining capital lease payments, $27.5 million and $29.5 million, respectively, is included in other noncurrent liabilities on the consolidated balance sheets. Future minimum rental commitments under long-term capital leases are $13.6 million, $17.6 million, $5.7 million, $2.6 million, and $0.7 million for the years ended 2017, 2018, 2019, 2020 and 2021, respectively.
Summit Materials, LLC
Property, Plant and Equipment, net	(6) Property, Plant and Equipment, net Property, plant and equipment, net consisted of the following as of December 31, 2016 and January 2, 2016: 2016 2015 Land (mineral bearing) and asset retirement costs $ $ Land (non-mineral bearing) Buildings and improvements Plants, machinery and equipment Mobile equipment and barges Truck and auto fleet Landfill airspace and improvements Office equipment Construction in progress Property, plant and equipment Less accumulated depreciation, depletion and amortization Property, plant and equipment, net $ $ Depreciation, depletion and amortization expense of property, plant and equipment was $144.2 million, $111.6 million and $85.8 million in the years ended December 31, 2016, January 2, 2016 and December 27, 2014, respectively. Property, plant and equipment at December 31, 2016 and January 2, 2016 included $49.8 million and $47.0 million, respectively, of capital leases for certain equipment and a building with accumulated amortization of $10.6 million and $7.0 million, respectively. The equipment leases generally have terms of less than five years and the building lease had an original term of 30 years. Approximately $11.8 million and $15.3 million of the future obligations associated with the capital leases are included in accrued expenses as of December 31, 2016 and January 2, 2016, respectively, and the present value of the remaining capital lease payments, $27.5 million and $29.5 million, respectively, is included in other noncurrent liabilities on the consolidated balance sheets. Future minimum rental commitments under long-term capital leases are $13.6 million, $17.6 million, $5.7 million, $2.6 million, and $0.7 million for the years ended 2017, 2018, 2019, 2020 and 2021, respectively.

Accrued Expenses

Accrued Expenses	12 Months Ended
	Dec. 31, 2016
Accrued Expenses	(7) Accrued Expenses Accrued expenses consisted of the following as of December 31, 2016 and January 2, 2016: 2016 2015 Interest $ $ Payroll and benefits Capital lease obligations Insurance Non-income taxes Professional fees Other(1) Total $ $ (1) Consists primarily of subcontractor and working capital settlement accruals and deferred revenue.
Summit Materials, LLC
Accrued Expenses	(7) Accrued Expenses Accrued expenses consisted of the following as of December 31, 2016 and January 2, 2016: 2016 2015 Interest $ $ Payroll and benefits Capital lease obligations Insurance Non-income taxes Professional fees Other(1) Total $ $ (1) Consists primarily of subcontractor and working capital settlement accruals and deferred revenue.

Debt

Debt	12 Months Ended
	Dec. 31, 2016
Debt	(8) Debt Debt consisted of the following as of December 31, 2016 and January 2, 2016: 2016 2015 Term Loan, due 2022: $640.3 million and $646.8 million, net of $2.6 million and $3.1 million discount at December 31, 2016 and January 2, 2016, respectively $ $ 8 1 ⁄ 2 % Senior Notes, due 2022 — 6 1 ⁄ 8 % Senior Notes, due 2023: $650 million, net of $1.6 million and $1.8 million discount at December 31, 2016 and January 2, 2016, respectively Total Current portion of long-term debt Long-term debt $ $ The contractual payments of long-term debt, including current maturities, for the five years subsequent to December 31, 2016, are as follows: 2017 $ 2018 2019 2020 2021 Thereafter Total Less: Original issue net discount Less: Capitalized loan costs Total debt $ Senior Notes — On March 8, 2016, Summit LLC and Summit Materials Finance Corp., an indirect wholly-owned subsidiary of Summit LLC ("Finance Corp." and with Summit LLC, the “Issuers”) issued $250.0 million of 8.500% senior notes due April 15, 2022 (the “2022 Notes”). The 2022 Notes were issued at 100.0% of their par value with proceeds of $246.3 million, net of related fees and expenses. The proceeds from the sale of the 2022 Notes were used to fund the acquisition of Boxley Materials, replenish cash used for the acquisition of AMC and pay expenses incurred in connection with these acquisitions. The 2022 Notes were issued under an indenture dated March 8, 2016 (as amended and supplemented, the “2016 Indenture”). The 2016 Indenture contains covenants limiting, among other things, Summit LLC and its restricted subsidiaries’ ability to incur additional indebtedness or issue certain preferred shares, pay dividends, redeem stock or make other distributions, make certain investments, sell or transfer certain assets, create liens, consolidate, merge, sell or otherwise dispose of all or substantially all of its assets, enter into certain transactions with affiliates, and designate subsidiaries as unrestricted subsidiaries. The 2016 Indenture also contains customary events of default. Interest on the 2022 Notes is payable semi-annually in arrears on April 15 and October 15 of each year commencing on October 15, 2016. In 2015, the Issuers issued $650.0 million of 6.125% senior notes due July 2023 (the "2023 Notes” and collectively with the 2022 Notes, the “Senior Notes”). The net proceeds from the 2023 Notes, with proceeds from the refinancing of the term loan described below, were used to pay the $370.0 million initial purchase price for the Davenport Assets, to redeem $336.8 million in aggregate principal amount of the then outstanding 2020 Notes and pay related fees and expenses. Of the aggregate $650.0 million of 2023 Notes, $350.0 million were issued at par and $300.0 million were issued at 99.375% of par. The 2023 Notes were issued under an indenture dated July 8, 2015, the terms of which are generally consistent with the 2016 Indenture. Interest on the 2023 Notes is payable semi-annually in arrears on January 15 and July 15 of each year commencing on January 15, 2016. In April, August and November 2015, using proceeds from the IPO, the refinancing of the term loan described below and the proceeds from the 2023 Notes, $288.2 million, $183.0 million and $153.8 million, respectively, in aggregate principal amount of the then outstanding 2020 Notes were redeemed at a price equal to par plus an applicable premium and the indenture under which the 2020 Notes were issued was satisfied and discharged. As a result of the redemptions, net charges of $56.5 million were recognized for the year ended January 2, 2016. The fees included $66.6 million for the applicable prepayment premium and $11.9 million for the write-off of deferred financing fees, partially offset by $22.0 million of net benefit from the write-off of the original issuance net premium. Senior Secured Credit Facilities — Summit LLC has credit facilities that provide for term loans in an aggregate amount of $650.0 million and revolving credit commitments in an aggregate amount of $235.0 million (the “Senior Secured Credit Facilities”). Under the Senior Secured Credit Facilities, required principal repayments of 0.25% of term debt are due on the last business day of each March, June, September and December. The unpaid principal balance is due in full on the maturity date, which is July 17, 2022. On July 17, 2015, Summit LLC refinanced its term loan under the Senior Secured Credit Facilities (the “Refinancing”). The Refinancing, among other things: (i) reduced the applicable margins used to calculate interest rates for term loans under the Senior Secured Credit Facilities to 3.25% for LIBOR rate loans and 2.25% for base rate loans, subject to a LIBOR floor of 1.00% (and one 25 basis point step down upon Summit LLC achieving a certain first lien net leverage ratio); (ii) increased term loans borrowed under the term loan facility from $422.0 million to an aggregate $650.0 million; and (iii) created additional flexibility under the financial maintenance covenants, which are tested quarterly, by increasing the applicable maximum Consolidated First Lien Net Leverage Ratio (as defined in the credit agreement governing the Senior Secured Credit Facilities, the “Credit Agreement”). On March 11, 2015, Summit LLC entered into Amendment No. 3 to the Credit Agreement, which became effective on March 17, 2015 upon the consummation of the IPO. The amendment: (i) increased the size of the revolving credit facility from $150.0 million to $235.0 million; (ii) extended the maturity date of the revolving credit facility to March 11, 2020; (iii) amended certain covenants; and (iv) permits periodic tax distributions as contemplated in a tax receivable agreement, dated March 11, 2015. As a result of this amendment, $0.8 million of charges were recognized for the year ended January 2, 2016. The revolving credit facility bears interest per annum equal to, at Summit LLC’s option, either (i) a base rate determined by reference to the highest of (a) the federal funds rate plus 0.50%, (b) the prime rate of Bank of America, N.A. and (c) LIBOR plus 1.00%, plus an applicable margin of 2.25% for base rate loans or (ii) a LIBOR rate determined by reference to Reuters prior to the interest period relevant to such borrowing adjusted for certain additional costs plus an applicable margin of 3.25% for LIBOR rate loans. There were no outstanding borrowings under the revolving credit facility as of December 31, 2016 and January 2, 2016, leaving remaining borrowing capacity of $209.4 million, which is net of $25.6 million of outstanding letters of credit. The outstanding letters of credit are renewed annually and support required bonding on construction projects and the Company’s insurance liabilities. Summit LLC’s Consolidated First Lien Net Leverage Ratio, as such term is defined in the Credit Agreement, should be no greater than 4.75:1.0 as of each quarter-end. As of December 31, 2016 and January 2, 2016, Summit LLC was in compliance with all financial covenants. Summit LLC’s wholly-owned domestic subsidiary companies, subject to certain exclusions and exceptions, are named as subsidiary guarantors of the Senior Notes and the Senior Secured Credit Facilities. In addition, Summit LLC has pledged substantially all of its assets as collateral, subject to certain exclusions and exceptions, for the Senior Secured Credit Facilities. Interest expense related to debt totaled $83.8 million, $73.6 million and $78.6 million for the years ended December 31, 2016, January 2, 2016 and December 27, 2014, respectively. The following table presents the activity for the deferred financing fees for the years ended December 31, 2016 and January 2, 2016: Deferred financing fees Balance—December 27, 2014 $ Loan origination fees Amortization Write off of deferred financing fees Balance—January 2, 2016 $ Loan origination fees Amortization Balance—December 31, 2016 $ Other —On January 15, 2015, the Company’s wholly-owned subsidiary in British Columbia, Canada entered into an agreement with HSBC for a (i) $6.0 million Canadian dollar (“CAD”) revolving credit commitment to be used for operating activities that bears interest per annum equal to the bank’s prime rate plus 0.20%, (ii) $0.5 million CAD revolving credit commitment to be used for capital equipment that bears interest per annum at the bank’s prime rate plus 0.90% and (iii) $0.4 million CAD revolving credit commitment to provide guarantees on behalf of that subsidiary. There were no amounts outstanding under this agreement as of December 31, 2016 or January 2, 2016.
Summit Materials, LLC
Debt	(8) Debt Debt consisted of the following as of December 31, 2016 and January 2, 2016: 2016 2015 Term Loan, due 2022: $640.3 million and $646.8 million, net of $2.6 million and $3.1 million discount at December 31, 2016 and January 2, 2016, respectively $ $ 8 1 ⁄ 2 % Senior Notes, due 2022 — 6 1 ⁄ 8 % Senior Notes, due 2023: $650 million, net of $1.6 million and $1.8 million discount at December 31, 2016 and January 2, 2016, respectively Total Current portion of long-term debt Long-term debt $ $ The contractual payments of long-term debt, including current maturities, for the five years subsequent to December 31, 2016, are as follows: 2017 $ 2018 2019 2020 2021 Thereafter Total Less: Original issue net discount Less: Capitalized loan costs Total debt $ Senior Notes — On March 8, 2016, Summit LLC and Summit Materials Finance Corp., an indirect wholly-owned subsidiary of Summit LLC ("Finance Corp." and with Summit LLC, the “Issuers”) issued $250.0 million of 8.500% senior notes due April 15, 2022 (the “2022 Notes”). The 2022 Notes were issued at 100.0% of their par value with proceeds of $246.3 million, net of related fees and expenses. The proceeds from the sale of the 2022 Notes were used to fund the acquisition of Boxley Materials, replenish cash used for the acquisition of AMC and pay expenses incurred in connection with these acquisitions. The 2022 Notes were issued under an indenture dated March 8, 2016 (as amended and supplemented, the “2016 Indenture”). The 2016 Indenture contains covenants limiting, among other things, Summit LLC and its restricted subsidiaries’ ability to incur additional indebtedness or issue certain preferred shares, pay dividends, redeem stock or make other distributions, make certain investments, sell or transfer certain assets, create liens, consolidate, merge, sell or otherwise dispose of all or substantially all of its assets, enter into certain transactions with affiliates, and designate subsidiaries as unrestricted subsidiaries. The 2016 Indenture also contains customary events of default. Interest on the 2022 Notes is payable semi-annually in arrears on April 15 and October 15 of each year commencing on October 15, 2016. In 2015, the Issuers issued $650.0 million of 6.125% senior notes due July 2023 (the "2023 Notes” and collectively with the 2022 Notes, the “Senior Notes”). The net proceeds from the 2023 Notes, with proceeds from the refinancing of the term loan described below, were used to pay the $370.0 million initial purchase price for the Davenport Assets, to redeem $336.8 million in aggregate principal amount of the then outstanding 2020 Notes and pay related fees and expenses. Of the aggregate $650.0 million of 2023 Notes, $350.0 million were issued at par and $300.0 million were issued at 99.375% of par. The 2023 Notes were issued under an indenture dated July 8, 2015, the terms of which are generally consistent with the 2016 Indenture. Interest on the 2023 Notes is payable semi-annually in arrears on January 15 and July 15 of each year commencing on January 15, 2016. In April, August and November 2015, using proceeds from the IPO, the refinancing of the term loan described below and the proceeds from the 2023 Notes, $288.2 million, $183.0 million and $153.8 million, respectively, in aggregate principal amount of the then outstanding 2020 Notes were redeemed at a price equal to par plus an applicable premium and the indenture under which the 2020 Notes were issued was satisfied and discharged. As a result of the redemptions, net charges of $56.5 million were recognized for the year ended January 2, 2016. The fees included $66.6 million for the applicable prepayment premium and $11.9 million for the write-off of deferred financing fees, partially offset by $22.0 million of net benefit from the write-off of the original issuance net premium. Senior Secured Credit Facilities — Summit LLC has credit facilities that provide for term loans in an aggregate amount of $650.0 million and revolving credit commitments in an aggregate amount of $235.0 million (the “Senior Secured Credit Facilities”). Under the Senior Secured Credit Facilities, required principal repayments of 0.25% of term debt are due on the last business day of each March, June, September and December. The unpaid principal balance is due in full on the maturity date, which is July 17, 2022. On July 17, 2015, Summit LLC refinanced its term loan under the Senior Secured Credit Facilities (the “Refinancing”). The Refinancing, among other things: (i) reduced the applicable margins used to calculate interest rates for term loans under the Senior Secured Credit Facilities to 3.25% for LIBOR rate loans and 2.25% for base rate loans, subject to a LIBOR floor of 1.00% (and one 25 basis point step down upon Summit LLC achieving a certain first lien net leverage ratio); (ii) increased term loans borrowed under the term loan facility from $422.0 million to an aggregate $650.0 million; and (iii) created additional flexibility under the financial maintenance covenants, which are tested quarterly, by increasing the applicable maximum Consolidated First Lien Net Leverage Ratio (as defined in the credit agreement governing the Senior Secured Credit Facilities, the “Credit Agreement”). On March 11, 2015, Summit LLC entered into Amendment No. 3 to the Credit Agreement, which became effective on March 17, 2015 upon the consummation of the IPO. The amendment: (i) increased the size of the revolving credit facility from $150.0 million to $235.0 million; (ii) extended the maturity date of the revolving credit facility to March 11, 2020; (iii) amended certain covenants; and (iv) permits periodic tax distributions as contemplated in a tax receivable agreement, dated March 11, 2015. As a result of this amendment, $0.8 million of charges were recognized for the year ended January 2, 2016. The revolving credit facility bears interest per annum equal to, at Summit LLC’s option, either (i) a base rate determined by reference to the highest of (a) the federal funds rate plus 0.50%, (b) the prime rate of Bank of America, N.A. and (c) LIBOR plus 1.00%, plus an applicable margin of 2.25% for base rate loans or (ii) a LIBOR rate determined by reference to Reuters prior to the interest period relevant to such borrowing adjusted for certain additional costs plus an applicable margin of 3.25% for LIBOR rate loans. There were no outstanding borrowings under the revolving credit facility as of December 31, 2016 and January 2, 2016, leaving remaining borrowing capacity of $209.4 million, which is net of $25.6 million of outstanding letters of credit. The outstanding letters of credit are renewed annually and support required bonding on construction projects and the Company’s insurance liabilities. Summit LLC’s Consolidated First Lien Net Leverage Ratio, as such term is defined in the Credit Agreement, should be no greater than 4.75:1.0 as of each quarter-end. As of December 31, 2016 and January 2, 2016, Summit LLC was in compliance with all financial covenants. Summit LLC’s wholly-owned domestic subsidiary companies, subject to certain exclusions and exceptions, are named as subsidiary guarantors of the Senior Notes and the Senior Secured Credit Facilities. In addition, Summit LLC has pledged substantially all of its assets as collateral, subject to certain exclusions and exceptions, for the Senior Secured Credit Facilities. Interest expense related to debt totaled $83.8 million, $73.6 million and $78.6 million for the years ended December 31, 2016, January 2, 2016 and December 27, 2014, respectively. The following table presents the activity for the deferred financing fees for the years ended December 31, 2016 and January 2, 2016: Deferred financing fees Balance—December 27, 2014 $ Loan origination fees Amortization Write off of deferred financing fees Balance—January 2, 2016 $ Loan origination fees Amortization Balance—December 31, 2016 $ Other —On January 15, 2015, the Company’s wholly-owned subsidiary in British Columbia, Canada entered into an agreement with HSBC for a (i) $6.0 million Canadian dollar (“CAD”) revolving credit commitment to be used for operating activities that bears interest per annum equal to the bank’s prime rate plus 0.20%, (ii) $0.5 million CAD revolving credit commitment to be used for capital equipment that bears interest per annum at the bank’s prime rate plus 0.90% and (iii) $0.4 million CAD revolving credit commitment to provide guarantees on behalf of that subsidiary. There were no amounts outstanding under this agreement as of December 31, 2016 or January 2, 2016.

Accumulated Other Comprehensive

Accumulated Other Comprehensive Income (Loss)	12 Months Ended
	Dec. 31, 2016
Accumulated Other Comprehensive Income (Loss)	(9) Accumulated Other Comprehensive Income (Loss) The changes in each component of accumulated other comprehensive income (loss) consisted of the following: Accumulated Foreign currency other Change in translation Cash flow hedge comprehensive retirement plans adjustments adjustments loss (income) Balance — December 27, 2014 $ — $ — $ — $ — Postretirement liability adjustment — — Foreign currency translation adjustment — — Loss on cash flow hedges — — Balance — January 2, 2016 $ $ $ $ Postretirement liability adjustment — — Foreign currency translation adjustment — — Loss on cash flow hedges — — Balance — December 31, 2016 $ $ $ $
Summit Materials, LLC
Accumulated Other Comprehensive Income (Loss)	(9) Accumulated Other Comprehensive Loss The changes in each component of accumulated other comprehensive loss consisted of the following: Accumulated Foreign currency other Change in translation Cash flow hedge comprehensive retirement plans adjustments adjustments loss Balance — December 28, 2013 $ $ — $ — $ Postretirement curtailment adjustment — — Postretirement liability adjustment — — Foreign currency translation adjustment — — Balance — December 27, 2014 $ $ $ — $ Postretirement liability adjustment — — Foreign currency translation adjustment — — Loss on cash flow hedges — — Balance — January 2, 2016 $ $ $ $ Postretirement liability adjustment — — Foreign currency translation adjustment — — Loss on cash flow hedges — — Balance — December 31, 2016 $ $ $ $

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2016
Income Taxes	(10) Income Taxes Summit Inc.’s tax provision includes its proportional share of Summit Holdings’ tax attributes. Summit Holdings’ subsidiaries are primarily limited liability companies, but do include certain entities organized as C corporations and a Canadian subsidiary. The tax attributes related to the limited liability companies are passed on to Summit Holdings and then to its partners, including Summit Inc. The tax attributes associated with the C corporation and Canadian subsidiaries are fully reflected in the Company’s accounts. For the years ended December 31, 2016, January 2, 2016 and December 27, 2014, income taxes consisted of the following: 2016 2015 2014 Provision for income taxes: Current $ $ $ Deferred Income tax benefit $ $ $ The effective tax rate on pre-tax income differs from the U.S. statutory rate of 35% due to the following: 2016 2015 2014 Income tax expense (benefit) at federal statutory tax rate $ $ $ Less: Income tax benefit at federal statutory tax rate for LLC entities State and local income taxes Permanent differences Effective tax rate change Valuation allowance — Impact of LP Unit ownership change — — Other Income tax benefit $ $ $ The following table summarizes the components of the net deferred income tax asset (liability) as December 31, 2016 and January 2, 2016: 2016 2015 Deferred tax (liabilities) assets: Net intangible assets $ $ Accelerated depreciation Net operating loss Investment in limited partnership Mining reclamation reserve Working capital (e.g., accrued compensation, prepaid assets) Net deferred tax assets Less valuation allowance Net deferred tax asset (liability) $ $ As of December 31, 2016, Summit Inc. had federal net operating loss carryforwards of $192.4 million, which expire between 2030 and 2036. In addition, Summit Inc. has alternative minimum tax credits of $0.2 million as of December 31, 2016, which do not expire. As of December 31, 2016 and January 2, 2016, Summit Inc. had a valuation allowance on net deferred tax assets of $502.8 million and $263.8 million, respectively. The deferred tax assets primarily relate to tax basis in intangible assets that exceeds book basis. The intangible asset tax basis was largely recognized as a result of the LP Unit exchanges in 2016 and 2015. Summit Inc. also has a deferred tax asset related to the expected taxable loss in 2016. The ultimate realization of deferred tax assets is dependent upon the generation of future taxable income during the periods in which those temporary differences become deductible and consideration of tax-planning strategies. Considering these factors, a partial valuation allowance was recorded, which has resulted in no deferred provision expense for Summit Holdings for the year ended December 31, 2016. 2016 2015 Valuation Allowance: Beginning balance $ $ Additional basis from exchanged LP Units Loss carryforwards Release of valuation allowance and other Ending balance $ $ The net deferred income tax asset (liability) as of December 31, 2016 and January 2, 2016 are included in other noncurrent liabilities and other assets, respectively, on the consolidated balance sheets. Tax Receivable Agreement —Upon the consummation of the Reorganization, the Company entered into a tax receivable agreement with the holders of LP Units and certain other pre-IPO owners (“Investor Entities”) that provides for the payment by Summit Inc. to exchanging holders of LP Units of 85% of the benefits, if any, that Summit Inc. is deemed to realize as a result of (i) increases in the tax basis of tangible and intangible assets of Summit Holdings and (ii) the utilization of certain net operating losses of the Investor Entities and certain other tax benefits related to entering into the tax receivable agreement, including tax benefits attributable to payments under the tax receivable agreement. For the years ended December 31, 2016 and January 2, 2016, 45,124,528 LP Units and 18,675,000 LP units, respectively, were acquired by Summit Inc. in exchange for an equal number of newly-issued shares of Summit Inc.’s Class A common stock. These exchanges resulted in deferred tax assets of approximately $769.7 million, 85% of which will be paid to the holders of the exchanged LP Units when the benefit is received by the Company. As discussed above, a partial valuation allowance was recognized on the net deferred tax asset that resulted from the tax receivable agreement. However, realization of approximately $69.7 million of the tax benefit was deemed probable as of December 31, 2016 for which a valuation allowance has not been recognized or was released in 2016. The Company considers all available evidence (both positive and negative), including continuing periods of income and other tax planning strategies, in determining whether realization of the tax benefit is more likely than not. The Company will continue to monitor facts and circumstances in the reassessment of the likelihood that the tax benefit will be realized. If this were to occur, the valuation allowance, or portion thereof, would be released with a corresponding charge to tax receivable agreement expense for the liability due to former LP Unit holders equal to 85% of the valuation allowance release. With regard to the $69.7 million realizable deferred tax asset associated with the tax receivable agreement, 85%, or $59.2 million, will be paid to former holders of LP Units. Approximately $58.1 million is included in other noncurrent liabilities and $1.1 million is in included in accrued expenses as of December 31, 2016 and $14.9 million was recognized as tax receivable agreement expense in the year ended December 31, 2016. Tax Distributions – The holders of Summit Holdings’ LP Units, including Summit Inc., incur U.S. federal, state and local income taxes on their share of any taxable income of Summit Holdings. The limited partnership agreement of Summit Holdings provides for pro rata cash distributions (“tax distributions”) to the holders of the LP Units in an amount generally calculated to provide each holder of LP Units with sufficient cash to cover its tax liability in respect of the LP Units. In general, these tax distributions are computed based on Summit Holdings’ estimated taxable income allocated to each holder of LP Units multiplied by an assumed tax rate equal to the highest effective marginal combined U.S. federal, state and local income tax rate applicable to an individual or corporate resident in New York, New York (or a corporate resident in certain circumstances). For the years ended December 31, 2016 and January 2, 2016, Summit Holdings paid tax distributions totaling $13.0 million and $28.7 million, respectively, to holders of its LP Units, other than Summit Inc. C Corporation Subsidiaries — The effective income tax rate for the C corporations differ from the statutory federal rate primarily due to (1) tax depletion expense in excess of the expense recorded under U.S. GAAP, (2) state income taxes and the effect of graduated tax rates and (3) various other items such as limitations on meals and entertainment and other costs. The effective income tax rate for the Canadian subsidiary is not significantly different from its historical effective tax rate. As of December 31, 2016, and January 2, 2016, Summit Inc. and its subsidiaries had not recognized any liabilities for uncertain tax positions. No material interest or penalties were recognized in income tax expense during the years ended December 31, 2016, January 2, 2016 or December 27, 2014. Tax years from 2013 to 2016 remain open and subject to audit by federal, Canadian, and state tax authorities.
Summit Materials, LLC
Income Taxes	(10) Income Taxes Summit LLC is a limited liability company and passes its tax attributes for federal and state tax purposes to its member and is generally not subject to federal or state income tax. However, certain subsidiaries, or subsidiary groups, file federal, state, and Canadian income tax returns due to their status as C corporations or laws within that jurisdiction. The provision for income taxes is primarily composed of federal, state and local income taxes for the subsidiary entities that have C corporation status. As of December 31, 2016 and January 2, 2016, the Company has not recognized any liabilities for uncertain tax positions. The Company records interest and penalties as a component of the income tax provision. No material interest or penalties were recognized in income tax expense during the years ended December 31, 2016 and January 2, 2016. For the years ended December 31, 2016, January 2, 2016 and December 27, 2014, income taxes consisted of the following: 2016 2015 2014 Provision for income taxes: Current $ $ $ Deferred Income tax benefit $ $ $ The effective tax rate on pre-tax income differs from the U.S. statutory rate of 35% due to the following: 2016 2015 2014 Income tax expense (benefit) at federal statutory tax rate $ $ $ Less: Income tax benefit at federal statutory tax rate for LLC entities State and local income taxes Permanent differences Effective tax rate change Valuation allowance — Other Income tax benefit $ $ $ The following table summarizes the components of the net deferred income tax liability as December 31, 2016 and January 2, 2016: 2016 2015 Deferred tax (liabilities) assets: Accelerated depreciation $ $ Net operating loss Investment in limited partnership Net intangible assets Mining reclamation reserve Working capital (e.g., accrued compensation, prepaid assets) Net deferred tax liabilities Less valuation allowance Net deferred tax laibility $ $ The net deferred income tax liability as of December 31, 2016 and January 2, 2016, are included in other noncurrent liabilities on the consolidated balance sheets. As of December 31, 2016, Summit LLC had federal net operating loss carryforwards of $72.6 million, which expire between 2030 and 2036. Summit LLC has alternative minimum tax credits of $0.2 million as of December 31, 2016, which do not expire. Valuation Allowance —The ultimate realization of deferred tax assets is dependent upon the generation of future taxable income during the periods in which those temporary differences become deductible (including the effect of available carryback and carryforward periods) and tax-planning strategies. The deferred income tax asset related to net operating losses resides with two separate tax paying subsidiaries (or subsidiary groups) of Summit LLC. These tax payers have historically generated taxable income and forecast to continue generating taxable income; however, the use of a portion of the net operating may be limited. Therefore, a $2.7 million and $2.5 million, respectively, valuation allowance has been recorded on a portion of the total net operating loss carryforwards as of December 31, 2016 and January 2, 2016, respectively. At December 31, 2016, the Company had net operating loss carryforwards for federal and state income tax purposes of $63.7 million and $72.5 million, respectively, which are available to offset future federal and state taxable income, if any, through 2035. Tax years from 2013 to 2016 remain open and subject to audit by federal, Canadian, and state tax authorities. No income tax expense or benefit was recognized in other comprehensive loss in 2016, 2015 or 2014. Tax Distributions – The holders of Summit Holdings’ LP Units, including Summit Inc., incur U.S. federal, state and local income taxes on their share of any taxable income of Summit Holdings. The limited partnership agreement of Summit Holdings provides for pro rata cash distributions (“tax distributions”) to the holders of the LP Units in an amount generally calculated to provide each holder of LP Units with sufficient cash to cover its tax liability in respect of the LP Units. In general, these tax distributions are computed based on Summit Holdings’ estimated taxable income allocated to each holder of LP Units multiplied by an assumed tax rate equal to the highest effective marginal combined U.S. federal, state and local income tax rate applicable to an individual or corporate resident in New York, New York (or a corporate resident in certain circumstances). In the years ended December 31, 2016 and January 2, 2016, Summit LLC paid distributions to Summit Holdings totaling $39.7 million and $46.6 million, respectively, of which $13.0 million and $28.7 million, respectively, was distributed to Summit Holdings’ partners, other than Summit Inc., and $26.7 million and $17.9 million, respectively, was paid to Summit Inc.

Employee Benefit Plans

Employee Benefit Plans	12 Months Ended
	Dec. 31, 2016
Employee Benefit Plans	(11) Employee Benefit Plans Defined Contribution Plan —The Company sponsors employee 401(k) savings plans for its employees, including certain union employees. The plans provide for various required and discretionary Company matches of employees’ eligible compensation contributed to the plans. The expense for the defined contribution plans was $8.6 million, $7.1 million and $3.8 million for the years ended December 31, 2016, January 2, 2016 and December 27, 2014, respectively. Defined Benefit and Other Postretirement Benefits Plans —The Company’s subsidiary, Continental Cement, sponsors two noncontributory defined benefit pension plans for hourly and salaried employees. The salaried plan is closed to new participants and benefits are frozen. The hourly plan is also frozen except that new hourly participants from the Davenport, Iowa location accrue new benefits in the hourly plan. Pension benefits for eligible hourly employees are based on a monthly pension factor for each year of credited service. Pension benefits for eligible salaried employees are generally based on years of service and average eligible compensation. Continental Cement also sponsors three unfunded healthcare and life insurance benefits plans for certain eligible retired employees. Effective January 1, 2014, the plan covering employees of the Hannibal, Missouri location was amended to eliminate all future retiree health and life coverage for current employees. During 2015, Continental Cement adopted two new unfunded healthcare and life insurance plans to provide benefits prior to Medicare eligibility for certain salaried and hourly employees of the Davenport, Iowa location. The funded status of the pension and other postretirement benefit plans is recognized in the consolidated balance sheets as the difference between the fair value of plan assets and the benefit obligations. For defined benefit pension plans, the benefit obligation is the projected benefit obligation (“PBO”) and for the healthcare and life insurance benefits plans, the benefit obligation is the accumulated postretirement benefit obligation (“APBO”). The PBO represents the actuarial present value of benefits expected to be paid upon retirement based on estimated future compensation levels. However, since the plans’ participants are not subject to future compensation increases, the plans’ PBO equals the APBO. The APBO represents the actuarial present value of postretirement benefits attributed to employee services already rendered. The fair value of plan assets represents the current market value of assets held by an irrevocable trust fund for the sole benefit of participants. The measurement of the benefit obligations are based on the Company’s estimates and actuarial valuations. These valuations reflect the terms of the plan and use participant-specific information, such as compensation, age and years of service, as well as certain assumptions that require significant judgment, including estimates of discount rates, expected return on plan assets, rate of compensation increases, interest-crediting rates and mortality rates. Effective in 2015, the Company uses December 31 as the measurement date for its defined benefit pension and other postretirement benefit plans. Obligations and Funded Status —The following information is as of December 31, 2016 and December 31, 2015 and for the years ended December 31, 2016, December 31, 2015 and December 27, 2014: 2016 2015 Pension Healthcare Pension Healthcare benefits & Life Ins. benefits & Life Ins. Change in benefit obligations: Beginning of period $ $ $ $ Service cost Interest cost Actuarial loss (gain) Change in plan provision — Benefits paid End of period Change in fair value of plan assets: Beginning of period $ $ — $ $ — Actual return on plan assets Employer contributions Benefits paid End of period — — Funded status of plans $ $ $ $ Current liabilities $ — $ $ — $ Noncurrent liabilities Liability recognized $ $ $ $ Amounts recognized in accumulated other comprehensive income: Net actuarial loss $ $ $ $ Prior service cost — — Total amount recognized $ $ $ $ The amount recognized in accumulated other comprehensive income (“AOCI”) is the actuarial loss and prior service cost, which has not yet been recognized in periodic benefit cost. At December 31, 2016, the actuarial loss expected to be amortized from AOCI to benefit cost in 2017 is $0.6 million and $0.1 million for the pension and postretirement obligations, respectively. 2016 2015 2014 Pension Healthcare Pension Healthcare Pension Healthcare benefits & Life Ins. benefits & Life Ins. benefits & Life Ins. Amounts recognized in other comprehensive (income) loss: Net actuarial gain (loss) $ $ $ $ $ $ Prior service cost — — — — Amortization of prior year service cost — — — Curtailment benefit — — — — — Amortization of gain Total amount recognized $ $ $ $ $ $ Components of net periodic benefit cost: Service cost $ $ $ $ $ $ Interest cost Amortization of gain Expected return on plan assets — — — Curtailments — — — — — Amortization of prior service credit — — — Net periodic benefit cost $ $ $ $ $ $ Assumptions— Weighted-average assumptions used to determine the benefit obligations as of year-end 2016 and 2015 are: 2016 2015 Healthcare Healthcare Pension benefits & Life Ins. Pension benefits & Life Ins. Discount rate 3.61% - 3.81% 3.32% - 3.65% 3.74% - 3.97% 3.34% - 3.80% Expected long-term rate of return on plan assets 7.00% N/A 7.30% N/A Weighted-average assumptions used to determine net periodic benefit cost for years ended December 31, 2016, January 2, 2016 and December 27, 2014: 2016 2015 2014 Healthcare Healthcare Healthcare Pension benefits & Life Ins. Pension benefits & Life Ins. Pension benefits & Life Ins. Discount rate 3.74% - 3.97% 3.34% - 3.80% 3.50% - 3.98% 3.39% - 3.52% 4.21% - 4.46% 4.33% Expected long-term rate of return on plan assets 7.30% N/A 7.30% N/A 7.50% N/A The expected long-term return on plan assets is based upon the Plans’ consideration of historical and forward-looking returns and the Company’s estimation of what a portfolio, with the target allocation described below, will earn over a long-term horizon. The discount rate is derived using the Citigroup Pension Discount Curve. Assumed health care cost trend rates were 8.0% grading to 4.5% as of year-end 2016 and 2015. Assumed health care cost trend rates have a significant effect on the amounts reported for the Company’s healthcare and life insurance benefits plans. A one percentage-point change in assumed health care cost trend rates would have the following effects as of year-end 2016 and 2015: 2016 2015 Increase Decrease Increase Decrease Total service cost and interest cost components $ $ $ $ APBO Plan Assets —The defined benefit pension plans’ (the “Plans”) investment strategy is to minimize investment risk while generating acceptable returns. The Plans currently invest a relatively high proportion of the plan assets in fixed income securities, while the remainder is invested in equity securities, cash reserves and precious metals. The equity securities are diversified into funds with growth and value investment strategies. The target allocation for plan assets is as follows: equity securities—30%; fixed income securities—63%; cash reserves—5%; and precious metals—2%. The Plans’ current investment allocations are within the tolerance of the target allocation. The Company had no Level 3 investments as of or for the years ended December 31, 2016 and January 2, 2016. At year-end 2016 and 2015, the Plans’ assets were invested predominantly in fixed-income securities and publicly traded equities, but may invest in other asset classes in the future subject to the parameters of the investment policy. The Plans’ investments in fixed-income assets include U.S. Treasury and U.S. agency securities and corporate bonds. The Plans’ investments in equity assets include U.S. and international securities and equity funds. The Company estimates the fair value of the Plans’ assets using various valuation techniques and, to the extent available, quoted market prices in active markets or observable market inputs. The descriptions and fair value methodologies for the Plans’ assets are as follows: Fixed Income Securities —Corporate and government bonds are classified as Level 2 assets, as they are either valued at quoted market prices from observable pricing sources at the reporting date or valued based upon comparable securities with similar yields and credit ratings. Equity Securities —Equity securities are valued at the closing market price reported on a U.S. exchange where the security is actively traded and are therefore classified as Level 1 assets. Cash —The carrying amounts of cash approximate fair value due to the short-term maturity. Precious Metals— Precious metals are valued at the closing market price reported on a U.S. exchange where the security is actively traded and are therefore classified as Level 1 assets. The fair value of the Plans’ assets by asset class and fair value hierarchy level as of December 31, 2016 and December 31, 2015 are as follows: 2016 Quoted prices in active Total fair markets for identical Observable value assets (Level 1) inputs (Level 2) Fixed income securities: Intermediate—government $ $ — $ Intermediate—corporate — Short-term—government — Short-term—corporate — Equity securities: — U.S. Large cap value — U.S. Large cap growth — U.S. Mid cap value — U.S. Mid cap growth — U.S. Small cap value — U.S. Small cap growth — Managed Futures International — Emerging Markets Commodities Broad Basket Cash — Precious metals — Total $ $ $ 2015 Quoted prices in active Total fair markets for identical Observable value assets (Level 1) inputs (Level 2) Fixed income securities: Intermediate—government $ $ — $ Intermediate—corporate — Short-term—government — Short-term—corporate — Equity securities: U.S. Large cap value — U.S. Large cap growth — U.S. Mid cap value — U.S. Mid cap growth — U.S. Small cap value — U.S. Small cap growth — International — Cash — Precious metals — Total $ $ $ Cash Flows —The Company expects to contribute approximately $1.7 million in 2017 to both its pension plans and to its healthcare and life insurance benefits plans. The estimated benefit payments for each of the next five years and the five-year period thereafter are as follows: Pension Healthcare and Life benefits Insurance Benefits 2017 $ $ 2018 2019 2020 2021 2022 - 2026
Summit Materials, LLC
Employee Benefit Plans	(11) Employee Benefit Plans Defined Contribution Plan —The Company sponsors employee 401(k) savings plans for its employees, including certain union employees. The plans provide for various required and discretionary Company matches of employees’ eligible compensation contributed to the plans. The expense for the defined contribution plans was $8.6 million, $7.1 million and $3.8 million for the years ended December 31, 2016, January 2, 2016 and December 27, 2014, respectively. Defined Benefit and Other Postretirement Benefits Plans —The Company’s subsidiary, Continental Cement, sponsors two noncontributory defined benefit pension plans for hourly and salaried employees. The salaried plan is closed to new participants and benefits are frozen. The hourly plan is also frozen except that new hourly participants from the Davenport, Iowa location accrue new benefits in the hourly plan. Pension benefits for eligible hourly employees are based on a monthly pension factor for each year of credited service. Pension benefits for eligible salaried employees are generally based on years of service and average eligible compensation. Continental Cement also sponsors three unfunded healthcare and life insurance benefits plans for certain eligible retired employees. Effective January 1, 2014, the plan covering employees of the Hannibal, Missouri location was amended to eliminate all future retiree health and life coverage for current employees. During 2015, Continental Cement adopted two new unfunded healthcare and life insurance plans to provide benefits prior to Medicare eligibility for certain salaried and hourly employees of the Davenport, Iowa location. The funded status of the pension and other postretirement benefit plans is recognized in the consolidated balance sheets as the difference between the fair value of plan assets and the benefit obligations. For defined benefit pension plans, the benefit obligation is the projected benefit obligation (“PBO”) and for the healthcare and life insurance benefits plans, the benefit obligation is the accumulated postretirement benefit obligation (“APBO”). The PBO represents the actuarial present value of benefits expected to be paid upon retirement based on estimated future compensation levels. However, since the plans’ participants are not subject to future compensation increases, the plans’ PBO equals the APBO. The APBO represents the actuarial present value of postretirement benefits attributed to employee services already rendered. The fair value of plan assets represents the current market value of assets held by an irrevocable trust fund for the sole benefit of participants. The measurement of the benefit obligations are based on the Company’s estimates and actuarial valuations. These valuations reflect the terms of the plan and use participant-specific information, such as compensation, age and years of service, as well as certain assumptions that require significant judgment, including estimates of discount rates, expected return on plan assets, rate of compensation increases, interest-crediting rates and mortality rates. Effective in 2015, the Company uses December 31 as the measurement date for its defined benefit pension and other postretirement benefit plans. Obligations and Funded Status —The following information is as of December 31, 2016 and December 31, 2015 and for the years ended December 31, 2016, December 31, 2015 and December 27, 2014: 2016 2015 Pension Healthcare Pension Healthcare benefits & Life Ins. benefits & Life Ins. Change in benefit obligations: Beginning of period $ $ $ $ Service cost Interest cost Actuarial loss (gain) Change in plan provision — Benefits paid End of period Change in fair value of plan assets: Beginning of period $ $ — $ $ — Actual return on plan assets Employer contributions Benefits paid End of period — — Funded status of plans $ $ $ $ Current liabilities $ — $ $ — $ Noncurrent liabilities Liability recognized $ $ $ $ Amounts recognized in accumulated other comprehensive income: Net actuarial loss $ $ $ $ Prior service cost — — Total amount recognized $ $ $ $ The amount recognized in accumulated other comprehensive income (“AOCI”) is the actuarial loss and prior service cost, which has not yet been recognized in periodic benefit cost. At December 31, 2016, the actuarial loss expected to be amortized from AOCI to periodic benefit cost in 2017 is $0.6 million and $0.1 million for the pension and postretirement obligations, respectively. 2016 2015 2014 Pension Healthcare Pension Healthcare Pension Healthcare benefits & Life Ins. benefits & Life Ins. benefits & Life Ins. Amounts recognized in other comprehensive (income) loss: Net actuarial gain (loss) $ $ $ $ $ $ Prior service cost — — — — Amortization of prior year service cost — — — Curtailment benefit — — — — — Amortization of gain Total amount recognized $ $ $ $ $ $ Components of net periodic benefit cost: Service cost $ $ $ $ $ $ Interest cost Amortization of gain Expected return on plan assets — — — Curtailments — — — — — Amortization of prior service credit — — — Net periodic benefit cost $ $ $ $ $ $ Assumptions— Weighted-average assumptions used to determine the benefit obligations as of year-end 2016 and 2015 are: 2016 2015 Healthcare Healthcare Pension benefits & Life Ins. Pension benefits & Life Ins. Discount rate 3.61% - 3.81% 3.32% - 3.65% 3.74% - 3.97% 3.34% - 3.80% Expected long-term rate of return on plan assets 7.00% N/A 7.30% N/A Weighted-average assumptions used to determine net periodic benefit cost for years ended December 31, 2016, January 2, 2016 and December 27, 2014: 2016 2015 2014 Healthcare Healthcare Healthcare Pension benefits & Life Ins. Pension benefits & Life Ins. Pension benefits & Life Ins. Discount rate 3.74% - 3.97% 3.34% - 3.80% 3.50% - 3.98% 3.39% - 3.52% 4.21% - 4.46% 4.33% Expected long-term rate of return on plan assets 7.30% N/A 7.30% N/A 7.50% N/A The expected long-term return on plan assets is based upon the Plans’ consideration of historical and forward-looking returns and the Company’s estimation of what a portfolio, with the target allocation described below, will earn over a long-term horizon. The discount rate is derived using the Citigroup Pension Discount Curve. Assumed health care cost trend rates were 8.0% grading to 4.5% as of year-end 2016 and 2015. Assumed health care cost trend rates have a significant effect on the amounts reported for the Company’s healthcare and life insurance benefits plans. A one percentage-point change in assumed health care cost trend rates would have the following effects as of year-end 2016 and 2015: 2016 2015 Increase Decrease Increase Decrease Total service cost and interest cost components $ $ $ $ APBO Plan Assets —The defined benefit pension plans’ (the “Plans”) investment strategy is to minimize investment risk while generating acceptable returns. The Plans currently invest a relatively high proportion of the plan assets in fixed income securities, while the remainder is invested in equity securities, cash reserves and precious metals. The equity securities are diversified into funds with growth and value investment strategies. The target allocation for plan assets is as follows: equity securities—30%; fixed income securities—63%; cash reserves—5%; and precious metals—2%. The Plans’ current investment allocations are within the tolerance of the target allocation. The Company had no Level 3 investments as of or for the years ended December 31, 2016 and January 2, 2016. At year-end 2016 and 2015, the Plans’ assets were invested predominantly in fixed-income securities and publicly traded equities, but may invest in other asset classes in the future subject to the parameters of the investment policy. The Plans’ investments in fixed-income assets include U.S. Treasury and U.S. agency securities and corporate bonds. The Plans’ investments in equity assets include U.S. and international securities and equity funds. The Company estimates the fair value of the Plans’ assets using various valuation techniques and, to the extent available, quoted market prices in active markets or observable market inputs. The descriptions and fair value methodologies for the Plans’ assets are as follows: Fixed Income Securities —Corporate and government bonds are classified as Level 2 assets, as they are either valued at quoted market prices from observable pricing sources at the reporting date or valued based upon comparable securities with similar yields and credit ratings. Equity Securities —Equity securities are valued at the closing market price reported on a U.S. exchange where the security is actively traded and are therefore classified as Level 1 assets. Cash —The carrying amounts of cash approximate fair value due to the short-term maturity. Precious Metals— Precious metals are valued at the closing market price reported on a U.S. exchange where the security is actively traded and are therefore classified as Level 1 assets. The fair value of the Plans’ assets by asset class and fair value hierarchy level as of December 31, 2016 and December 31, 2015 are as follows: 2016 Quoted prices in active Total fair markets for identical Observable value assets (Level 1) inputs (Level 2) Fixed income securities: Intermediate—government $ $ — $ Intermediate—corporate — Short-term—government — Short-term—corporate — Equity securities: — U.S. Large cap value — U.S. Large cap growth — U.S. Mid cap value — U.S. Mid cap growth — U.S. Small cap value — U.S. Small cap growth — Managed Futures International — Emerging Markets Commodities Broad Basket Cash — Precious metals — Total $ $ $ 2015 Quoted prices in active Total fair markets for identical Observable value assets (Level 1) inputs (Level 2) Fixed income securities: Intermediate—government $ $ — $ Intermediate—corporate — Short-term—government — Short-term—corporate — Equity securities: U.S. Large cap value — U.S. Large cap growth — U.S. Mid cap value — U.S. Mid cap growth — U.S. Small cap value — U.S. Small cap growth — International — Cash — Precious metals — Total $ $ $ Cash Flows —The Company expects to contribute approximately $1.7 million in 2017 to both its pension plans and to its healthcare and life insurance benefits plans. The estimated benefit payments for each of the next five years and the five-year period thereafter are as follows: Pension Healthcare and Life benefits Insurance Benefits 2017 $ $ 2018 2019 2020 2021 2022 - 2026

Accrued Mining and Landfill Rec

Accrued Mining and Landfill Reclamation	12 Months Ended
	Dec. 31, 2016
Accrued Mining and Landfill Reclamation	(12) Accrued Mining and Landfill Reclamation The Company has asset retirement obligations arising from regulatory or contractual requirements to perform certain reclamation activities at the time that certain quarries and landfills are closed, which are primarily included in other noncurrent liabilities on the consolidated balance sheets. The current portion of the liabilities, $5.1 million and $2.0 million as of December 31, 2016 and January 2, 2016, respectively, is included in accrued and other liabilities on the consolidated balance sheets. The total undiscounted anticipated costs for site reclamation as of December 31, 2016 and January 2, 2016 were $63.6 million and $56.7 million, respectively. The liabilities were initially measured at fair value and are subsequently adjusted for accretion expense, payments and changes in the amount or timing of the estimated cash flows. The corresponding asset retirement costs are capitalized as part of the carrying amount of the related long-lived asset and depreciated over the asset’s remaining useful life. The following table presents the activity for the asset retirement obligations for the years ended December 31, 2016 and January 2, 2016: 2016 2015 Beginning balance $ $ Acquired obligations Change in cost estimate Settlement of reclamation obligations Additional liabilities incurred — Accretion expense Ending balance $ $
Summit Materials, LLC
Accrued Mining and Landfill Reclamation	(12) Accrued Mining and Landfill Reclamation The Company has asset retirement obligations arising from regulatory or contractual requirements to perform certain reclamation activities at the time that certain quarries and landfills are closed, which are primarily included in other noncurrent liabilities on the consolidated balance sheets. The current portion of the liabilities, $5.1 million and $2.0 million as of December 31, 2016 and January 2, 2016, respectively, is included in accrued and other liabilities on the consolidated balance sheets. The total undiscounted anticipated costs for site reclamation as of December 31, 2016 and January 2, 2016 were $63.6 million and $56.7 million, respectively. The liabilities were initially measured at fair value and are subsequently adjusted for accretion expense, payments and changes in the amount or timing of the estimated cash flows. The corresponding asset retirement costs are capitalized as part of the carrying amount of the related long-lived asset and depreciated over the asset’s remaining useful life. The following table presents the activity for the asset retirement obligations for the years ended December 31, 2016 and January 2, 2016: 2016 2015 Beginning balance $ $ Acquired obligations Change in cost estimate Settlement of reclamation obligations Additional liabilities incurred — Accretion expense Ending balance $ $

Net Income Per Share

Net Income Per Share	12 Months Ended
	Dec. 31, 2016
Net Income Per Share
Net Income Per Share	(13) Earnings Per Share Basic earnings per share is computed by dividing net income attributable to Summit Inc. by the weighted average common shares outstanding and diluted earnings are computed by dividing net income attributable to Summit Inc., adjusted, as applicable, for net income attributable to Summit Holdings that would have been allocated to Summit Inc. as a result of the assumed conversion of LP Units, by the weighted-average common shares outstanding assuming dilution. The following table shows the calculation of basic income per share: 2016 2015 Net income attributable to Summit Inc. $ $ Weighted average shares of Class A shares outstanding Basic earnings per share $ $ Net income attributable to Summit Inc. $ $ Add: Noncontrolling interest impact of LP Unit conversion — Diluted net income attributable to Summit Inc. Weighted average shares of Class A shares outstanding Add: weighted average of LP Units — Add: stock options — Add: warrants Add: restricted stock units Add: performance stock units Weighted average dilutive shares outstanding Diluted earnings per share $ $ Excluded from diluted earnings per share for the year ended December 31, 2016 were 32,327,907 LP Units and for the year ended January 2, 2016 were 2,265,584 stock options as they were antidilutive. The weighted-average shares of Class A common stock for each period shown reflect retroactive application of 1,135,962 and 735,108 shares of Class A common stock issued as stock dividends in 2016 and 2015, respectively. Neither basic or diluted earnings per share include 10,000,000 shares of Class A common stock issued by Summit Inc. on January 10, 2017 (see note 23).

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2016
Commitments and Contingencies	(14) Commitments and Contingencies The Company is party to certain legal actions arising from the ordinary course of business activities. Accruals are recorded when the outcome is probable and can be reasonably estimated. While the ultimate results of claims and litigation cannot be predicted with certainty, management expects that the ultimate resolution of all pending or threatened claims and litigation will not have a material effect on the Company’s consolidated results of operations, financial position or liquidity. The Company records legal fees as incurred. Litigation and Claims— The Company is obligated under an indemnification agreement entered into with the sellers of Harper Contracting, Inc., Harper Sand and Gravel, Inc., Harper Excavating, Inc., Harper Ready Mix Company, Inc. and Harper Investments, Inc. for the sellers’ ownership interests in a joint venture agreement. The Company has the rights to any benefits under the joint venture as well as the assumption of any obligations, but does not own equity interests in the joint venture. The joint venture has incurred significant losses on a highway project in Utah, which have resulted in requests for funding from the joint venture partners and ultimately from the Company. Through December 31, 2016, the Company has funded $8.8 million, $4.0 million in 2012 and $4.8 million in 2011. In 2012 and 2011, the Company recognized losses on the indemnification agreement of $8.0 million and $1.9 million, respectively. As of December 31, 2016 and January 2, 2016, an accrual of $4.3 million was recorded in other noncurrent liabilities as management’s best estimate of future funding obligations. Environmental Remediation and Site Restoration— The Company’s operations are subject to and affected by federal, state, provincial and local laws and regulations relating to the environment, health and safety and other regulatory matters. These operations require environmental operating permits, which are subject to modification, renewal and revocation. The Company regularly monitors and reviews its operations, procedures and policies for compliance with these laws and regulations. Despite these compliance efforts, risk of environmental liability is inherent in the operation of the Company’s business, as it is with other companies engaged in similar businesses and there can be no assurance that environmental liabilities or noncompliance will not have a material adverse effect on the Company’s consolidated financial condition, results of operations or liquidity. Other— The Company is obligated under various firm purchase commitments for certain raw materials and services that are in the ordinary course of business. Management does not expect any significant changes in the market value of these goods and services during the commitment period that would have a material adverse effect on the financial condition, results of operations and cash flows of the Company. The terms of the purchase commitments generally approximate one year.
Summit Materials, LLC
Commitments and Contingencies	(13) Commitments and Contingencies The Company is party to certain legal actions arising from the ordinary course of business activities. Accruals are recorded when the outcome is probable and can be reasonably estimated. While the ultimate results of claims and litigation cannot be predicted with certainty, management expects that the ultimate resolution of all pending or threatened claims and litigation will not have a material effect on the Company’s consolidated results of operations, financial position or liquidity. The Company records legal fees as incurred. Litigation and Claims— The Company is obligated under an indemnification agreement entered into with the sellers of Harper Contracting, Inc., Harper Sand and Gravel, Inc., Harper Excavating, Inc., Harper Ready Mix Company, Inc. and Harper Investments, Inc. for the sellers’ ownership interests in a joint venture agreement. The Company has the rights to any benefits under the joint venture as well as the assumption of any obligations, but does not own equity interests in the joint venture. The joint venture has incurred significant losses on a highway project in Utah, which have resulted in requests for funding from the joint venture partners and ultimately from the Company. Through December 31, 2016, the Company has funded $8.8 million, $4.0 million in 2012 and $4.8 million in 2011. In 2012 and 2011, the Company recognized losses on the indemnification agreement of $8.0 million and $1.9 million, respectively. As of December 31, 2016 and January 2, 2016, an accrual of $4.3 million was recorded in other noncurrent liabilities as management’s best estimate of future funding obligations. Environmental Remediation and Site Restoration— The Company’s operations are subject to and affected by federal, state, provincial and local laws and regulations relating to the environment, health and safety and other regulatory matters. These operations require environmental operating permits, which are subject to modification, renewal and revocation. The Company regularly monitors and reviews its operations, procedures and policies for compliance with these laws and regulations. Despite these compliance efforts, risk of environmental liability is inherent in the operation of the Company’s business, as it is with other companies engaged in similar businesses and there can be no assurance that environmental liabilities or noncompliance will not have a material adverse effect on the Company’s consolidated financial condition, results of operations or liquidity. Other— The Company is obligated under various firm purchase commitments for certain raw materials and services that are in the ordinary course of business. Management does not expect any significant changes in the market value of these goods and services during the commitment period that would have a material adverse effect on the financial condition, results of operations and cash flows of the Company. The terms of the purchase commitments generally approximate one year.

Related Party Transactions

Related Party Transactions	12 Months Ended
	Dec. 31, 2016
Related Party Transactions	(15) Related Party Transactions Under the terms of a transaction and management fee agreement between Summit Holdings and Blackstone Management Partners L.L.C. (“BMP”), whose affiliates include controlling stockholders of the Company, BMP provided monitoring, advisory and consulting services to the Company through March 17, 2015. Under the terms of the agreement, BMP was permitted to assign, and had assigned, a portion of the fees to which it was entitled to Silverhawk Summit, L.P. and to certain other equity investors. The management fee was calculated based on the greater of $300,000 or 2.0% of the Company’s annual consolidated profit, as defined in the agreement, and is included in general and administrative expenses. In the year ended December 31, 2016, the Company recognized a $1.4 million benefit for an adjustment to costs accrued under this agreement and incurred management fees totaling $1.0 million and $4.4 million during the period between December 28, 2014 and March 17, 2015 and the year ended December 27, 2014, respectively. During these periods, the Company paid immaterial amounts to Silverhawk Summit, L.P. and to other equity investors. Also under the terms of the transaction and management fee agreement, BMP undertook financial and structural analysis, due diligence investigations, corporate strategy and other advisory services and negotiation assistance related to acquisitions for which the Company paid BMP transaction fees equal to 1.0% of the aggregate enterprise value of any acquired entity or, if such transaction was structured as an asset purchase or sale, 1.0% of the consideration paid for or received in respect of the assets acquired or disposed. The Company paid BMP $3.9 million during the year ended December 27, 2014. During these periods, the Company paid immaterial amounts to Silverhawk Summit, L.P. and to other equity investors. The acquisition-related fees paid pursuant to this agreement are included in transaction costs. In connection with the IPO, the transaction and management fee agreement with BMP was terminated on March 17, 2015 for a termination payment of $13.8 million; $13.4 million was paid to affiliates of BMP and the remaining $0.4 million was paid to affiliates of Silverhawk Summit, L.P. and to certain other equity investors. In addition to the transaction and management fees paid to BMP, the Company reimburses BMP for direct expenses incurred, which were not material in the years ended December 31, 2016, January 2, 2016 and December 27, 2014. Blackstone Advisory Partners L.P., an affiliate of BMP, served as an initial purchaser of $18.8 million of the 2022 Notes issued in March 2016 and $22.5 million and $26.3 million of the 2023 Notes issued in November 2015 and July 2015, respectively, and received compensation in connection therewith. In addition, Blackstone Advisory Partners L.P. served as an underwriter of 1,681,875 shares of Class A common stock issued in connection with the August 2015 follow-on offering and received compensation in connection therewith. On July 17, 2015, the Company purchased the Davenport Assets from Lafarge North America Inc. for a purchase price of $450.0 million in cash and a cement distribution terminal in Bettendorf, Iowa. At closing, $370.0 million of the purchase price was paid, and the remaining $80.0 million was paid on August 13, 2015. Summit Holdings entered into a commitment letter dated April 16, 2015, with Blackstone Capital Partners V L.P. (“BCP”) for equity financing up to $90.0 million in the form of a preferred equity interest (the “Equity Commitment Financing”), which would have been used to pay the $80.0 million deferred purchase price if other financing was not secured by December 31, 2015. For the Equity Commitment Financing, the Company paid a $1.8 million commitment fee to BCP for the year ended January 2, 2016. Cement sales to companies owned by certain noncontrolling members of Continental Cement were approximately $1.4 million, and $14.3 million for the period between December 28, 2014 and March 17, 2015 and the year ended December 27, 2014, respectively. In the year ended December 27, 2014, the Company sold certain assets associated with the production of concrete blocks, including inventory and equipment, to a related party for $2.3 million.
Summit Materials, LLC
Related Party Transactions	(14) Related Party Transactions Under the terms of a transaction and management fee agreement between Summit Holdings and Blackstone Management Partners L.L.C. (“BMP”), whose affiliates include controlling stockholders of the Company, BMP provided monitoring, advisory and consulting services to the Company through March 17, 2015. Under the terms of the agreement, BMP was permitted to assign, and had assigned, a portion of the fees to which it was entitled to Silverhawk Summit, L.P. and to certain other equity investors. The management fee was calculated based on the greater of $300,000 or 2.0% of the Company’s annual consolidated profit, as defined in the agreement, and is included in general and administrative expenses. In the year ended December 31, 2016, the Company recognized a $1.4 million benefit for an adjustment to costs accrued under this agreement and incurred management fees totaling $1.0 million and $4.4 million during the period between December 28, 2014 and March 17, 2015 and the year ended December 27, 2014, respectively. During these periods, the Company paid immaterial amounts to Silverhawk Summit, L.P. and to other equity investors. Also under the terms of the transaction and management fee agreement, BMP undertook financial and structural analysis, due diligence investigations, corporate strategy and other advisory services and negotiation assistance related to acquisitions for which the Company paid BMP transaction fees equal to 1.0% of the aggregate enterprise value of any acquired entity or, if such transaction was structured as an asset purchase or sale, 1.0% of the consideration paid for or received in respect of the assets acquired or disposed. The Company paid BMP $3.9 million during the year ended December 27, 2014. During these periods, the Company paid immaterial amounts to Silverhawk Summit, L.P. and to other equity investors. The acquisition-related fees paid pursuant to this agreement are included in transaction costs. In connection with the IPO, the transaction and management fee agreement with BMP was terminated on March 17, 2015 for a termination payment of $13.8 million; $13.4 million was paid to affiliates of BMP and the remaining $0.4 million was paid to affiliates of Silverhawk Summit, L.P. and to certain other equity investors. In addition to the transaction and management fees paid to BMP, the Company reimburses BMP for direct expenses incurred, which were not material in the years ended December 31, 2016, January 2, 2016 and December 27, 2014. Blackstone Advisory Partners L.P., an affiliate of BMP, served as an initial purchaser of $18.8 million of the 2022 Notes issued in March 2016 and $22.5 million and $26.3 million of the 2023 Notes issued in November 2015 and July 2015, respectively, and received compensation in connection therewith. In addition, Blackstone Advisory Partners L.P. served as an underwriter of 1,681,875 shares of Class A common stock issued in connection with the August 2015 follow-on offering and received compensation in connection therewith. On July 17, 2015, the Company purchased the Davenport Assets from Lafarge North America Inc. for a purchase price of $450.0 million in cash and a cement distribution terminal in Bettendorf, Iowa. At closing, $370.0 million of the purchase price was paid, and the remaining $80.0 million was paid on August 13, 2015. Summit Holdings entered into a commitment letter dated April 16, 2015, with Blackstone Capital Partners V L.P. (“BCP”) for equity financing up to $90.0 million in the form of a preferred equity interest (the “Equity Commitment Financing”), which would have been used to pay the $80.0 million deferred purchase price if other financing was not secured by December 31, 2015. For the Equity Commitment Financing, the Company paid a $1.8 million commitment fee to BCP for the year ended January 2, 2016. Cement sales to companies owned by certain noncontrolling members of Continental Cement were approximately $1.4 million, and $14.3 million for the period between December 28, 2014 and March 17, 2015 and the year ended December 27, 2014, respectively. In the year ended December 27, 2014, the Company sold certain assets associated with the production of concrete blocks, including inventory and equipment, to a related party for $2.3 million.

Acquisition-Related Liabilities

Acquisition-Related Liabilities	12 Months Ended
	Dec. 31, 2016
Acquisition-Related Liabilities	(16) Acquisition-Related Liabilities A number of acquisition-related liabilities have been recorded subject to terms in the relevant purchase agreements, including deferred consideration and noncompete payments. Noncompete payments have been accrued where certain former owners of newly acquired companies have entered into standard noncompete arrangements. Subject to terms and conditions stated in these noncompete agreements, payments are generally made over a five-year period. Deferred consideration is purchase price consideration paid in the future as agreed to in the purchase agreement and is not contingent on future events. Deferred consideration is generally scheduled to be paid in years ranging from 5 to 20 years in annual installments. The remaining payments due under these noncompete and deferred consideration agreements are as follows: 2017 2018 2019 2020 2021 Thereafter Total scheduled payments Present value adjustments Total noncompete obligations and deferred consideration $ Accretion on the deferred consideration and noncompete obligations is recorded in interest expense.
Summit Materials, LLC
Acquisition-Related Liabilities	(15) Acquisition-Related Liabilities A number of acquisition-related liabilities have been recorded subject to terms in the relevant purchase agreements, including deferred consideration and noncompete payments. Noncompete payments have been accrued where certain former owners of newly acquired companies have entered into standard noncompete arrangements. Subject to terms and conditions stated in these noncompete agreements, payments are generally made over a five-year period. Deferred consideration is purchase price consideration paid in the future as agreed to in the purchase agreement and is not contingent on future events. Deferred consideration is generally scheduled to be paid in years ranging from 5 to 20 years in annual installments. The remaining payments due under these noncompete and deferred consideration agreements are as follows: 2017 2018 2019 2020 2021 Thereafter Total scheduled payments Present value adjustments Total noncompete obligations and deferred consideration $ Accretion on the deferred consideration and noncompete obligations is recorded in interest expense.

Supplemental Cash Flow Informat

Supplemental Cash Flow Information	12 Months Ended
	Dec. 31, 2016
Supplemental Cash Flow Information	(17) Supplemental Cash Flow Information Supplemental cash flow information for the years ended December 31, 2016, January 2, 2016 and December 27, 2014 was as follows: 2016 2015 2014 Cash payments: Interest $ $ $ Income taxes Non cash financing activities: Purchase of noncontrolling interest in Continental Cement $ — $ $ — Stock Dividend — Exchange of LP units to shares of Class A — —
Summit Materials, LLC
Supplemental Cash Flow Information	(16) Supplemental Cash Flow Information Supplemental cash flow information for the years ended December 31, 2016, January 2, 2016 and December 27, 2014 was as follows: 2016 2015 2014 Cash payments: Interest $ $ $ Income taxes Non cash financing activities: Purchase of noncontrolling interest in Continental Cement $ — $ $ —

Leasing Arrangements

Leasing Arrangements	12 Months Ended
	Dec. 31, 2016
Leasing Arrangements	(18) Leasing Arrangements Rent expense, which primarily relates to land, plants and equipment, during the years ended December 31, 2016, January 2, 2016 and December 27, 2014 was $18.6 million, $12.1 million and $5.5 million, respectively. The Company has lease agreements associated with quarry facilities under which royalty payments are made. The payments are generally based on tons sold in a particular period; however, certain agreements have minimum annual payments. Royalty expense recorded in cost of revenue during the years ended December 31, 2016, January 2, 2016 and December 27, 2014 was $15.6 million, $12.6 million and $9.0 million, respectively. Minimum contractual commitments for the subsequent five years under long-term operating leases and under royalty agreements are as follows: Operating Royalty Leases Agreements 2017 $ $ 2018 2019 2020 2021
Summit Materials, LLC
Leasing Arrangements	(17) Leasing Arrangements Rent expense, which primarily relates to land, plants and equipment, during the years ended December 31, 2016, January 2, 2016 and December 27, 2014 was $18.6 million, $12.1 million and $5.5 million, respectively. The Company has lease agreements associated with quarry facilities under which royalty payments are made. The payments are generally based on tons sold in a particular period; however, certain agreements have minimum annual payments. Royalty expense recorded in cost of revenue during the years ended December 31, 2016, January 2, 2016 and December 27, 2014 was $15.6 million, $12.6 million and $9.0 million, respectively. Minimum contractual commitments for the subsequent five years under long-term operating leases and under royalty agreements are as follows: Operating Royalty Leases Agreements 2017 $ $ 2018 2019 2020 2021

Redeemable Noncontrolling Inter

Redeemable Noncontrolling Interest	12 Months Ended
	Dec. 31, 2016
Redeemable Noncontrolling Interest	(19) Redeemable Noncontrolling Interest On March 17, 2015, upon the consummation of the IPO and the transactions contemplated by a contribution and purchase agreement entered into with the holders of all of the outstanding Class B Units of Continental Cement, Continental Cement became a wholly-owned indirect subsidiary of Summit Inc. The noncontrolling interests of Continental Cement were acquired for aggregate consideration of $64.1 million, consisting of $35.0 million of cash, 1,029,183 shares of Summit Inc.’s Class A common stock and $15.0 million aggregate principal amount of non-interest bearing notes payable in six annual installments of $2.5 million, beginning on March 17, 2016. Prior to the March 17, 2015 purchase of the noncontrolling interest, the Company owned 100 Class A Units of Continental Cement, which represented an approximately 70% economic interest and had a preference in liquidation to the Class B Units. Continental Cement issued 100,000,000 Class B Units in May 2010, which remained outstanding until March 17, 2015 and represented an approximately 30% economic interest.
Summit Materials, LLC
Redeemable Noncontrolling Interest	(18) Redeemable Noncontrolling Interest On March 17, 2015, upon the consummation of the IPO and the transactions contemplated by a contribution and purchase agreement entered into with the holders of all of the outstanding Class B Units of Continental Cement, Continental Cement became a wholly-owned indirect subsidiary of Summit Inc. The noncontrolling interests of Continental Cement were acquired for aggregate consideration of $64.1 million, consisting of $35.0 million of cash, 1,029,183 shares of Summit Inc.’s Class A common stock and $15.0 million aggregate principal amount of non-interest bearing notes payable in six annual installments of $2.5 million, beginning on March 17, 2016. Prior to the March 17, 2015 purchase of the noncontrolling interest, the Company owned 100 Class A Units of Continental Cement, which represented an approximately 70% economic interest and had a preference in liquidation to the Class B Units. Continental Cement issued 100,000,000 Class B Units in May 2010, which remained outstanding until March 17, 2015 and represented an approximately 30% economic interest.

Employee Long Term Incentive Pl

Employee Long Term Incentive Plan	12 Months Ended
	Dec. 31, 2016
Employee Long Term Incentive Plan	(20) Employee Long Term Incentive Plan Prior to the IPO and Reorganization, the capital structure of Summit Holdings consisted of six different classes of limited partnership interests (Class A-1, Class A-2, Class B-1, Class C, Class D-1 and Class D-2), each of which was subject to unique distribution rights. There were no outstanding Class A-2 interests as of the date of Reclassification (as defined below). A portion, but not all, of the Class D-1 and D-2 units were vested. As of their respective grant date, approximately half of the Class D-1 units were subject to a vesting period of five years (“time-vesting interests”), 20% on the first anniversary of the grant date and the remaining 80% vested monthly over a period of four years following the first anniversary date. Approximately half of the D-1 units and all of the D-2 units vested upon Summit Holdings’ investors achieving certain investment returns (“performance-vesting interests”). The fair value of the time-vesting Class D units granted in 2014 totaled $0.6 million. The weighted-average grant-date fair value in 2014 was $1,368. In connection with the IPO and the Reorganization, the limited partnership agreement of Summit Holdings was amended and restated to, among other things, modify its capital structure by creating the LP Units (“Reclassification”). Immediately following the Reclassification, 69,007,297 LP Units were outstanding, of which 575,256 time-vesting interests were not fully vested and 2,425,361 performance-vesting interests were not vested. In addition, in substitution for part of the economic benefit of the Class C and Class D interests that was not reflected in the conversion of such interests to LP Units, warrants were issued to holders of Class C interests to purchase an aggregate of 160,333 shares of Class A common stock, and options were issued to holders of Class D interests to purchase an aggregate of 4,358,842 shares of Class A common stock (“leverage restoration options”). The exercise price of the warrants and leverage restoration options is the IPO price of $18.00 per share. In conjunction with the Reclassification of the equity-based awards, the Company recognized a $14.5 million modification charge in general and administrative expenses in the year ended January 2, 2016. The leverage restoration options were granted under the Summit Materials, Inc. 2015 Omnibus Incentive Plan (the “Omnibus Incentive Plan”). The leverage restoration options that correlated to time-vesting interests vest over four years beginning on the Reclassification date and the leverage restoration options that correlated to performance-vesting interests vest when both the applicable return multiple is achieved and a four year time-vesting condition is satisfied. The four-year time-vesting condition will be satisfied with respect to 25% on each of the first four anniversaries of the Reclassification date, subject to the employee’s continued employment through the applicable vesting date. The Company also granted 240,000 options to purchase shares of Class A common stock under the Omnibus Incentive Plan to certain employees some of whom had not previously been granted equity-based interests. These stock options have an exercise price of $18.00 per share, the IPO price, and are subject to a time-based vesting condition that will be satisfied with respect to 25% of the award on each of the first four anniversaries of the grant date, subject to the employee’s continued employment through the applicable vesting date. The weighted-average grant date fair value of all stock options granted in 2015 was $9.00 per stock option. In the year ended December 31, 2016, Summit Inc. acquired 45,124,528 LP Units in exchange for an equal number of shares of Class A common stock, of which 37,933,804 LP Units were exchanged by certain investment funds associated with or designated by The Blackstone Group L.P. (“Blackstone”). Blackstone subsequently sold the shares of Class A common stock it received through underwritten public offerings. As a result of these transactions and Blackstone’s prior exchange and sale of LP Units, the performance target associated with certain LP Units and leverage restoration options which was based on Blackstone receiving a 1.75 times return on its initial investment, was achieved, which had historically been considered improbable for accounting purposes. In addition, on August 9, 2016, the Board of Directors of Summit Inc. determined that it was in the best interest of the Company to waive the 3.0 times threshold on the remaining unvested performance-based LP Units and leverage restoration options. The waiver of the 3.0 times threshold was accounted for as a modification of the applicable LP Units and stock options whereby the performance metric was previously considered improbable and became probable with the modification. The fair value of the LP Units was based on the closing stock price of Summit Inc.’s shares of Class A common stock on the modification date and the fair value of the affected options was determined using the Black-Scholes, Merton model, which requires the input of subjective assumptions, including the expected volatility and the expected term. The assumptions used included the $18.00 exercise price, 1.55% risk-free interest rate, no dividend yield, a 48% volatility rate and expected term of approximately 9 years. The Company recognized $37.3 million in general and administrative expenses in the year ended December 31, 2016 related to the vesting of these performance-based awards, which does not include expense on the stock options that will be recognized over the remaining 4-year vesting period. As of December 31, 2016 and January 2, 2016, 190,020 and 411,727 respectively, of time-vesting LP Units were unvested and 187,879 vested during the year ended December 31, 2016. In 2016, 2,822,259 stock options, 363,800 restricted stock units and 130,691 performance stock units were granted. Excluding 34,928 restricted stock units that have a one-year vesting period, these awards vest over three years at a rate of 33.3% of the award on each of the first three anniversaries, subject to the employee’s continued employment through the applicable vesting date. These stock options have an exercise price between $17.07 per share and $21.63 per share. In 2015, 10,000 restricted stock units were granted at a weighted-average grant date fair value of $23.79 per restricted stock unit, which vest over four years at a rate of 25% of the award on each of the first four anniversaries, subject to the employee’s continued employment through the applicable vesting date. The fair value of restricted stock units was determined based on the closing stock price of Summit Inc.’s Class A common shares on the date of grant. The outstanding warrants, restricted stock units and options granted have a ten year contractual term at which point any unexercised awards are cancelled. As of December 31, 2016, 5,473,736 awards have been granted under the Omnibus Incentive Plan of the 13,500,000 shares of Class A common stock authorized for issuance. The following table summarizes information for the equity awards granted in 2016: Options Restricted Stock Units Performance Stock Units Warrants Weighted Weighted Weighted Weighted average grant- Number of average grant- Number of average grant- Number of average grant- Number of date fair value restricted date fair value performance date fair value performance date fair value options per unit stock units per unit stock units per unit stock units per unit Beginning balance—January 2, 2016 $ $ — $ — $ Granted — — Forfeited — — — — Exercised — — — — — — Vested — — — — — — Balance—December 31, 2016 $ $ $ $ The fair value of the time-vesting options granted in 2016 and 2015 was estimated as of the grant date using the Black-Scholes-Merton model, which requires the input of subjective assumptions, including the expected volatility and the expected term. The fair value of the performance stock units granted in 2016 and the Class D units granted in 2014 was estimated as of the grant date using Monte Carlo simulations, which requires the input of subjective assumptions, including the expected volatility and the expected term. The following table presents the weighted average assumptions used to estimate the fair value of grants in 2016, 2015 and 2014: Performance Options Stock Units 2016 2015 2014 2016 Risk-free interest rate 1.75% - 1.97% 1.68% - 1.92% 0.50% - 0.68% 0.88% Dividend yield None None None None Volatility 48% 50% 58% 37% Expected term 10 Years 7 - 10 years 3 - 4 Years 3 Years The risk-free rate is based on the yield at the date of grant of a U.S. Treasury security with a maturity period approximating the expected term. As Summit Holdings has not historically and does not plan to issue regular dividends, a dividend yield of zero was used. The volatility assumption is based on reported data of a peer group of publically traded companies for which historical information was available adjusted for the Company’s capital structure. The expected term is based on expectations about future exercises and represents the period of time that the units granted are expected to be outstanding. Compensation expense for time-vesting interests granted is based on the grant date fair value. The Company recognizes compensation costs on a straight-line basis over the service period, which is generally the vesting period of the award. Forfeitures are recognized as they occur. Share-based compensation expense, which is recognized in general and administrative expenses, totaled $49.9 million, $19.9 million and $2.2 million in the years ended December 31, 2016, January 2, 2016 and December 27, 2014, respectively. As of December 31, 2016, unrecognized compensation cost totaled $29.9 million. The weighted average remaining contractual term over which the unrecognized compensation cost is to be recognized is 2.8 years as of year-end 2016. As of December 31, 2016, the intrinsic value of outstanding options, restricted stock units and performance stock units was $29.2 million, $8.4 million and $3.1 million, respectively, and the remaining contractual term was 8.3 years, 9.2 years and 9.2 years, respectively. The weighted average strike price of stock options outstanding as of December 31, 2016 was $17.94 per share. At December 31, 2016, the intrinsic value of stock options exercised and restricted stock units vested were both $0.1 million. The intrinsic value of 1.1 million exercisable stock options as of December 31, 2016 was $6.4 million with a weighted average strike price of $18.03 and a weighted average remaining vesting period of 8.2 years.
Summit Materials, LLC
Employee Long Term Incentive Plan	(19) Employee Long Term Incentive Plan Prior to the IPO and Reorganization, the capital structure of Summit Holdings consisted of six different classes of limited partnership interests (Class A-1, Class A-2, Class B-1, Class C, Class D-1 and Class D-2), each of which was subject to unique distribution rights. There were no outstanding Class A-2 interests as of the date of the Reclassification (as defined below). A portion, but not all, of the Class D-1 and D-2 units were vested. As of their respective grant date, approximately half of the Class D-1 units were subject to a vesting period of five years (“time-vesting interests”), 20% on the first anniversary of the grant date and the remaining 80% vested monthly over a period of four years following the first anniversary date. Approximately half of the D-1 units and all of the D-2 units vested upon Summit Holdings’ investors achieving certain investment returns (“performance-vesting interests”). The fair value of the time-vesting Class D units granted in 2014 totaled $0.6 million. The weighted-average grant-date fair value in 2014 was $1,368. In connection with the IPO and the Reorganization, the limited partnership agreement of Summit Holdings was amended and restated to, among other things, modify its capital structure by creating the LP Units (“Reclassification”). Immediately following the Reclassification, 69,007,297 LP Units were outstanding, of which 575,256 time-vesting interests were not fully vested and 2,425,361 performance-vesting interests were not vested. In addition, in substitution for part of the economic benefit of the Class C and Class D interests that was not reflected in the conversion of such interests to LP Units, warrants were issued to holders of Class C interests to purchase an aggregate of 160,333 shares of Class A common stock, and options were issued to holders of Class D interests to purchase an aggregate of 4,358,842 shares of Class A common stock (“leverage restoration options”). The exercise price of the warrants and leverage restoration options is the IPO price of $18.00 per share. In conjunction with the Reclassification of the equity-based awards, the Company recognized a $14.5 million modification charge in general and administrative expenses in the year ended January 2, 2016. The leverage restoration options were granted under the Summit Materials, Inc. 2015 Omnibus Incentive Plan (the “Omnibus Incentive Plan”). The leverage restoration options that correlated to time-vesting interests vest over four years beginning on the Reclassification date and the leverage restoration options that correlated to performance-vesting interests vest when both the applicable return multiple is achieved and a four year time-vesting condition is satisfied. The four-year time-vesting condition will be satisfied with respect to 25% on each of the first four anniversaries of the Reclassification date, subject to the employee’s continued employment through the applicable vesting date. The Company also granted 240,000 options to purchase shares of Class A common stock under the Omnibus Incentive Plan to certain employees some of whom had not previously been granted equity-based interests. These stock options have an exercise price of $18.00 per share, the IPO price, and are subject to a time-based vesting condition that will be satisfied with respect to 25% of the award on each of the first four anniversaries of the grant date, subject to the employee’s continued employment through the applicable vesting date. The weighted-average grant date fair value of all stock options granted in 2015 was $9.00 per stock option. In the year ended December 31, 2016, Summit Inc. acquired 45,124,528 LP Units in exchange for an equal number of shares of Class A common stock, of which 37,933,804 LP Units were exchanged by certain investment funds associated with or designated by The Blackstone Group L.P. (“Blackstone”). Blackstone subsequently sold the shares of Class A common stock it received through underwritten public offerings. As a result of these transactions and Blackstone’s prior exchange and sale of LP Units, the performance target associated with certain LP Units and leverage restoration options which was based on Blackstone receiving a 1.75 times return on its initial investment, was achieved, which had historically been considered improbable for accounting purposes. In addition, on August 9, 2016, the Board of Directors of Summit Inc. determined that it was in the best interest of the Company to waive the 3.0 times threshold on the remaining unvested performance-based LP Units and leverage restoration options. The waiver of the 3.0 times threshold was accounted for as a modification of the applicable LP Units and stock options whereby the performance metric was previously considered improbable and became probable with the modification. The fair value of the LP Units was based on the closing stock price of Summit Inc.’s shares of Class A common stock on the modification date and the fair value of the affected options was determined using the Black-Scholes, Merton model, which requires the input of subjective assumptions, including the expected volatility and the expected term. The assumptions used included the $18.00 exercise price, 1.55% risk-free interest rate, no dividend yield, a 48% volatility rate and expected term of approximately 9 years. The Company recognized $37.3 million in general and administrative expenses in the year ended December 31, 2016 related to the vesting of these performance-based awards, which does not include expense on the stock options that will be recognized over the remaining 4-year vesting period. As of December 31, 2016 and January 2, 2016, 190,020 and 411,727 respectively, of time-vesting LP Units were unvested and 187,879 vested during the year ended December 31, 2016 In 2016, 2,822,259 stock options, 363,800 restricted stock units and 130,691 performance stock units were granted. Excluding 34,928 restricted stock units that have a one-year vesting period, these awards vest over three years at a rate of 33.3% of the award on each of the first three anniversaries, subject to the employee’s continued employment through the applicable vesting date. These stock options have an exercise price between $17.07 per share and $21.63 per share. In 2015, 10,000 restricted stock units were granted at a weighted-average grant date fair value of $23.79 per restricted stock unit, which vest over four years at a rate of 25% of the award on each of the first four anniversaries, subject to the employee’s continued employment through the applicable vesting date. The fair value of restricted stock units was determined based on the closing stock price of Summit Inc.’s Class A common shares on the date of grant. The outstanding warrants, restricted stock units and options granted have a ten year contractual term at which point any unexercised awards are cancelled. As of December 31, 2016, 5,473,736 awards have been granted under the Omnibus Incentive Plan of the 13,500,000 shares of Class A common stock authorized for issuance. The following table summarizes information for the equity awards granted in 2016: Options Restricted Stock Units Performance Stock Units Warrants Weighted Weighted Weighted Weighted average grant- Number of average grant- Number of average grant- Number of average grant- Number of date fair value restricted date fair value performance date fair value performance date fair value options per unit stock units per unit stock units per unit stock units per unit Beginning balance—January 2, 2016 $ $ — $ — $ Granted — — Forfeited — — — — Exercised — — — — — — Vested — — — — — — Balance—December 31, 2016 $ $ $ $ The fair value of the time-vesting options granted in 2016 and 2015 was estimated as of the grant date using the Black-Scholes-Merton model, which requires the input of subjective assumptions, including the expected volatility and the expected term. The fair value of the performance stock units granted in 2016 and the Class D units granted in 2014 was estimated as of the grant date using Monte Carlo simulations, which requires the input of subjective assumptions, including the expected volatility and the expected term. The following table presents the weighted average assumptions used to estimate the fair value of grants in 2016, 2015 and 2014: Performance Options Stock Units 2016 2015 2014 2016 Risk-free interest rate 1.75% - 1.97% 1.68% - 1.92% 0.50% - 0.68% 0.88% Dividend yield None None None None Volatility 48% 50% 58% 37% Expected term 10 Years 7 - 10 years 3 - 4 Years 3 Years The risk-free rate is based on the yield at the date of grant of a U.S. Treasury security with a maturity period approximating the expected term. As Summit Holdings has not historically and does not plan to issue regular dividends, a dividend yield of zero was used. The volatility assumption is based on reported data of a peer group of publically traded companies for which historical information was available adjusted for the Company’s capital structure. The expected term is based on expectations about future exercises and represents the period of time that the units granted are expected to be outstanding. Compensation expense for time-vesting interests granted is based on the grant date fair value. The Company recognizes compensation costs on a straight-line basis over the service period, which is generally the vesting period of the award. Forfeitures are recognized as they occur. Share-based compensation expense, which is recognized in general and administrative expenses, totaled $49.9 million, $19.9 million and $2.2 million in the years ended December 31, 2016, January 2, 2016 and December 27, 2014, respectively. As of December 31, 2016, unrecognized compensation cost totaled $29.9 million. The weighted average remaining contractual term over which the unrecognized compensation cost is to be recognized is 2.8 years as of year-end 2016. As of December 31, 2016, the intrinsic value of outstanding options, restricted stock units and performance stock units was $29.2 million, $8.4 million and $3.1 million, respectively, and the remaining contractual term was 8.3 years, 9.2 years and 9.2 years, respectively. The weighted average strike price of stock options outstanding as of December 31, 2016 was $17.94 per share. At December 31, 2016, the intrinsic value of stock options exercised and restricted stock units vested were both $0.1 million. The intrinsic value of 1.1 million exercisable stock options as of December 31, 2016 was $6.4 million with a weighted average strike price of $18.03 and a weighted average remaining vesting period of 8.2 years.

Segment Information

Segment Information	12 Months Ended
	Dec. 31, 2016
Segment Information	(21) Segment Information The Company has three operating segments: West; East; and Cement, which are its reporting segments. These segments are consistent with the Company’s management reporting structure. The operating results of each segment are regularly reviewed and evaluated by the Chief Executive Officer, the Company’s Chief Operating Decision Maker (“CODM”). The CODM primarily evaluates the performance of its segments and allocates resources to them based on a segment profit metric that we call Adjusted EBITDA, which is computed as earnings from continuing operations before interest, taxes, depreciation, depletion, amortization, accretion, share-based compensation, and transaction costs, as well as various other non-recurring, non-cash amounts. The West and East segments have several acquired subsidiaries that are engaged in various activities including quarry mining, aggregate production and contracting. The Cement segment is engaged in the production of Portland cement. Assets employed by each segment include assets directly identified with those operations. Corporate assets consist primarily of cash, property, plant and equipment for corporate operations and other assets not directly identifiable with a reportable business segment. The accounting policies applicable to each segment are consistent with those used in the consolidated financial statements. The following tables display selected financial data for the Company’s reportable business segments as of and for the years ended December 31, 2016, January 2, 2016 and December 27, 2014: 2016 2015 2014 Revenue*: West $ $ $ East Cement Total revenue $ $ $ * Intercompany sales are immaterial and the presentation above only reflects sales to external customers. 2016 2015 2014 Adjusted EBITDA: West $ $ $ East Cement Corporate and other Total Adjusted EBITDA Interest expense Depreciation, depletion and amortization Accretion IPO/ Legacy equity modification costs — Loss on debt financings — — Tax receivable agreement expense — — Transaction costs Management fees and expenses Non-cash compensation (Gain) loss on disposal and impairment of assets Other Income (loss) from continuing operations before taxes $ $ $ 2016 2015 2014 Purchases of property, plant and equipment West $ $ $ East Cement Total reportable segments Corporate and other Total purchases of property, plant and equipment $ $ $ 2016 2015 2014 Depreciation, depletion, amortization and accretion: West $ $ $ East Cement Total reportable segments Corporate and other Total depreciation, depletion, amortization and accretion $ $ $ 2016 2015 2014 Total assets: West $ $ $ East Cement Total reportable segments Corporate and other Total $ $ $ 2016 2015 2014 Revenue by product*: Aggregates $ $ $ Cement Ready-mix concrete Asphalt Paving and related services Other Total revenue $ $ $ * Revenue from the liquid asphalt terminals is included in asphalt revenue.
Summit Materials, LLC
Segment Information	(20) Segment Information The Company has three operating segments: West; East; and Cement, which are its reporting segments. These segments are consistent with the Company’s management reporting structure. The operating results of each segment are regularly reviewed and evaluated by the Chief Executive Officer, the Company’s Chief Operating Decision Maker (“CODM”). The CODM primarily evaluates the performance of its segments and allocates resources to them based on a segment profit metric that we call Adjusted EBITDA, which is computed as earnings from continuing operations before interest, taxes, depreciation, depletion, amortization, accretion, share-based compensation, and transaction costs, as well as various other non-recurring, non-cash amounts. The West and East segments have several acquired subsidiaries that are engaged in various activities including quarry mining, aggregate production and contracting. The Cement segment is engaged in the production of Portland cement. Assets employed by each segment include assets directly identified with those operations. Corporate assets consist primarily of cash, property, plant and equipment for corporate operations and other assets not directly identifiable with a reportable business segment. The accounting policies applicable to each segment are consistent with those used in the consolidated financial statements. The following tables display selected financial data for the Company’s reportable business segments as of and for the years ended December 31, 2016, January 2, 2016 and December 27, 2014: 2016 2015 2014 Revenue*: West $ $ $ East Cement Total revenue $ $ $ * Intercompany sales are immaterial and the presentation above only reflects sales to external customers. 2016 2015 2014 Adjusted EBITDA: West $ $ $ East Cement Corporate and other Total Adjusted EBITDA Interest expense Depreciation, depletion and amortization Accretion IPO/ Legacy equity modification costs — Loss on debt financings — — Transaction costs Management fees and expenses Non-cash compensation (Gain) loss on disposal and impairment of assets Other Income (loss) from continuing operations before taxes $ $ $ 2016 2015 2014 Purchases of property, plant and equipment West $ $ $ East Cement Total reportable segments Corporate and other Total purchases of property, plant and equipment $ $ $ 2016 2015 2014 Depreciation, depletion, amortization and accretion: West $ $ $ East Cement Total reportable segments Corporate and other Total depreciation, depletion, amortization and accretion $ $ $ 2016 2015 2014 Total assets: West $ $ $ East Cement Total reportable segments Corporate and other Total $ $ $ 2016 2015 2014 Revenue by product*: Aggregates $ $ $ Cement Ready-mix concrete Asphalt Paving and related services Other Total revenue $ $ $ *

Supplementary Data (Unaudited)

Supplementary Data (Unaudited)	12 Months Ended
	Dec. 31, 2016
Supplementary Data (Unaudited)	(22) Supplementary Data (Unaudited) Supplemental financial information (unaudited) by quarter is shown below for the years ended December 31, 2016 and January 2, 2016. The basic and diluted earnings per share amounts for each period shown reflect retroactive application of 1,135,962 and 735,108 shares of Class A common stock issued as stock dividends in 2016 and 2015, respectively. 2016 2015 4Q 3Q 2Q 1Q 4Q 3Q 2Q 1Q Net revenue $ $ $ $ $ $ $ $ Operating income (loss) Income (loss) from continuing operations Net income (loss) Net income (loss) attributable to Summit Inc. Basic earnings per share attributable to Summit Inc. Diluted earnings per share attributable to Summit Inc.
Summit Materials, LLC
Supplementary Data (Unaudited)	(22) Supplementary Data (Unaudited) Supplemental financial information (unaudited) by quarter is as follows for the years ended January 2, 2016 and December 27, 2014: 2016 2015 4Q 3Q 2Q 1Q 4Q 3Q 2Q 1Q Net revenue $ $ $ $ $ $ $ $ Operating income (loss) Income (loss) from continuing operations Net income (loss)

Subsequent Events

Subsequent Events	12 Months Ended
	Dec. 31, 2016
Subsequent Events	(23) Subsequent Events On January 10, 2017, Summit Inc. raised $237.6 million, net of underwriting discounts, through the issuance of 10,000,000 shares of Class A common stock at a public offering price of $24.05 per share. Summit Inc. used these proceeds to purchase an equal number of LP Units and intends to cause Summit Holdings to use a portion of the proceeds from the offering to acquire two materials-based companies for a combined purchase price of approximately $110 million in cash, with remaining net proceeds to be used for general corporate purposes, which may include, but is not limited to, funding acquisitions, repaying indebtedness, capital expenditures and funding working capital. On January 19, 2017, Summit LLC entered into Amendment No. 1 (“Amendment No. 1”) to the Credit Agreement, which, among other things, reduced the applicable margin in respect of the $640.3 million outstanding principal amount of term loans thereunder and included a 1.00% prepayment premium in connection with certain further repricing events that occur on or prior to the six-month anniversary of the effective date of Amendment No. 1. All other material terms and provisions remain substantially identical to the terms and provisions in place immediately prior to the effectiveness of Amendment No. 1.
Summit Materials, LLC
Subsequent Events	(23) Subsequent Events On January 10, 2017, Summit Inc. raised $237.6 million, net of underwriting discounts, through the issuance of 10,000,000 shares of Class A common stock at a public offering price of $24.05 per share. Summit Inc. used these proceeds to purchase an equal number of LP Units and intends to cause Summit Holdings to use a portion of the proceeds from the offering to acquire two materials-based companies for a combined purchase price of approximately $110 million in cash, with remaining net proceeds to be used for general corporate purposes, which may include, but is not limited to, funding acquisitions, repaying indebtedness, capital expenditures and funding working capital. On January 19, 2017, Summit LLC entered into Amendment No. 1 (“Amendment No. 1”) to the Credit Agreement, which, among other things, reduced the applicable margin in respect of the $640.3 million outstanding principal amount of term loans thereunder and included a 1.00% prepayment premium in connection with certain further repricing events that occur on or prior to the six-month anniversary of the effective date of Amendment No. 1. All other material terms and provisions remain substantially identical to the terms and provisions in place immediately prior to the effectiveness of Amendment No. 1.

Senior Notes' Guarantor and Non

Senior Notes' Guarantor and Non-Guarantor Financial Information	12 Months Ended
	Dec. 31, 2016
Summit Materials, LLC
Senior Notes' Guarantor and Non-Guarantor Financial Information	(21) Senior Notes’ Guarantor and Non-Guarantor Financial Information Summit LLC’s domestic wholly-owned subsidiary companies other than Finance Corp. are named as guarantors (collectively, the “Guarantors”) of the Senior Notes. Certain other partially-owned subsidiaries and a non-U.S. entity do not guarantee the Senior Notes (collectively, the “Non-Guarantors”). The Guarantors provide a joint and several, full and unconditional guarantee of the Senior Notes. There are no significant restrictions on Summit LLC’s ability to obtain funds from any of the Guarantor Subsidiaries in the form of dividends or loans. Additionally, there are no significant restrictions on a Guarantor Subsidiary’s ability to obtain funds from Summit LLC or its direct or indirect subsidiaries. The following condensed consolidating balance sheets, statements of operations and cash flows are provided for the Issuers, the Wholly-owned Guarantors and the Non-Guarantors. On March 17, 2015, the noncontrolling interests of Continental Cement were purchased resulting in Continental Cement being a wholly-owned indirect subsidiary of Summit LLC. Continental Cement’s results of operations and cash flows are reflected with the Guarantors for the year ended December 31, 2016. In 2014, Continental Cement’s results are shown separately as a Non Wholly-owned Guarantor. Earnings from subsidiaries are included in other income in the condensed consolidated statements of operations below. The financial information may not necessarily be indicative of the financial position, results of operations or cash flows had the guarantor or non-guarantor subsidiaries operated as independent entities. Condensed Consolidating Balance Sheets December 31, 2016 100% Owned Non- Issuers Guarantors Guarantors Eliminations Consolidated Assets Current assets: Cash and cash equivalents $ $ $ $ $ Accounts receivable, net — Intercompany receivables — — Cost and estimated earnings in excess of billings — — Inventories — — Other current assets — Total current assets Property, plant and equipment, net — Goodwill — — Intangible assets, net — — — Other assets Total assets $ $ $ $ $ Liabilities and Member’s Interest Current liabilities: Current portion of debt $ $ — $ — $ — $ Current portion of acquisition-related liabilities — — Accounts payable Accrued expenses Intercompany payables — Billings in excess of costs and estimated earnings — — Total current liabilities Long-term debt — — — Acquisition-related liabilities — — — Other noncurrent liabilities Total liabilities Total member's interest Total liabilities and member’s interest $ $ $ $ $ Condensed Consolidating Balance Sheets January 2, 2016 100% Owned Non- Issuers Guarantors Guarantors Eliminations Consolidated Assets Current assets: Cash and cash equivalents $ $ $ $ $ Accounts receivable, net Intercompany receivables — Cost and estimated earnings in excess of billings — — Inventories — — Other current assets — Total current assets Property, plant and equipment, net — Goodwill — — Intangible assets, net — — Other assets Total assets $ $ $ $ $ Liabilities and Member’s Interest Current liabilities: Current portion of debt $ $ — $ — $ — $ Current portion of acquisition-related liabilities — — Accounts payable Accrued expenses Intercompany payables — Billings in excess of costs and estimated earnings — — Total current liabilities Long-term debt — — — Acquisition-related liabilities — — — Other noncurrent liabilities Total liabilities Total member's interest Total liabilities and member’s interest $ $ $ $ $ Condensed Consolidating Statements of Operations and Comprehensive Loss Year ended December 31, 2016 100% Owned Non- Issuers Guarantors Guarantors Eliminations Consolidated Revenue $ — $ Cost of revenue (excluding items shown separately below) — General and administrative expenses — Depreciation, depletion, amortization and accretion — Operating (loss) income — Other (income) loss, net Interest expense — Income from continuing operations before taxes Income tax (benefit) expense — — Income from continuing operations Income from discontinued operations — — — — — Net income Net income attributable to noncontrolling interest — — — Net income attributable to member of Summit Materials, LLC $ $ $ $ $ Comprehensive income attributable to member of Summit Materials, LLC $ $ $ $ $ Condensed Consolidating Statements of Operations and Comprehensive Loss Year ended January 2, 2016 100% Owned Non- Issuers Guarantors Guarantors Eliminations Consolidated Revenue $ — $ $ $ $ Cost of revenue (excluding items shown separately below) — General and administrative expenses — Depreciation, depletion, amortization and accretion — Operating (loss) income — Other (income) expense, net Interest expense — Income from continuing operations before taxes Income tax (benefit) expense — — Income from operations Income from discontinued operations — — — Net income Net loss attributable to noncontrolling interest — — — Net income attributable to member of Summit Materials, LLC $ $ $ $ $ Comprehensive (loss) income attributable to member of Summit Materials, LLC $ $ $ $ $ Condensed Consolidating Statements of Operations and Comprehensive Loss Year ended December 27, 2014 Non- Wholly- 100% owned Owned Non- Issuers Guarantor Guarantors Guarantors Eliminations Consolidated Revenue $ — $ $ $ $ $ Cost of revenue (excluding items shown separately below) — General and administrative expenses — Depreciation, depletion, amortization and accretion — Operating (loss) income — Other income, net Interest expense (Loss) income from continuing operations before taxes Income tax (benefit) expense — — (Loss) income from operations Income from discontinued operations — — — — Net (loss) income Net income attributable to noncontrolling interest — — — — Net (loss) income attributable to member of Summit Materials, LLC $ $ $ $ $ $ Comprehensive (loss) income attributable to member of Summit Materials, LLC $ $ $ $ $ $ Condensed Consolidating Statements of Cash Flows For the year ended December 31, 2016 100% Owned Non- Issuers Guarantors Guarantors Eliminations Consolidated Net cash (used in) provided by operating activities $ $ $ $ — $ Cash flow from investing activities: Acquisitions, net of cash acquired — — Purchase of property, plant and equipment — Proceeds from the sale of property, plant, and equipment — — Other — — — Net cash used for investing activities — Cash flow from financing activities: Proceeds from investment by member — — Capital issuance costs — — — Net proceeds from debt issuance — — — Loans received from and payments made on loans from other Summit Companies — Payments on long-term debt — — Payments on acquisition-related liabilities — — Financing costs — — — Distributions from partnership — — — Other — — — Net cash provided by financing activities Impact of cash on foreign currency — — — Net (decrease) increase in cash Cash — Beginning of period Cash — End of period $ $ $ $ $ Condensed Consolidating Statements of Cash Flows For the year ended January 2, 2016 100% Owned Non- Issuers Guarantors Guarantors Eliminations Consolidated Net cash (used in) provided by operating activities $ $ $ $ $ Cash flow from investing activities: Acquisitions, net of cash acquired — — — Purchase of property, plant and equipment — Proceeds from the sale of property, plant, and equipment — — Other — — — Net cash used for investing activities — Cash flow from financing activities: Proceeds from investment by member — — Capital issuance costs — — — Net proceeds from debt issuance — — — Loans received from and payments made on loans from other Summit Companies — Payments on long-term debt — Payments on acquisition-related liabilities — — Financing costs — — — Distributions from partnership — — — Other — — — Net cash provided by (used for) financing activities Impact of cash on foreign currency — — — Net increase (decrease) in cash Cash — Beginning of period Cash — End of period $ $ $ $ $ Condensed Consolidating Statements of Cash Flows For the year ended December 27, 2014 Non- Wholly- 100% owned Owned Non- Issuers Guarantor Guarantors Guarantors Eliminations Consolidated Net cash (used in) provided by operating activities $ $ $ $ $ $ Cash flow from investing activities: Acquisitions, net of cash acquired — — — Purchase of property, plant and equipment — Proceeds from the sale of property, plant, and equipment — — — Other — — Net cash used for investing activities Cash flow from financing activities: Proceeds from investment by member — — Net proceeds from debt issuance — — — — Loans received from and payments made on loans from other Summit Companies — Payments on long-term debt — — Payments on acquisition-related liabilities — — — Financing costs — — — — Other — — Net cash provided by (used for) financing activities Impact of cash on foreign currency — — — — Net increase (decrease) in cash Cash — Beginning of period Cash — End of period $ $ $ $ $ $

Summary of Organization and S32

Summary of Organization and Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2016
Company Information
Initial Public Offering	Equity Offerings —Summit Inc. commenced operations on March 11, 2015 upon the pricing of the initial public offering of its Class A common stock (“IPO”). Summit Inc. raised $433.0 million, net of underwriting discounts, through the issuance of 25,555,555 shares of Class A common stock at a public offering price of $18.00 per share. Summit Inc. used the offering proceeds to purchase a number of newly-issued Class A Units (“LP Units”) from Summit Holdings equal to the number of shares of Class A common stock issued to the public. Summit Inc. caused Summit Holdings to use these proceeds: (i) to redeem $288.2 million in aggregate principal amount of outstanding 10 1 / 2 % senior notes due January 31, 2020 (“2020 Notes”); (ii) to purchase 71,428,571 Class B Units of Continental Cement Company, L.L.C. (“Continental Cement”); (iii) to pay a one-time termination fee of $13.8 million in connection with the termination of a transaction and management fee agreement with Blackstone Capital Partners V L.P.; and (iv) for general corporate purposes. The $288.2 million redemption of 2020 Notes was completed at a redemption price equal to par plus an applicable premium of $38.2 million plus $5.2 million of accrued and unpaid interest. In connection with the IPO, Summit Inc. issued 69,007,297 shares of its Class B common stock to Summit Owner Holdco LLC (“Summit Owner Holdco”), a Delaware limited liability company owned by certain pre-IPO owners and the former holders of Class B Units of Continental Cement. The Class B common stock entitled Summit Owner Holdco, without regard to the number of shares of Class B common stock held by it, to a number of votes that is equal to the aggregate number of LP Units held by all limited partners of Summit Holdings (excluding Summit Inc.). On July 19, 2016, Summit Owner Holdco transferred 28,661,526 shares of its Class B common stock to certain holders of LP Units and the remaining 40,345,771 shares of Class B common stock were cancelled. The Class B common stock entitles holders thereof, who are also holders of LP Units, with a number of votes that is equal to the number of LP Units they hold. The Class B common stock does not participate in dividends and does not have any liquidation rights.
Follow-On Offering	On August 11, 2015, Summit Inc. raised $555.8 million, net of underwriting discounts, through the issuance of 22,425,000 shares of Class A common stock at a public offering price of $25.75 per share ("the August 2015 follow-on offering"). Summit Inc. used these proceeds to purchase 3,750,000 newly-issued LP Units from Summit Holdings and 18,675,000 LP Units from certain pre-IPO owners, at a purchase price per LP Unit equal to the public offering price per share of Class A common stock, less underwriting discounts and commissions. Summit Holdings used the proceeds from the 3,750,000 newly-issued LP Units to pay the deferred purchase price of $80.0 million related to the July 17, 2015 acquisition of a cement plant and quarry in Davenport, Iowa, and seven cement terminals along the Mississippi River (the “Davenport Assets”) and for general corporate purposes.
Principles of Consolidation	Principles of Consolidation —The consolidated financial statements include the accounts of Summit Inc. and its majority owned subsidiaries. All intercompany balances and transactions have been eliminated. As a result of the Reorganization, Summit Holdings became a variable interest entity over which Summit Inc. has 100% voting power and control and for which Summit Inc. has the obligation to absorb losses and the right to receive benefits. As a result, Summit Inc. is Summit Holdings’ primary beneficiary and thus consolidates Summit Holdings in its consolidated financial statements with a corresponding noncontrolling interest elimination, which was 5.1% and 50.3% as of December 31, 2016 and January 2, 2016, respectively. Noncontrolling interests in consolidated subsidiaries represent a 20% ownership in Ohio Valley Asphalt, LLC and, prior to the IPO and concurrent purchase of the noncontrolling interests of Continental Cement, a 30% redeemable ownership in Continental Cement. The Company attributes consolidated stockholders’ equity and net income separately to the controlling and noncontrolling interests. The Company accounts for investments in entities for which it has an ownership of 20% to 50% using the equity method of accounting. The Company’s fiscal year is based on a 52-53 week year with each quarter composed of 13 weeks ending on a Saturday. The 53-week year occurs approximately once every seven years and occurred in 2015. The additional week in the 53-week year was included in the fourth quarter of 2015.
Use of Estimates	Use of Estimates —Preparation of these consolidated financial statements in conformity with U.S. generally accepted accounting principles (“U.S. GAAP”) requires management to make estimates and assumptions. These estimates and the underlying assumptions affect the amounts of assets and liabilities reported, disclosures about contingent assets and liabilities and reported amounts of revenue and expenses. Such estimates include the valuation of accounts receivable, inventories, valuation of deferred tax assets, goodwill, intangibles and other long-lived assets, pension and other postretirement obligations, and asset retirement obligations. Estimates also include revenue earned on contracts and costs to complete contracts. Most of the Company’s paving and related services are performed under fixed unit-price contracts with state and local governmental entities. Management regularly evaluates its estimates and assumptions based on historical experience and other factors, including the current economic environment. As future events and their effects cannot be determined with precision, actual results can differ significantly from estimates made. Changes in estimates, including those resulting from continuing changes in the economic environment, are reflected in the Company’s consolidated financial statements when the change in estimate occurs.
Business and Credit Concentrations	Business and Credit Concentrations— The Company’s operations are conducted primarily across 21 U.S. states and in British Columbia, Canada, with the most significant revenue generated in Texas, Kansas, Utah and Missouri . The Company’s accounts receivable consist primarily of amounts due from customers within these areas. Therefore, collection of these accounts is dependent on the economic conditions in the aforementioned states, as well as specific situations affecting individual customers. Credit granted within the Company’s trade areas has been granted to many customers and management does not believe that a significant concentration of credit exists with respect to any individual customer or group of customers. No single customer accounted for more than 10% of the Company’s total revenue in 2016, 2015 or 2014.
Accounts Receivable	Accounts Receivable —Accounts receivable are stated at the amount management expects to collect from outstanding balances. Management provides for probable uncollectible amounts through a charge to earnings and a credit to a valuation allowance based on its assessment of the collectability of individual accounts. In establishing the allowance, management considers historical losses adjusted to take into account current market conditions and its customers’ financial condition, the amount of receivables in dispute, the current receivables aging and current payment terms. Balances that remain outstanding after reasonable collection efforts are exercised are written off through a charge to the valuation allowance. The balances billed but not paid by customers, pursuant to retainage provisions included in contracts, are generally due upon completion of the contracts.
Revenue and Cost Recognition	Revenue and Cost Recognition —Revenue for product sales are recognized when evidence of an arrangement exists, the fee is fixed or determinable, title passes, which is generally when the product is shipped, and collection is reasonably assured. Product revenue includes sales of aggregates, cement and other materials to customers, net of discounts, allowances or taxes, as applicable. Revenue from construction contracts are included in service revenue and are recognized under the percentage-of-completion accounting method. The percent complete is measured by the cost incurred to date compared to the estimated total cost of each project. This method is used as management considers expended cost to be the best available measure of progress on these contracts, the majority of which are completed within one year, but may occasionally extend beyond one year. Inherent uncertainties in estimating costs make it at least reasonably possible that the estimates used will change within the near term and over the life of the contracts. Contract costs include all direct material and labor costs and those indirect costs related to contract performance and completion. Provisions for estimated losses on uncompleted contracts are made in the period in which such losses are estimable. General and administrative costs are charged to expense as incurred. Changes in job performance, job conditions and estimated profitability, including those arising from contract penalty provisions and final contract settlements, may result in revisions to costs and income. Such revisions are recognized in the period in which they are determined. An amount equal to contract costs incurred that are attributable to claims is included in revenue when realization is probable and the amount can be reliably estimated. Costs and estimated earnings in excess of billings are composed principally of revenue recognized on contracts (on the percentage-of-completion method) for which billings had not been presented to customers because the amount were not billable under the contract terms at the balance sheet date. In accordance with the contract terms, the unbilled receivables at December 31, 2016 will be billed in 2017. Billings in excess of costs and estimated earnings represent billings in excess of revenue recognized. Revenue from the receipt of waste fuels is classified as service revenue and is based on fees charged for the waste disposal, which are recognized when the waste is accepted.
Inventories	Inventories —Inventories consist of stone that has been removed from quarries and processed for future sale, cement, raw materials and finished concrete blocks. Inventories are valued at the lower of cost or market and are accounted for on a first-in first-out basis or an average cost basis. If items become obsolete or otherwise unusable or if quantities exceed what is projected to be sold within a reasonable period of time, they will be charged to costs of production in the period that the items are designated as obsolete or excess inventory. Stripping costs are costs of removing overburden and waste material to access aggregate materials and are recognized in cost of revenue in the same period as the revenue from the sale of the inventory.
Property, Plant and Equipment, net	Property, Plant and Equipment, net —Property, plant and equipment are recorded at cost, less accumulated depreciation, depletion and amortization. Expenditures for additions and improvements that significantly add to the productive capacity or extend the useful life of an asset are capitalized. Repair and maintenance costs that do not substantially expand productive capacity or extend the life of property, plant and equipment are expensed as incurred. Landfill airspace is included in property, plant and equipment at cost and is amortized based on the portion of the airspace used during the period compared to the gross estimated value of available airspace, which is updated periodically as circumstances dictate. Management reassesses the landfill airspace capacity with any changes in value recorded in cost of revenue. Capitalized landfill costs include expenditures for the acquisition of land and related airspace, engineering and permitting costs, cell construction costs and direct site improvement costs. Upon disposal of an asset, the cost and related accumulated depreciation are removed from the Company’s accounts and any gain or loss is included in general and administrative expenses. Depreciation on property, plant and equipment, including assets subject to capital leases, is generally computed on a straight-line basis. Depletion of mineral reserves is computed based on the portion of the reserves used during the period compared to the gross estimated value of proven and probable reserves, which is updated periodically as circumstances dictate. Leasehold improvements are amortized on a straight-line basis over the lesser of the asset’s useful life or the remaining lease term. The estimated useful lives are generally as follows: Buildings and improvements 10 - 30 years Plant, machinery and equipment 15 - 20 years Office equipment 3 - 7 years Truck and auto fleet 5 - 8 years Mobile equipment and barges 6 - 8 years Landfill airspace and improvements 10 - 30 years Other 4 - 20 years The Company reviews the carrying value of property, plant and equipment for impairment whenever events or circumstances indicate that the carrying value of an asset may not be recoverable from the estimated future cash flows expected to result from its use and eventual disposition. Such indicators may include, among others, deterioration in general economic conditions, adverse changes in the markets in which an entity operates, increases in input costs that have a negative effect on earnings and cash flows or a trend of negative or declining cash flows over multiple periods. Property, plant and equipment is tested for impairment at the lowest level for which identifiable cash flows are largely independent of the cash flows of other assets. As a result, the property, plant and equipment impairment test is at a significantly lower level than the level at which goodwill is tested for impairment. In markets where the Company does not produce downstream products, such as ready-mix concrete, asphalt paving mix and paving and related services, the lowest level of largely independent identifiable cash flows is at the individual aggregates operation or a group of aggregates operations collectively serving a local market or the cement operations. Conversely, in vertically-integrated markets, the cash flows of the downstream and upstream businesses are not largely independently identifiable and the vertically-integrated operations are considered the lowest level of largely independent identifiable cash flows. Assets are assessed for impairment charges when identified for disposition. Projected losses from disposition are recognized in the period in which they become estimable, which may be in advance of the actual disposition. The net gain (loss) from asset dispositions recognized in general and administrative expenses in fiscal years 2016, 2015 and 2014 was $6.8 million, $23.5 million and ($2.6 million), respectively. No material impairment charges have been recognized on assets held for use in 2016, 2015 or 2014. The losses are commonly a result of the cash flows expected from selling the asset being less than the expected cash flows that could be generated from holding the asset for use.
Accrued Mining and Landfill Reclamation	Accrued Mining and Landfill Reclamation —The mining reclamation reserve and financial commitments for landfill closure and post-closure activities are based on management’s estimate of future cost requirements to reclaim property at both currently operating and closed sites. Estimates of these obligations have been developed based on management’s interpretation of current requirements and proposed regulatory changes and are intended to approximate fair value. Costs are estimated in current dollars, inflated until the expected time of payment, using an inflation rate of 2.5%, and then discounted back to present value using a credit-adjusted, risk-free rate on obligations of similar maturity, adjusted to reflect the Company’s credit rating. Changes in the credit-adjusted, risk-free rate do not change recorded liabilities. However, subsequent increases in the recognized obligations are measured using a current credit-adjusted, risk-free rate. Decreases in the recognized obligations are measured at the initial credit-adjusted, risk-free rate. Significant changes in inflation rates or the amount or timing of future cost estimates typically result in both (1) a current adjustment to the recorded liability (and corresponding adjustment to the asset) and (2) a change in accretion of the liability and depreciation of the asset to be recorded prospectively over the remaining capacity of the unmined quarry or landfill.
Intangible Assets	Intangible Assets —The Company’s intangible assets are primarily composed of lease agreements and reserve rights. The assets related to lease agreements reflect the submarket royalty rates paid under agreements, primarily, for extracting aggregates. The values were determined as of the respective acquisition dates by a comparison of market-royalty rates to contract-royalty rates. The reserve rights relate to aggregate reserves to which the Company has the rights of ownership, but do not own the reserves. The intangible assets are amortized on a straight-line basis over the lives of the leases. The following table shows intangible assets by type and in total: December 31, 2016 January 2, 2016 Gross Net Gross Net Carrying Accumulated Carrying Carrying Accumulated Carrying Amount Amortization Amount Amount Amortization Amount Leases $ $ $ $ $ $ Reserve rights Trade names Other Total intangible assets $ $ $ $ $ $ Amortization expense in 2016, 2015 and 2014 was $2.6 million, $2.2 million and $0.9 million, respectively. The estimated amortization expense for intangible assets for each of the next five years and thereafter is as follows: 2017 $ 2018 2019 2020 2021 Thereafter Total $
Goodwill	Goodwill —Goodwill represents the purchase price paid in excess of the fair value of net tangible and intangible assets acquired. Goodwill recorded in connection with the Company’s acquisitions is primarily attributable to the expected profitability, assembled workforces of the acquired businesses and the synergies expected to arise after the Company’s acquisition of those businesses. Goodwill is not amortized, but is tested annually for impairment as of the first day of the fourth quarter and at any time that events or circumstances indicate that goodwill may be impaired. A qualitative approach may first be applied to determine whether it is more likely than not that the estimated fair value of a reporting unit is less than its carrying amount. If, as a result of the qualitative assessment, it is determined that an impairment is more likely than not, the two-step quantitative impairment test is then performed, otherwise further analysis is not required. The two-step impairment test first identifies potential goodwill impairment for each reporting unit and then, if necessary, measures the amount of the impairment loss.
Income Taxes	Income Taxes —Summit Inc. is a corporation subject to income taxes in the United States. Certain subsidiaries, including Summit Holdings, or subsidiary groups of the Company are taxable separate from Summit Inc. The provisions, or Summit Inc.’s proportional share of the provision, are included in the Company’s consolidated financial statements. The Company’s deferred income tax assets and liabilities are computed for differences between the tax basis and financial statement amounts that will result in taxable or deductible amounts in the future. The computed deferred balances are based on enacted tax laws and applicable rates for the periods in which the differences are expected to affect taxable income. A valuation allowance is recognized for deferred tax assets if it is more likely than not that some portion or all of the net deferred tax assets will not be realized. In making such a determination, all available positive and negative evidence is considered, including future reversals of existing taxable temporary differences, projected future taxable income, tax-planning strategies, and results of recent operations. If the Company determines it would be able to realize its deferred tax assets for which a valuation allowance had been recorded then an adjustment would be made to the deferred tax asset valuation allowance, which would reduce the provision for income taxes. The Company evaluates the tax positions taken on income tax returns that remain open and positions expected to be taken on the current year tax returns to identify uncertain tax positions. Unrecognized tax benefits on uncertain tax positions are recorded on the basis of a two-step process in which (1) the Company determines whether it is more likely than not that the tax positions will be sustained on the basis of the technical merits of the position and (2) for those tax positions that meet the more-likely-than-not recognition threshold, the largest amount of tax benefit that is more than 50 percent likely to be realized is recognized. Interest and penalties related to unrecognized tax benefits are recorded in income tax expense.
Earnings per Share	Earnings per Share— The Company computes basic earnings per share attributable to stockholders by dividing income attributable to Summit Inc. by the weighted-average shares of Class A common stock outstanding. Diluted earnings per share reflects the potential dilution beyond shares for basic earnings per share that could occur if securities or other contracts to issue common stock were exercised, converted into common stock, or resulted in the issuance of common stock that would have shared in the Company’s earnings. Since the Class B common stock has no economic value, those shares are not included in the weighted-average common share amount for basic or diluted earnings per share. In addition, as the shares of Class A common stock are issued by Summit Inc., the earnings and equity interests of noncontrolling interests are not included in basic earnings per share.
Fair Value Measurements	Fair Value Measurements— Certain acquisitions made by the Company require the payment of contingent amounts of purchase consideration. These payments are contingent on specified operating results being achieved in periods subsequent to the acquisition and will only be made if earn-out thresholds are achieved. Contingent consideration obligations are measured at fair value each reporting period. Any adjustments to fair value are recognized in earnings in the period identified. The Company has entered into interest rate derivatives on $200.0 million of its term loan borrowings to add stability to interest expense and to manage its exposure to interest rate movements. The effective portion of changes in the fair value of derivatives designated and that qualify as cash flow hedges is recorded in accumulated other comprehensive income and will be subsequently reclassified into earnings in the period that the hedged forecasted transaction affects earnings. The fair value of contingent consideration and derivatives as of December 31, 2016 and January 2, 2016 was: 2016 2015 Current portion of acquisition-related liabilities and Accrued expenses: Contingent consideration $ $ Cash flow hedges Acquisition-related liabilities and Other noncurrent liabilities Contingent consideration $ $ Cash flow hedges The fair value accounting guidance establishes the following fair value hierarchy that prioritizes the inputs used to measure fair value: Level 1 — Unadjusted quoted prices for identical assets or liabilities in active markets. Level 2 — Inputs other than Level 1 that are based on observable market data, either directly or indirectly. These include quoted prices for similar assets or liabilities in active markets, quoted prices for identical assets or liabilities in inactive markets, inputs that are observable that are not prices and inputs that are derived from or corroborated by observable markets. Level 3 — Valuations developed from unobservable data, reflecting the Company’s own assumptions, which market participants would use in pricing the asset or liability. The fair value of contingent consideration was based on unobservable, or Level 3, inputs, including projected probability-weighted cash payments and an 11.0% discount rate, which reflects a market discount rate. Changes in fair value may occur as a result of a change in actual or projected cash payments, the probability weightings applied by the Company to projected payments or a change in the discount rate. Significant increases or decreases in any of these inputs in isolation could result in a lower, or higher, fair value measurement. The fair value of the cash flow hedges are based on observable, or Level 2, inputs such as interest rates, bond yields and prices in inactive markets. There were no material adjustments to the fair value of contingent consideration in 2015 or to cash flow hedges in 2016 or 2015. In 2016, a $6.1 million increase in the fair value of contingent consideration was recognized as a result of a change in projected cash payments.
Financial Instruments	Financial Instruments —The Company’s financial instruments include debt and certain acquisition-related liabilities (deferred consideration and noncompete obligations). The carrying value and fair value of these financial instruments as of December 31, 2016 and January 2, 2016 were: December 31, 2016 January 2, 2016 Fair Value Carrying Value Fair Value Carrying Value Level 2 Long-term debt(1) $ $ $ $ Level 3 Current portion of deferred consideration and noncompete obligations(2) Long term portion of deferred consideration and noncompete obligations(3) (1) $6.5 million included in current portion of debt as of December 31, 2016 and January 2, 2016. (2) Included in current portion of acquisition-related liabilities on the consolidated balance sheets. (3) Included in acquisition-related liabilities on the consolidated balance sheets. The fair value of debt was determined based on observable, or Level 2 inputs, such as interest rates, bond yields and quoted prices in inactive markets. The fair values of the deferred consideration and noncompete obligations were determined based on unobservable, or Level 3, inputs, including the cash payment terms in the purchase agreements and a discount rate reflecting the Company’s credit risk. The discount rate used is generally consistent with that used when the obligations were initially recorded. Securities with a maturity of three months or less are considered cash equivalents and the fair value of these assets approximates their carrying value.
New Accounting Standards	New Accounting Standards — In January 2017, the Financial Accounting Standards Board (“FASB”) issued a new Accounting Standards Update (“ASU”) 2017-04 Intangibles - Goodwill and Other (Topic 350) , which simplifies the test for goodwill impairment. The ASU eliminates the two step goodwill impairment test and replaces it with a single step test. The single step test compares the carrying amount of a reporting unit to its fair value; if the carrying amount is greater than the fair value the difference is the amount of the goodwill impairment. Step zero is left unchanged. Therefore, entities that wish do a qualitative assessment are still permitted to do so. The ASU is effective for SEC filers for fiscal years beginning after December 15, 2020. However, the Company will early adopt this ASU as of the beginning of fiscal year 2017. In March 2016, the FASB issued a new accounting standard with targeted amendments to the accounting for employee share-based payments. ASU 2016-09, Improvements to Employee Share-Based Payment Accounting , requires that the income tax effect of share-based awards be recognized in the income statement and allows entities to elect an accounting method to recognize forfeitures as they occur or to estimate forfeitures, as is currently required. The ASU is effective for public entities for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2016. However, the Company early adopted this ASU as of the beginning of fiscal year 2016 and made an election to recognize forfeitures as they occur. The ASU adoption was applied using a modified retrospective method by means of a $1.7 million cumulative-effect adjustment to accumulated earnings as of the beginning of the fiscal year. In February 2016, the FASB issued a new accounting standard related to lease accounting, ASU No. 2016-02, Leases , which will result in lessees recognizing most leases on the balance sheet. Lessees are required to disclose more quantitative and qualitative information about their leases than current U.S. GAAP requires. The ASU is effective for public entities for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2018. As of December 31, 2016 and January 2, 2016, the Company’s undiscounted minimum contractual commitments under long-term operating leases, which were not recorded on the balance sheet, were $31.3 million and $21.9 million, respectively, which is an estimate of the effect to lease obligations and property, plant and equipment that the new accounting standard would have as of the dates noted prior to the effect of discounting. In May 2014, the FASB issued a new accounting standard to improve and converge the financial reporting requirements for revenue from contracts with customers. ASU No. 2014-09, Revenue from Contracts with Customers , prescribes a five-step model for revenue recognition that will replace most existing revenue recognition guidance in U.S. GAAP. The ASU will supersede nearly all existing revenue recognition guidance under U.S. GAAP and provides that an entity recognize revenue when it transfers promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. This update also requires additional disclosure about the nature, amount, timing and uncertainty of revenue and cash flows arising from customer contracts, including significant judgments and changes in judgments, and assets recognized from costs incurred to obtain or fulfill a contract. ASU No. 2014-09 allows for either full retrospective or modified retrospective adoption. In July 2015, the FASB postponed the effective date of the new revenue standard by one year to the first quarter of 2018. Early adoption is permitted, but no earlier than 2017. In 2016, the Company established an implementation team (“team”) and engaged external advisers to develop a multi-phase plan to assess the Company’s business and contracts, as well as any changes to processes or systems to adopt the requirements of the new standard. The team has updated the assessment for new ASU updates and for newly acquired businesses. The team is in the process of developing its conclusions on several aspects of the standard including variable consideration, identification of performance obligations and the determination of when control of goods and services transfers to the Company’s customers.
Reclassifications	Reclassifications —Certain amounts in the prior year have been reclassified to conform to the presentation in the current period.
Summit Materials, LLC
Company Information
Initial Public Offering	Summit Inc.’s Equity Offerings — Summit Inc. commenced operations on March 11, 2015 upon the pricing of the initial public offering of its Class A common stock (“IPO”). Summit Inc. raised $433.0 million, net of underwriting discounts, through the issuance of 25,555,555 shares of Class A common stock at a public offering price of $18.00 per share. Summit Inc. used the offering proceeds to purchase a number of newly-issued Class A Units (“LP Units”) from Summit Holdings equal to the number of shares of Class A common stock issued to the public. Summit Inc. caused Summit Holdings to use these proceeds: (i) to redeem $288.2 million in aggregate principal amount of outstanding 10 1 / 2 % senior notes due January 31, 2020 (“2020 Notes”); (ii) to purchase 71,428,571 Class B Units of Continental Cement Company, L.L.C. (“Continental Cement”); (iii) to pay a one-time termination fee of $13.8 million in connection with the termination of a transaction and management fee agreement with Blackstone Capital Partners V L.P.; and (iv) for general corporate purposes. The $288.2 million redemption of 2020 Notes was completed at a redemption price equal to par plus an applicable premium of $38.2 million plus $5.2 million of accrued and unpaid interest.
Follow-On Offering	On August 11, 2015, Summit Inc. raised $555.8 million, net of underwriting discounts, through the issuance of 22,425,000 shares of Class A common stock at a public offering price of $25.75 per share ("the August 2015 follow-on offering"). Summit Inc. used these proceeds to purchase 3,750,000 newly-issued LP Units from Summit Holdings and 18,675,000 LP Units from certain pre-IPO owners, at a purchase price per LP Unit equal to the public offering price per share of Class A common stock, less underwriting discounts and commissions. Summit Holdings used the proceeds from the 3,750,000 newly-issued LP Units to pay the deferred purchase price of $80.0 million related to the July 17, 2015 acquisition of a cement plant and quarry in Davenport, Iowa, and seven cement terminals along the Mississippi River (the “Davenport Assets”) and for general corporate purposes.
Principles of Consolidation	Principles of Consolidation –The consolidated financial statements include the accounts of Summit LLC and its majority owned subsidiaries. All intercompany balances and transactions have been eliminated. The Company attributes consolidated member’s interest and net income separately to the controlling and noncontrolling interests. Noncontrolling interests in consolidated subsidiaries represent a 20% ownership in Ohio Valley Asphalt, LLC and, prior to the IPO and concurrent purchase of the noncontrolling interests of Continental Cement, a 30% redeemable ownership in Continental Cement. The Company accounts for investments in entities for which it has an ownership of 20% to 50% using the equity method of accounting. The Company’s fiscal year is based on a 52-53 week year with each quarter composed of 13 weeks ending on a Saturday. The 53-week year occurs approximately once every seven years and occurred in 2015. The additional week in the 53-week year was included in the fourth quarter of 2015
Use of Estimates	Use of Estimates — Preparation of these consolidated financial statements in conformity with U.S. generally accepted accounting principles (“U.S. GAAP”) requires management to make estimates and assumptions. These estimates and the underlying assumptions affect the amounts of assets and liabilities reported, disclosures about contingent assets and liabilities and reported amounts of revenue and expenses. Such estimates include the valuation of accounts receivable, inventories, valuation of deferred tax assets, goodwill, intangibles and other long-lived assets, pension and other postretirement obligations and asset retirement obligations. Estimates also include revenue earned on contracts and costs to complete contracts. Most of the Company’s paving and related services are performed under fixed unit-price contracts with state and local governmental entities. Management regularly evaluates its estimates and assumptions based on historical experience and other factors, including the current economic environment. As future events and their effects cannot be determined with precision, actual results can differ significantly from estimates made. Changes in estimates, including those resulting from continuing changes in the economic environment, are reflected in the Company’s consolidated financial statements when the change in estimate occurs.
Business and Credit Concentrations	Business and Credit Concentrations— The Company’s operations are conducted primarily across 21 U.S. states and in British Columbia, Canada, with the most significant revenue generated in Texas, Kansas, Utah, and Missouri. The Company’s accounts receivable consist primarily of amounts due from customers within these areas. Therefore, collection of these accounts is dependent on the economic conditions in the aforementioned states, as well as specific situations affecting individual customers. Credit granted within the Company’s trade areas has been granted to many customers, and management does not believe that a significant concentration of credit exists with respect to any individual customer or group of customers. No single customer accounted for more than 10% of the Company’s total revenue in 2016, 2015 or 2014.
Accounts Receivable	Accounts Receivable —Accounts receivable are stated at the amount management expects to collect from outstanding balances. Management provides for probable uncollectible amounts through a charge to earnings and a credit to a valuation allowance based on its assessment of the collectability of individual accounts. In establishing the allowance, management considers historical losses adjusted to take into account current market conditions and its customers’ financial condition, the amount of receivables in dispute, the current receivables aging and current payment terms. Balances that remain outstanding after reasonable collection efforts are exercised are written off through a charge to the valuation allowance. The balances billed but not paid by customers, pursuant to retainage provisions included in contracts, are generally due upon completion of the contracts.
Revenue and Cost Recognition	Revenue and Cost Recognition —Revenue for product sales are recognized when evidence of an arrangement exists, the fee is fixed or determinable, title passes, which is generally when the product is shipped, and collection is reasonably assured. Product revenue includes sales of aggregates, cement and other materials to customers, net of discounts, allowances or taxes, as applicable. Revenue from construction contracts are included in service revenue and are recognized under the percentage-of-completion accounting method. The percent complete is measured by the cost incurred to date compared to the estimated total cost of each project. This method is used as management considers expended cost to be the best available measure of progress on these contracts, the majority of which are completed within one year, but may occasionally extend beyond one year. Inherent uncertainties in estimating costs make it at least reasonably possible that the estimates used will change within the near term and over the life of the contracts. Contract costs include all direct material and labor costs and those indirect costs related to contract performance and completion. Provisions for estimated losses on uncompleted contracts are made in the period in which such losses are estimable. General and administrative costs are charged to expense as incurred. Changes in job performance, job conditions and estimated profitability, including those arising from contract penalty provisions and final contract settlements, may result in revisions to costs and income. Such revisions are recognized in the period in which they are determined. An amount equal to contract costs incurred that are attributable to claims is included in revenue when realization is probable and the amount can be reliably estimated. Costs and estimated earnings in excess of billings are composed principally of revenue recognized on contracts (on the percentage-of-completion method) for which billings had not been presented to customers because the amount were not billable under the contract terms at the balance sheet date. In accordance with the contract terms, the unbilled receivables at December 31, 2016 will be billed in 2017. Billings in excess of costs and estimated earnings represent billings in excess of revenue recognized. Revenue from the receipt of waste fuels is classified as service revenue and is based on fees charged for the waste disposal, which are recognized when the waste is accepted.
Inventories	Inventories —Inventories consist of stone that has been removed from quarries and processed for future sale, cement, raw materials and finished concrete blocks. Inventories are valued at the lower of cost or market and are accounted for on a first-in first-out basis or an average cost basis. If items become obsolete or otherwise unusable or if quantities exceed what is projected to be sold within a reasonable period of time, they will be charged to costs of production in the period that the items are designated as obsolete or excess inventory. Stripping costs are costs of removing overburden and waste material to access aggregate materials and are recognized in cost of revenue in the same period as the revenue from the sale of the inventory.
Property, Plant and Equipment, net	Property, Plant and Equipment, net —Property, plant and equipment are recorded at cost, less accumulated depreciation, depletion and amortization. Expenditures for additions and improvements that significantly add to the productive capacity or extend the useful life of an asset are capitalized. Repair and maintenance costs that do not substantially expand productive capacity or extend the life of property, plant and equipment are expensed as incurred. Landfill airspace is included in property, plant and equipment at cost and is amortized based on the portion of the airspace used during the period compared to the gross estimated value of available airspace, which is updated periodically as circumstances dictate. Management reassesses the landfill airspace capacity with any changes in value recorded in cost of revenue. Capitalized landfill costs include expenditures for the acquisition of land and related airspace, engineering and permitting costs, cell construction costs and direct site improvement costs. Upon disposal of an asset, the cost and related accumulated depreciation are removed from the Company’s accounts and any gain or loss is included in general and administrative expenses. Depreciation on property, plant and equipment, including assets subject to capital leases, is generally computed on a straight-line basis. Depletion of mineral reserves is computed based on the portion of the reserves used during the period compared to the gross estimated value of proven and probable reserves, which is updated periodically as circumstances dictate. Leasehold improvements are amortized on a straight-line basis over the lesser of the asset’s useful life or the remaining lease term. The estimated useful lives are generally as follows: Buildings and improvements 10 - 30 years Plant, machinery and equipment 15 - 20 years Office equipment 3 - 7 years Truck and auto fleet 5 - 8 years Mobile equipment and barges 6 - 8 years Landfill airspace and improvements 10 - 30 years Other 4 - 20 years The Company reviews the carrying value of property, plant and equipment for impairment whenever events or circumstances indicate that the carrying value of an asset may not be recoverable from the estimated future cash flows expected to result from its use and eventual disposition. Such indicators may include, among others, deterioration in general economic conditions, adverse changes in the markets in which an entity operates, increases in input costs that have a negative effect on earnings and cash flows or a trend of negative or declining cash flows over multiple periods. Property, plant and equipment is tested for impairment at the lowest level for which identifiable cash flows are largely independent of the cash flows of other assets. As a result, the property, plant and equipment impairment test is at a significantly lower level than the level at which goodwill is tested for impairment. In markets where the Company does not produce downstream products, such as ready-mix concrete, asphalt paving mix and paving and related services, the lowest level of largely independent identifiable cash flows is at the individual aggregates operation or a group of aggregates operations collectively serving a local market or the cement operations. Conversely, in vertically-integrated markets, the cash flows of the downstream and upstream businesses are not largely independently identifiable and the vertically-integrated operations are considered the lowest level of largely independent identifiable cash flows. Assets are assessed for impairment charges when identified for disposition. Projected losses from disposition are recognized in the period in which they become estimable, which may be in advance of the actual disposition. The net gain (loss) from asset dispositions recognized in general and administrative expenses in fiscal years 2016, 2015 and 2014 was $6.8 million, $23.5 million and ($2.6 million), respectively. No material impairment charges have been recognized on assets held for use in 2016, 2015 or 2014. The losses are commonly a result of the cash flows expected from selling the asset being less than the expected cash flows that could be generated from holding the asset for use.
Accrued Mining and Landfill Reclamation	Accrued Mining and Landfill Reclamation —The mining reclamation reserve and financial commitments for landfill closure and post-closure activities are based on management’s estimate of future cost requirements to reclaim property at both currently operating and closed sites. Estimates of these obligations have been developed based on management’s interpretation of current requirements and proposed regulatory changes and are intended to approximate fair value. Costs are estimated in current dollars, inflated until the expected time of payment, using an inflation rate of 2.5%, and then discounted back to present value using a credit-adjusted, risk-free rate on obligations of similar maturity, adjusted to reflect the Company’s credit rating. Changes in the credit-adjusted, risk-free rate do not change recorded liabilities. However, subsequent increases in the recognized obligations are measured using a current credit-adjusted, risk-free rate. Decreases in the recognized obligations are measured at the initial credit-adjusted, risk-free rate. Significant changes in inflation rates or the amount or timing of future cost estimates typically result in both (1) a current adjustment to the recorded liability (and corresponding adjustment to the asset) and (2) a change in accretion of the liability and depreciation of the asset to be recorded prospectively over the remaining capacity of the unmined quarry or landfill.
Intangible Assets	Intangible Assets —The Company’s intangible assets are primarily composed of lease agreements and reserve rights. The assets related to lease agreements reflect the submarket royalty rates paid under agreements, primarily, for extracting aggregates. The values were determined as of the respective acquisition dates by a comparison of market-royalty rates to contract-royalty rates. The reserve rights relate to aggregate reserves to which the Company has the rights of ownership, but do not own the reserves. The intangible assets are amortized on a straight-line basis over the lives of the leases. The following table shows intangible assets by type and in total: December 31, 2016 January 2, 2016 Gross Net Gross Net Carrying Accumulated Carrying Carrying Accumulated Carrying Amount Amortization Amount Amount Amortization Amount Leases $ $ $ $ $ $ Reserve rights Trade names Other Total intangible assets $ $ $ $ $ $ Amortization expense in 2016, 2015 and 2014 was $2.6 million, $2.2 million and $0.9 million, respectively. The estimated amortization expense for intangible assets for each of the next five years and thereafter is as follows: 2017 $ 2018 2019 2020 2021 Thereafter Total $
Goodwill	Goodwill —Goodwill represents the purchase price paid in excess of the fair value of net tangible and intangible assets acquired. Goodwill recorded in connection with the Company’s acquisitions is primarily attributable to the expected profitability, assembled workforces of the acquired businesses and the synergies expected to arise after the Company’s acquisition of those businesses. Goodwill is not amortized, but is tested annually for impairment as of the first day of the fourth quarter and at any time that events or circumstances indicate that goodwill may be impaired. A qualitative approach may first be applied to determine whether it is more likely than not that the estimated fair value of a reporting unit is less than its carrying amount. If, as a result of the qualitative assessment, it is determined that an impairment is more likely than not, the two-step quantitative impairment test is then performed, otherwise further analysis is not required. The two-step impairment test first identifies potential goodwill impairment for each reporting unit and then, if necessary, measures the amount of the impairment loss.
Income Taxes	Income Taxes —As a limited liability company, the Company’s federal and state income tax attributes are generally passed to its member. However, certain subsidiaries, or subsidiary groups, of the Company are taxable entities subject to income taxes in the United States and Canada, the provisions for which are included in the consolidated financial statements. Significant judgments and estimates are required in the determination of the consolidated income tax expense. For the Company’s taxable entities, deferred income tax assets and liabilities are computed for differences between the tax basis and financial statement amounts that will result in taxable or deductible amounts in the future based on enacted tax laws and rates applicable to the jurisdictions in which they arise and periods in which the differences are expected to affect taxable income. A valuation allowance is recognized for deferred tax assets if it is more likely than not that some portion or all of the net deferred tax assets will not be realized. In making such a determination, all available positive and negative evidence is considered, including future reversals of existing taxable temporary differences, projected future taxable income, tax-planning strategies, and results of recent operations. If the Company determines it would be able to realize its deferred tax assets for which a valuation allowance had been recorded then an adjustment would be made to the deferred tax asset valuation allowance, which would reduce the provision for income taxes. The Company evaluates the tax positions taken on income tax returns that remain open to examination by the respective tax authorities from prior years and positions expected to be taken on the current year tax returns to identify uncertain tax positions. Unrecognized tax benefits on uncertain tax positions are recorded on the basis of a two-step process in which (1) the Company determines whether it is more likely than not that the tax positions will be sustained on the basis of the technical merits of the position and (2) for those tax positions that meet the more-likely-than-not recognition threshold, the largest amount of tax benefit that is more than 50 percent likely to be realized upon ultimate settlement with the related tax authority is recognized. Interest and penalties related to unrecognized tax benefits are recorded as income tax expense.
Fair Value Measurements	Fair Value Measurements— Certain acquisitions made by the Company require the payment of contingent amounts of purchase consideration. These payments are contingent on specified operating results being achieved in periods subsequent to the acquisition and will only be made if earn-out thresholds are achieved. Contingent consideration obligations are measured at fair value each reporting period. Any adjustments to fair value are recognized in earnings in the period identified. The Company has entered into interest rate derivatives on $200.0 million of its term loan borrowings to add stability to interest expense and to manage its exposure to interest rate movements. The effective portion of changes in the fair value of derivatives designated and that qualify as cash flow hedges is recorded in accumulated other comprehensive income and will be subsequently reclassified into earnings in the period that the hedged forecasted transaction affects earnings. The fair value of contingent consideration and derivatives as of December 31, 2016 and January 2, 2016 was: 2016 2015 Current portion of acquisition-related liabilities and Accrued expenses: Contingent consideration $ $ Cash flow hedges Acquisition-related liabilities and Other noncurrent liabilities Contingent consideration $ $ Cash flow hedges The fair value accounting guidance establishes the following fair value hierarchy that prioritizes the inputs used to measure fair value: Level 1 — Unadjusted quoted prices for identical assets or liabilities in active markets. Level 2 — Inputs other than Level 1 that are based on observable market data, either directly or indirectly. These include quoted prices for similar assets or liabilities in active markets, quoted prices for identical assets or liabilities in inactive markets, inputs that are observable that are not prices and inputs that are derived from or corroborated by observable markets. Level 3 — Valuations developed from unobservable data, reflecting the Company’s own assumptions, which market participants would use in pricing the asset or liability. The fair value of contingent consideration was based on unobservable, or Level 3, inputs, including projected probability-weighted cash payments and an 11.0% discount rate, which reflects a market discount rate. Changes in fair value may occur as a result of a change in actual or projected cash payments, the probability weightings applied by the Company to projected payments or a change in the discount rate. Significant increases or decreases in any of these inputs in isolation could result in a lower, or higher, fair value measurement. The fair value of the cash flow hedges are based on observable, or Level 2, inputs such as interest rates, bond yields and prices in inactive markets. There were no material adjustments to the fair value of contingent consideration in 2015 or to cash flow hedges in 2016 or 2015. In 2016, a $6.1 million increase in the fair value of contingent consideration was recognized as a result of a change in projected cash payments.
Financial Instruments	Financial Instruments —The Company’s financial instruments include debt and certain acquisition-related liabilities (deferred consideration and noncompete obligations). The carrying value and fair value of these financial instruments as of December 31, 2016 and January 2, 2016 were: December 31, 2016 January 2, 2016 Fair Value Carrying Value Fair Value Carrying Value Level 2 Long-term debt (1) $ $ $ $ Level 3 Current portion of deferred consideration and noncompete obligations (2) Long term portion of deferred consideration and noncompete obligations (3) (1) (2) (3) The fair value of debt was determined based on observable, or Level 2 inputs, such as interest rates, bond yields and quoted prices in inactive markets. The fair values of the deferred consideration and noncompete obligations were determined based on unobservable, or Level 3, inputs, including the cash payment terms in the purchase agreements and a discount rate reflecting the Company’s credit risk. The discount rate used is generally consistent with that used when the obligations were initially recorded. Securities with a maturity of three months or less are considered cash equivalents and the fair value of these assets approximates their carrying value.
New Accounting Standards	New Accounting Standards — In January 2017, the Financial Accounting Standards Board (“FASB”) issued a new Accounting Standards Update (“ASU”) 2017-04 Intangibles - Goodwill and Other (Topic 350) , which simplifies the test for goodwill impairment. The ASU eliminates the two step goodwill impairment test and replaces it with a single step test. The single step test compares the carrying amount of a reporting unit to its fair value; if the carrying amount is greater than the fair value the difference is the amount of the goodwill impairment. Step zero is left unchanged. Therefore, entities that wish do a qualitative assessment are still permitted to do so. The ASU is effective for SEC filers for fiscal years beginning after December 15, 2020. However, the Company will early adopt this ASU as of the beginning of fiscal year 2017. In March 2016, the FASB issued a new accounting standard with targeted amendments to the accounting for employee share-based payments. ASU 2016-09, Improvements to Employee Share-Based Payment Accounting , requires that the income tax effect of share-based awards be recognized in the income statement and allows entities to elect an accounting method to recognize forfeitures as they occur or to estimate forfeitures, as is currently required. The ASU is effective for public entities for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2016. However, the Company early adopted this ASU as of the beginning of fiscal year 2016 and made an election to recognize forfeitures as they occur. The ASU adoption was applied using a modified retrospective method by means of a $1.7 million cumulative-effect adjustment to accumulated earnings as of the beginning of the fiscal year. In February 2016, the FASB issued a new accounting standard related to lease accounting, ASU No. 2016-02, Leases , which will result in lessees recognizing most leases on the balance sheet. Lessees are required to disclose more quantitative and qualitative information about their leases than current U.S. GAAP requires. The ASU is effective for public entities for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2018. As of December 31, 2016 and January 2, 2016, the Company’s undiscounted minimum contractual commitments under long-term operating leases, which were not recorded on the balance sheet, were $31.3 million and $21.9 million, respectively, which is an estimate of the effect to lease obligations and property, plant and equipment that the new accounting standard would have as of the dates noted, prior to the effect of discounting. In May 2014, the FASB issued a new accounting standard to improve and converge the financial reporting requirements for revenue from contracts with customers. ASU No. 2014-09, Revenue from Contracts with Customers , prescribes a five-step model for revenue recognition that will replace most existing revenue recognition guidance in U.S. GAAP. The ASU will supersede nearly all existing revenue recognition guidance under U.S. GAAP and provides that an entity recognize revenue when it transfers promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. This update also requires additional disclosure about the nature, amount, timing and uncertainty of revenue and cash flows arising from customer contracts, including significant judgments and changes in judgments, and assets recognized from costs incurred to obtain or fulfill a contract. ASU No. 2014-09 allows for either full retrospective or modified retrospective adoption. In July 2015, the FASB postponed the effective date of the new revenue standard by one year to the first quarter of 2018. Early adoption is permitted, but no earlier than 2017. In 2016, the Company established an implementation team (“team”) and engaged external advisers to develop a multi-phase plan to assess the Company’s business and contracts, as well as any changes to processes or systems to adopt the requirements of the new standard. The team has updated the assessment for new ASU updates and for newly acquired businesses. The team is in the process of developing its conclusions on several aspects of the standard including variable consideration, identification of performance obligations and the determination of when control of goods and services transfers to the Company’s customers.
Reclassifications	Reclassifications —Certain amounts in the prior year have been reclassified to conform to the presentation in the current period.

Summary of Organization and S33

Summary of Organization and Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2016
Company Information
Estimated Useful Lives of Assets	Buildings and improvements 10 - 30 years Plant, machinery and equipment 15 - 20 years Office equipment 3 - 7 years Truck and auto fleet 5 - 8 years Mobile equipment and barges 6 - 8 years Landfill airspace and improvements 10 - 30 years Other 4 - 20 years
Intangible Assets by Type and in Total	December 31, 2016 January 2, 2016 Gross Net Gross Net Carrying Accumulated Carrying Carrying Accumulated Carrying Amount Amortization Amount Amount Amortization Amount Leases $ $ $ $ $ $ Reserve rights Trade names Other Total intangible assets $ $ $ $ $ $
Estimated Amortization Expense for Intangible Assets	2017 $ 2018 2019 2020 2021 Thereafter Total $
Schedule of Contingent Consideration and Derivatives Measured at Fair Value	2016 2015 Current portion of acquisition-related liabilities and Accrued expenses: Contingent consideration $ $ Cash flow hedges Acquisition-related liabilities and Other noncurrent liabilities Contingent consideration $ $ Cash flow hedges
Schedule of Carrying Value and Fair Value of Financial Instruments	December 31, 2016 January 2, 2016 Fair Value Carrying Value Fair Value Carrying Value Level 2 Long-term debt(1) $ $ $ $ Level 3 Current portion of deferred consideration and noncompete obligations(2) Long term portion of deferred consideration and noncompete obligations(3) (1) $6.5 million included in current portion of debt as of December 31, 2016 and January 2, 2016. (2) Included in current portion of acquisition-related liabilities on the consolidated balance sheets. (3) Included in acquisition-related liabilities on the consolidated balance sheets.
Summit Materials, LLC
Company Information
Estimated Useful Lives of Assets	Buildings and improvements 10 - 30 years Plant, machinery and equipment 15 - 20 years Office equipment 3 - 7 years Truck and auto fleet 5 - 8 years Mobile equipment and barges 6 - 8 years Landfill airspace and improvements 10 - 30 years Other 4 - 20 years
Intangible Assets by Type and in Total	December 31, 2016 January 2, 2016 Gross Net Gross Net Carrying Accumulated Carrying Carrying Accumulated Carrying Amount Amortization Amount Amount Amortization Amount Leases $ $ $ $ $ $ Reserve rights Trade names Other Total intangible assets $ $ $ $ $ $
Estimated Amortization Expense for Intangible Assets	2017 $ 2018 2019 2020 2021 Thereafter Total $
Schedule of Contingent Consideration and Derivatives Measured at Fair Value	2016 2015 Current portion of acquisition-related liabilities and Accrued expenses: Contingent consideration $ $ Cash flow hedges Acquisition-related liabilities and Other noncurrent liabilities Contingent consideration $ $ Cash flow hedges
Schedule of Carrying Value and Fair Value of Financial Instruments	December 31, 2016 January 2, 2016 Fair Value Carrying Value Fair Value Carrying Value Level 2 Long-term debt (1) $ $ $ $ Level 3 Current portion of deferred consideration and noncompete obligations (2) Long term portion of deferred consideration and noncompete obligations (3)

Acquisitions (Tables)

Acquisitions (Tables)	12 Months Ended
	Dec. 31, 2016
Summary of Assets Acquired and Liabilities Assumed	Year ended Davenport Year Ended December 31, July 17, January 2, 2016 2016 2015 (excluding Davenport) Financial assets $ $ — $ Inventories Property, plant and equipment Intangible assets — — Other assets Financial liabilities Other long-term liabilities Net assets acquired Goodwill Purchase price Acquisition related liabilities — Bettendorf assets — Other — — Net cash paid for acquisitions $ $ $
Summit Materials, LLC
Summary of Assets Acquired and Liabilities Assumed	Year ended Davenport Year Ended December 31, July 17, January 2, 2016 2016 2015 (excluding Davenport) Financial assets $ $ — $ Inventories Property, plant and equipment Intangible assets — — Other assets Financial liabilities Other long-term liabilities Net assets acquired Goodwill Purchase price Acquisition related liabilities — Bettendorf assets — Other — — Net cash paid for acquisitions $ $ $

Goodwill (Tables)

Goodwill (Tables)	12 Months Ended
	Dec. 31, 2016
Goodwill by Reportable Segment and in Total	West East Cement Total Balance, December 27, 2014 $ $ $ $ Acquisitions Foreign currency translation adjustments — — Balance, January 2, 2016 $ $ $ $ Acquisitions(1) Foreign currency translation adjustments — — Balance, December 31, 2016 $ $ $ $ Accumulated impairment losses as of December 31, 2016 and January 2, 2016 $ $ $ — $ Reflects goodwill from 2016 acquisitions and working capital adjustments from prior year acquisitions in the West and Cement segments, including $5.4 million related to below-market contracts assumed with the Davenport Assets acquisition.
Summit Materials, LLC
Goodwill by Reportable Segment and in Total	West East Cement Total Balance, December 27, 2014 $ $ $ $ Acquisitions Foreign currency translation adjustments — — Balance, January 2, 2016 $ $ $ $ Acquisitions(1) Foreign currency translation adjustments — — Balance, December 31, 2016 $ $ $ $ Accumulated impairment losses as of December 31, 2016 and January 2, 2016 $ $ $ — $ (1) Reflects goodwill from 2016 acquisitions and working capital adjustments from prior year acquisitions in the West and Cement segments, including $5.4 million related to below-market contracts assumed with the Davenport Assets acquisition.

Accounts Receivable, Net (Table

Accounts Receivable, Net (Tables)	12 Months Ended
	Dec. 31, 2016
Summary of Accounts Receivable, Net	2016 2015 Trade accounts receivable $ $ Retention receivables Receivables from related parties Accounts receivable Less: Allowance for doubtful accounts Accounts receivable, net $ $
Summit Materials, LLC
Summary of Accounts Receivable, Net	2016 2015 Trade accounts receivable $ $ Retention receivables Receivables from related parties Accounts receivable Less: Allowance for doubtful accounts Accounts receivable, net $ $

Inventories (Tables)

Inventories (Tables)	12 Months Ended
	Dec. 31, 2016
Components of Inventories	2016 2015 Aggregate stockpiles $ $ Finished goods Work in process Raw materials Total $ $
Summit Materials, LLC
Components of Inventories	2016 2015 Aggregate stockpiles $ $ Finished goods Work in process Raw materials Total $ $

Property, Plant and Equipment38

Property, Plant and Equipment, net (Tables)	12 Months Ended
	Dec. 31, 2016
Components of Property, Plant and Equipment	2016 2015 Land (mineral bearing) and asset retirement costs $ $ Land (non-mineral bearing) Buildings and improvements Plants, machinery and equipment Mobile equipment and barges Truck and auto fleet Landfill airspace and improvements Office equipment Construction in progress Property, plant and equipment Less accumulated depreciation, depletion and amortization Property, plant and equipment, net $ $
Summit Materials, LLC
Components of Property, Plant and Equipment	2016 2015 Land (mineral bearing) and asset retirement costs $ $ Land (non-mineral bearing) Buildings and improvements Plants, machinery and equipment Mobile equipment and barges Truck and auto fleet Landfill airspace and improvements Office equipment Construction in progress Property, plant and equipment Less accumulated depreciation, depletion and amortization Property, plant and equipment, net $ $

Accrued Expenses (Tables)

Accrued Expenses (Tables)	12 Months Ended
	Dec. 31, 2016
Components of Accrued Expenses	2016 2015 Interest $ $ Payroll and benefits Capital lease obligations Insurance Non-income taxes Professional fees Other(1) Total $ $ Consists primarily of subcontractor and working capital settlement accruals and deferred revenue.
Summit Materials, LLC
Components of Accrued Expenses	2016 2015 Interest $ $ Payroll and benefits Capital lease obligations Insurance Non-income taxes Professional fees Other(1) Total $ $ (1) Consists primarily of subcontractor and working capital settlement accruals and deferred revenue.

Debt (Tables)

Debt (Tables)	12 Months Ended
	Dec. 31, 2016
Schedule of Debt	2016 2015 Term Loan, due 2022: $640.3 million and $646.8 million, net of $2.6 million and $3.1 million discount at December 31, 2016 and January 2, 2016, respectively $ $ 8 1 ⁄ 2 % Senior Notes, due 2022 — 6 1 ⁄ 8 % Senior Notes, due 2023: $650 million, net of $1.6 million and $1.8 million discount at December 31, 2016 and January 2, 2016, respectively Total Current portion of long-term debt Long-term debt $ $
Schedule of Contractual Payments of Long-Term Debt	2017 $ 2018 2019 2020 2021 Thereafter Total Less: Original issue net discount Less: Capitalized loan costs Total debt $
Summary of Activity for Deferred Financing Fees	Deferred financing fees Balance—December 27, 2014 $ Loan origination fees Amortization Write off of deferred financing fees Balance—January 2, 2016 $ Loan origination fees Amortization Balance—December 31, 2016 $
Summit Materials, LLC
Schedule of Debt	2016 2015 Term Loan, due 2022: $640.3 million and $646.8 million, net of $2.6 million and $3.1 million discount at December 31, 2016 and January 2, 2016, respectively $ $ 8 1 ⁄ 2 % Senior Notes, due 2022 — 6 1 ⁄ 8 % Senior Notes, due 2023: $650 million, net of $1.6 million and $1.8 million discount at December 31, 2016 and January 2, 2016, respectively Total Current portion of long-term debt Long-term debt $ $
Schedule of Contractual Payments of Long-Term Debt	2017 $ 2018 2019 2020 2021 Thereafter Total Less: Original issue net discount Less: Capitalized loan costs Total debt $
Summary of Activity for Deferred Financing Fees	Deferred financing fees Balance—December 27, 2014 $ Loan origination fees Amortization Write off of deferred financing fees Balance—January 2, 2016 $ Loan origination fees Amortization Balance—December 31, 2016 $

Accumulated Other Comprehensi41

Accumulated Other Comprehensive Income (Loss) (Tables)	12 Months Ended
	Dec. 31, 2016
Schedule of Changes in Each Component of Accumulated Other Comprehensive Income (Loss)	Accumulated Foreign currency other Change in translation Cash flow hedge comprehensive retirement plans adjustments adjustments loss (income) Balance — December 27, 2014 $ — $ — $ — $ — Postretirement liability adjustment — — Foreign currency translation adjustment — — Loss on cash flow hedges — — Balance — January 2, 2016 $ $ $ $ Postretirement liability adjustment — — Foreign currency translation adjustment — — Loss on cash flow hedges — — Balance — December 31, 2016 $ $ $ $
Summit Materials, LLC
Schedule of Changes in Each Component of Accumulated Other Comprehensive Income (Loss)	Accumulated Foreign currency other Change in translation Cash flow hedge comprehensive retirement plans adjustments adjustments loss Balance — December 28, 2013 $ $ — $ — $ Postretirement curtailment adjustment — — Postretirement liability adjustment — — Foreign currency translation adjustment — — Balance — December 27, 2014 $ $ $ — $ Postretirement liability adjustment — — Foreign currency translation adjustment — — Loss on cash flow hedges — — Balance — January 2, 2016 $ $ $ $ Postretirement liability adjustment — — Foreign currency translation adjustment — — Loss on cash flow hedges — — Balance — December 31, 2016 $ $ $ $

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2016
Components of Income Tax Benefit	2016 2015 2014 Provision for income taxes: Current $ $ $ Deferred Income tax benefit $ $ $
Schedule of Income Tax Benefit	The effective tax rate on pre-tax income differs from the U.S. statutory rate of 35% due to the following: 2016 2015 2014 Income tax expense (benefit) at federal statutory tax rate $ $ $ Less: Income tax benefit at federal statutory tax rate for LLC entities State and local income taxes Permanent differences Effective tax rate change Valuation allowance — Impact of LP Unit ownership change — — Other Income tax benefit $ $ $
Components of Net Deferred Income Tax Liability	2016 2015 Deferred tax (liabilities) assets: Net intangible assets $ $ Accelerated depreciation Net operating loss Investment in limited partnership Mining reclamation reserve Working capital (e.g., accrued compensation, prepaid assets) Net deferred tax assets Less valuation allowance Net deferred tax asset (liability) $ $
Summary of Valuation Allowance	2016 2015 Valuation Allowance: Beginning balance $ $ Additional basis from exchanged LP Units Loss carryforwards Release of valuation allowance and other Ending balance $ $
Summit Materials, LLC
Components of Income Tax Benefit	2016 2015 2014 Provision for income taxes: Current $ $ $ Deferred Income tax benefit $ $ $
Schedule of Income Tax Benefit	2016 2015 2014 Income tax expense (benefit) at federal statutory tax rate $ $ $ Less: Income tax benefit at federal statutory tax rate for LLC entities State and local income taxes Permanent differences Effective tax rate change Valuation allowance — Other Income tax benefit $ $ $
Components of Net Deferred Income Tax Liability	2016 2015 Deferred tax (liabilities) assets: Accelerated depreciation $ $ Net operating loss Investment in limited partnership Net intangible assets Mining reclamation reserve Working capital (e.g., accrued compensation, prepaid assets) Net deferred tax liabilities Less valuation allowance Net deferred tax laibility $ $

Employee Benefit Plans (Tables)

Employee Benefit Plans (Tables)	12 Months Ended
	Dec. 31, 2016
Obligations and Funded Status	2016 2015 Pension Healthcare Pension Healthcare benefits & Life Ins. benefits & Life Ins. Change in benefit obligations: Beginning of period $ $ $ $ Service cost Interest cost Actuarial loss (gain) Change in plan provision — Benefits paid End of period Change in fair value of plan assets: Beginning of period $ $ — $ $ — Actual return on plan assets Employer contributions Benefits paid End of period — — Funded status of plans $ $ $ $ Current liabilities $ — $ $ — $ Noncurrent liabilities Liability recognized $ $ $ $ Amounts recognized in accumulated other comprehensive income: Net actuarial loss $ $ $ $ Prior service cost — — Total amount recognized $ $ $ $
Amounts Recognized in Other Comprehensive (Gain) Loss	2016 2015 2014 Pension Healthcare Pension Healthcare Pension Healthcare benefits & Life Ins. benefits & Life Ins. benefits & Life Ins. Amounts recognized in other comprehensive (income) loss: Net actuarial gain (loss) $ $ $ $ $ $ Prior service cost — — — — Amortization of prior year service cost — — — Curtailment benefit — — — — — Amortization of gain Total amount recognized $ $ $ $ $ $ Components of net periodic benefit cost: Service cost $ $ $ $ $ $ Interest cost Amortization of gain Expected return on plan assets — — — Curtailments — — — — — Amortization of prior service credit — — — Net periodic benefit cost $ $ $ $ $ $
Weighted-Average Assumptions Used to Determine Benefit Obligations	2016 2015 Healthcare Healthcare Pension benefits & Life Ins. Pension benefits & Life Ins. Discount rate 3.61% - 3.81% 3.32% - 3.65% 3.74% - 3.97% 3.34% - 3.80% Expected long-term rate of return on plan assets 7.00% N/A 7.30% N/A
Weighted-Average Assumptions Used to Determine Net Periodic Benefit Cost	2016 2015 2014 Healthcare Healthcare Healthcare Pension benefits & Life Ins. Pension benefits & Life Ins. Pension benefits & Life Ins. Discount rate 3.74% - 3.97% 3.34% - 3.80% 3.50% - 3.98% 3.39% - 3.52% 4.21% - 4.46% 4.33% Expected long-term rate of return on plan assets 7.30% N/A 7.30% N/A 7.50% N/A
Effects of One Percentage-Point Change in Assumed Health Care Cost Trend Rates	2016 2015 Increase Decrease Increase Decrease Total service cost and interest cost components $ $ $ $ APBO
Fair Value of Company's Pension Plans' Assets	2016 Quoted prices in active Total fair markets for identical Observable value assets (Level 1) inputs (Level 2) Fixed income securities: Intermediate—government $ $ — $ Intermediate—corporate — Short-term—government — Short-term—corporate — Equity securities: — U.S. Large cap value — U.S. Large cap growth — U.S. Mid cap value — U.S. Mid cap growth — U.S. Small cap value — U.S. Small cap growth — Managed Futures International — Emerging Markets Commodities Broad Basket Cash — Precious metals — Total $ $ $ 2015 Quoted prices in active Total fair markets for identical Observable value assets (Level 1) inputs (Level 2) Fixed income securities: Intermediate—government $ $ — $ Intermediate—corporate — Short-term—government — Short-term—corporate — Equity securities: U.S. Large cap value — U.S. Large cap growth — U.S. Mid cap value — U.S. Mid cap growth — U.S. Small cap value — U.S. Small cap growth — International — Cash — Precious metals — Total $ $ $
Estimated Benefit Payments	Pension Healthcare and Life benefits Insurance Benefits 2017 $ $ 2018 2019 2020 2021 2022 - 2026
Summit Materials, LLC
Obligations and Funded Status	2016 2015 Pension Healthcare Pension Healthcare benefits & Life Ins. benefits & Life Ins. Change in benefit obligations: Beginning of period $ $ $ $ Service cost Interest cost Actuarial loss (gain) Change in plan provision — Benefits paid End of period Change in fair value of plan assets: Beginning of period $ $ — $ $ — Actual return on plan assets Employer contributions Benefits paid End of period — — Funded status of plans $ $ $ $ Current liabilities $ — $ $ — $ Noncurrent liabilities Liability recognized $ $ $ $ Amounts recognized in accumulated other comprehensive income: Net actuarial loss $ $ $ $ Prior service cost — — Total amount recognized $ $ $ $
Amounts Recognized in Other Comprehensive (Gain) Loss	2016 2015 2014 Pension Healthcare Pension Healthcare Pension Healthcare benefits & Life Ins. benefits & Life Ins. benefits & Life Ins. Amounts recognized in other comprehensive (income) loss: Net actuarial gain (loss) $ $ $ $ $ $ Prior service cost — — — — Amortization of prior year service cost — — — Curtailment benefit — — — — — Amortization of gain Total amount recognized $ $ $ $ $ $ Components of net periodic benefit cost: Service cost $ $ $ $ $ $ Interest cost Amortization of gain Expected return on plan assets — — — Curtailments — — — — — Amortization of prior service credit — — — Net periodic benefit cost $ $ $ $ $ $
Weighted-Average Assumptions Used to Determine Benefit Obligations	2016 2015 Healthcare Healthcare Pension benefits & Life Ins. Pension benefits & Life Ins. Discount rate 3.61% - 3.81% 3.32% - 3.65% 3.74% - 3.97% 3.34% - 3.80% Expected long-term rate of return on plan assets 7.00% N/A 7.30% N/A
Weighted-Average Assumptions Used to Determine Net Periodic Benefit Cost	2016 2015 2014 Healthcare Healthcare Healthcare Pension benefits & Life Ins. Pension benefits & Life Ins. Pension benefits & Life Ins. Discount rate 3.74% - 3.97% 3.34% - 3.80% 3.50% - 3.98% 3.39% - 3.52% 4.21% - 4.46% 4.33% Expected long-term rate of return on plan assets 7.30% N/A 7.30% N/A 7.50% N/A
Effects of One Percentage-Point Change in Assumed Health Care Cost Trend Rates	2016 2015 Increase Decrease Increase Decrease Total service cost and interest cost components $ $ $ $ APBO
Fair Value of Company's Pension Plans' Assets	2016 Quoted prices in active Total fair markets for identical Observable value assets (Level 1) inputs (Level 2) Fixed income securities: Intermediate—government $ $ — $ Intermediate—corporate — Short-term—government — Short-term—corporate — Equity securities: — U.S. Large cap value — U.S. Large cap growth — U.S. Mid cap value — U.S. Mid cap growth — U.S. Small cap value — U.S. Small cap growth — Managed Futures International — Emerging Markets Commodities Broad Basket Cash — Precious metals — Total $ $ $ 2015 Quoted prices in active Total fair markets for identical Observable value assets (Level 1) inputs (Level 2) Fixed income securities: Intermediate—government $ $ — $ Intermediate—corporate — Short-term—government — Short-term—corporate — Equity securities: U.S. Large cap value — U.S. Large cap growth — U.S. Mid cap value — U.S. Mid cap growth — U.S. Small cap value — U.S. Small cap growth — International — Cash — Precious metals — Total $ $ $
Estimated Benefit Payments	Pension Healthcare and Life benefits Insurance Benefits 2017 $ $ 2018 2019 2020 2021 2022 - 2026

Accrued Mining and Landfill R44

Accrued Mining and Landfill Reclamation (Tables)	12 Months Ended
	Dec. 31, 2016
Activity for Asset Retirement Obligations	2016 2015 Beginning balance $ $ Acquired obligations Change in cost estimate Settlement of reclamation obligations Additional liabilities incurred — Accretion expense Ending balance $ $
Summit Materials, LLC
Activity for Asset Retirement Obligations	2016 2015 Beginning balance $ $ Acquired obligations Change in cost estimate Settlement of reclamation obligations Additional liabilities incurred — Accretion expense Ending balance $ $

Net Income Per Share (Tables)

Net Income Per Share (Tables)	12 Months Ended
	Dec. 31, 2016
Net Income Per Share
Schedule of Basic Income Per Share	2016 2015 Net income attributable to Summit Inc. $ $ Weighted average shares of Class A shares outstanding Basic earnings per share $ $ Net income attributable to Summit Inc. $ $ Add: Noncontrolling interest impact of LP Unit conversion — Diluted net income attributable to Summit Inc. Weighted average shares of Class A shares outstanding Add: weighted average of LP Units — Add: stock options — Add: warrants Add: restricted stock units Add: performance stock units Weighted average dilutive shares outstanding Diluted earnings per share $ $

Acquisition-Related Liabiliti46

Acquisition-Related Liabilities (Tables)	12 Months Ended
	Dec. 31, 2016
Remaining Payments Due under Noncompete and Deferred Consideration Agreements	2017 2018 2019 2020 2021 Thereafter Total scheduled payments Present value adjustments Total noncompete obligations and deferred consideration $
Summit Materials, LLC
Remaining Payments Due under Noncompete and Deferred Consideration Agreements	2017 2018 2019 2020 2021 Thereafter Total scheduled payments Present value adjustments Total noncompete obligations and deferred consideration $

Supplemental Cash Flow Inform47

Supplemental Cash Flow Information (Tables)	12 Months Ended
	Dec. 31, 2016
Schedule of Supplemental Cash Flow Information	2016 2015 2014 Cash payments: Interest $ $ $ Income taxes Non cash financing activities: Purchase of noncontrolling interest in Continental Cement $ — $ $ — Stock Dividend — Exchange of LP units to shares of Class A — —
Summit Materials, LLC
Schedule of Supplemental Cash Flow Information	2016 2015 2014 Cash payments: Interest $ $ $ Income taxes Non cash financing activities: Purchase of noncontrolling interest in Continental Cement $ — $ $ —

Leasing Arrangements (Tables)

Leasing Arrangements (Tables)	12 Months Ended
	Dec. 31, 2016
Minimum Contractual Commitments for the Subsequent Five Years under Long-Term Operating Leases	Operating Royalty Leases Agreements 2017 $ $ 2018 2019 2020 2021
Summit Materials, LLC
Minimum Contractual Commitments for the Subsequent Five Years under Long-Term Operating Leases	Operating Royalty Leases Agreements 2017 $ $ 2018 2019 2020 2021

Employee Long Term Incentive 49

Employee Long Term Incentive Plan (Tables)	12 Months Ended
	Dec. 31, 2016
Summary of Information for the Equity Awards Granted	Options Restricted Stock Units Performance Stock Units Warrants Weighted Weighted Weighted Weighted average grant- Number of average grant- Number of average grant- Number of average grant- Number of date fair value restricted date fair value performance date fair value performance date fair value options per unit stock units per unit stock units per unit stock units per unit Beginning balance—January 2, 2016 $ $ — $ — $ Granted — — Forfeited — — — — Exercised — — — — — — Vested — — — — — — Balance—December 31, 2016 $ $ $ $
Weighted Average Assumptions Used to Estimate the Fair Value of Grants	Performance Options Stock Units 2016 2015 2014 2016 Risk-free interest rate 1.75% - 1.97% 1.68% - 1.92% 0.50% - 0.68% 0.88% Dividend yield None None None None Volatility 48% 50% 58% 37% Expected term 10 Years 7 - 10 years 3 - 4 Years 3 Years
Summit Materials, LLC
Summary of Information for the Equity Awards Granted	Options Restricted Stock Units Performance Stock Units Warrants Weighted Weighted Weighted Weighted average grant- Number of average grant- Number of average grant- Number of average grant- Number of date fair value restricted date fair value performance date fair value performance date fair value options per unit stock units per unit stock units per unit stock units per unit Beginning balance—January 2, 2016 $ $ — $ — $ Granted — — Forfeited — — — — Exercised — — — — — — Vested — — — — — — Balance—December 31, 2016 $ $ $ $
Weighted Average Assumptions Used to Estimate the Fair Value of Grants	Performance Options Stock Units 2016 2015 2014 2016 Risk-free interest rate 1.75% - 1.97% 1.68% - 1.92% 0.50% - 0.68% 0.88% Dividend yield None None None None Volatility 48% 50% 58% 37% Expected term 10 Years 7 - 10 years 3 - 4 Years 3 Years

Segment Information (Tables)

Segment Information (Tables)	12 Months Ended
	Dec. 31, 2016
Summary of Financial Data for Company's Reportable Business Segments	2016 2015 2014 Revenue*: West $ $ $ East Cement Total revenue $ $ $ * Intercompany sales are immaterial and the presentation above only reflects sales to external customers. 2016 2015 2014 Adjusted EBITDA: West $ $ $ East Cement Corporate and other Total Adjusted EBITDA Interest expense Depreciation, depletion and amortization Accretion IPO/ Legacy equity modification costs — Loss on debt financings — — Tax receivable agreement expense — — Transaction costs Management fees and expenses Non-cash compensation (Gain) loss on disposal and impairment of assets Other Income (loss) from continuing operations before taxes $ $ $ 2016 2015 2014 Purchases of property, plant and equipment West $ $ $ East Cement Total reportable segments Corporate and other Total purchases of property, plant and equipment $ $ $ 2016 2015 2014 Depreciation, depletion, amortization and accretion: West $ $ $ East Cement Total reportable segments Corporate and other Total depreciation, depletion, amortization and accretion $ $ $ 2016 2015 2014 Total assets: West $ $ $ East Cement Total reportable segments Corporate and other Total $ $ $ 2016 2015 2014 Revenue by product*: Aggregates $ $ $ Cement Ready-mix concrete Asphalt Paving and related services Other Total revenue $ $ $ * Revenue from the liquid asphalt terminals is included in asphalt revenue.
Summit Materials, LLC
Summary of Financial Data for Company's Reportable Business Segments	2016 2015 2014 Revenue*: West $ $ $ East Cement Total revenue $ $ $ * Intercompany sales are immaterial and the presentation above only reflects sales to external customers. 2016 2015 2014 Adjusted EBITDA: West $ $ $ East Cement Corporate and other Total Adjusted EBITDA Interest expense Depreciation, depletion and amortization Accretion IPO/ Legacy equity modification costs — Loss on debt financings — — Transaction costs Management fees and expenses Non-cash compensation (Gain) loss on disposal and impairment of assets Other Income (loss) from continuing operations before taxes $ $ $ 2016 2015 2014 Purchases of property, plant and equipment West $ $ $ East Cement Total reportable segments Corporate and other Total purchases of property, plant and equipment $ $ $ 2016 2015 2014 Depreciation, depletion, amortization and accretion: West $ $ $ East Cement Total reportable segments Corporate and other Total depreciation, depletion, amortization and accretion $ $ $ 2016 2015 2014 Total assets: West $ $ $ East Cement Total reportable segments Corporate and other Total $ $ $ 2016 2015 2014 Revenue by product*: Aggregates $ $ $ Cement Ready-mix concrete Asphalt Paving and related services Other Total revenue $ $ $ *

Senior Notes' Guarantor and N51

Senior Notes' Guarantor and Non-Guarantor Financial Information (Tables) - Summit Materials, LLC	12 Months Ended
	Dec. 31, 2016
Condensed Consolidating Balance Sheets	Condensed Consolidating Balance Sheets December 31, 2016 100% Owned Non- Issuers Guarantors Guarantors Eliminations Consolidated Assets Current assets: Cash and cash equivalents $ $ $ $ $ Accounts receivable, net — Intercompany receivables — — Cost and estimated earnings in excess of billings — — Inventories — — Other current assets — Total current assets Property, plant and equipment, net — Goodwill — — Intangible assets, net — — — Other assets Total assets $ $ $ $ $ Liabilities and Member’s Interest Current liabilities: Current portion of debt $ $ — $ — $ — $ Current portion of acquisition-related liabilities — — Accounts payable Accrued expenses Intercompany payables — Billings in excess of costs and estimated earnings — — Total current liabilities Long-term debt — — — Acquisition-related liabilities — — — Other noncurrent liabilities Total liabilities Total member's interest Total liabilities and member’s interest $ $ $ $ $ Condensed Consolidating Balance Sheets January 2, 2016 100% Owned Non- Issuers Guarantors Guarantors Eliminations Consolidated Assets Current assets: Cash and cash equivalents $ $ $ $ $ Accounts receivable, net Intercompany receivables — Cost and estimated earnings in excess of billings — — Inventories — — Other current assets — Total current assets Property, plant and equipment, net — Goodwill — — Intangible assets, net — — Other assets Total assets $ $ $ $ $ Liabilities and Member’s Interest Current liabilities: Current portion of debt $ $ — $ — $ — $ Current portion of acquisition-related liabilities — — Accounts payable Accrued expenses Intercompany payables — Billings in excess of costs and estimated earnings — — Total current liabilities Long-term debt — — — Acquisition-related liabilities — — — Other noncurrent liabilities Total liabilities Total member's interest Total liabilities and member’s interest $ $ $ $ $
Condensed Consolidating Statements of Operations and Comprehensive Loss	Condensed Consolidating Statements of Operations and Comprehensive Loss Year ended December 31, 2016 100% Owned Non- Issuers Guarantors Guarantors Eliminations Consolidated Revenue $ — $ Cost of revenue (excluding items shown separately below) — General and administrative expenses — Depreciation, depletion, amortization and accretion — Operating (loss) income — Other (income) loss, net Interest expense — Income from continuing operations before taxes Income tax (benefit) expense — — Income from continuing operations Income from discontinued operations — — — — — Net income Net income attributable to noncontrolling interest — — — Net income attributable to member of Summit Materials, LLC $ $ $ $ $ Comprehensive income attributable to member of Summit Materials, LLC $ $ $ $ $ Condensed Consolidating Statements of Operations and Comprehensive Loss Year ended January 2, 2016 100% Owned Non- Issuers Guarantors Guarantors Eliminations Consolidated Revenue $ — $ $ $ $ Cost of revenue (excluding items shown separately below) — General and administrative expenses — Depreciation, depletion, amortization and accretion — Operating (loss) income — Other (income) expense, net Interest expense — Income from continuing operations before taxes Income tax (benefit) expense — — Income from operations Income from discontinued operations — — — Net income Net loss attributable to noncontrolling interest — — — Net income attributable to member of Summit Materials, LLC $ $ $ $ $ Comprehensive (loss) income attributable to member of Summit Materials, LLC $ $ $ $ $ Condensed Consolidating Statements of Operations and Comprehensive Loss Year ended December 27, 2014 Non- Wholly- 100% owned Owned Non- Issuers Guarantor Guarantors Guarantors Eliminations Consolidated Revenue $ — $ $ $ $ $ Cost of revenue (excluding items shown separately below) — General and administrative expenses — Depreciation, depletion, amortization and accretion — Operating (loss) income — Other income, net Interest expense (Loss) income from continuing operations before taxes Income tax (benefit) expense — — (Loss) income from operations Income from discontinued operations — — — — Net (loss) income Net income attributable to noncontrolling interest — — — — Net (loss) income attributable to member of Summit Materials, LLC $ $ $ $ $ $ Comprehensive (loss) income attributable to member of Summit Materials, LLC $ $ $ $ $ $
Condensed Consolidating Statements of Cash Flows	Condensed Consolidating Statements of Cash Flows For the year ended December 31, 2016 100% Owned Non- Issuers Guarantors Guarantors Eliminations Consolidated Net cash (used in) provided by operating activities $ $ $ $ — $ Cash flow from investing activities: Acquisitions, net of cash acquired — — Purchase of property, plant and equipment — Proceeds from the sale of property, plant, and equipment — — Other — — — Net cash used for investing activities — Cash flow from financing activities: Proceeds from investment by member — — Capital issuance costs — — — Net proceeds from debt issuance — — — Loans received from and payments made on loans from other Summit Companies — Payments on long-term debt — — Payments on acquisition-related liabilities — — Financing costs — — — Distributions from partnership — — — Other — — — Net cash provided by financing activities Impact of cash on foreign currency — — — Net (decrease) increase in cash Cash — Beginning of period Cash — End of period $ $ $ $ $ Condensed Consolidating Statements of Cash Flows For the year ended January 2, 2016 100% Owned Non- Issuers Guarantors Guarantors Eliminations Consolidated Net cash (used in) provided by operating activities $ $ $ $ $ Cash flow from investing activities: Acquisitions, net of cash acquired — — — Purchase of property, plant and equipment — Proceeds from the sale of property, plant, and equipment — — Other — — — Net cash used for investing activities — Cash flow from financing activities: Proceeds from investment by member — — Capital issuance costs — — — Net proceeds from debt issuance — — — Loans received from and payments made on loans from other Summit Companies — Payments on long-term debt — Payments on acquisition-related liabilities — — Financing costs — — — Distributions from partnership — — — Other — — — Net cash provided by (used for) financing activities Impact of cash on foreign currency — — — Net increase (decrease) in cash Cash — Beginning of period Cash — End of period $ $ $ $ $ Condensed Consolidating Statements of Cash Flows For the year ended December 27, 2014 Non- Wholly- 100% owned Owned Non- Issuers Guarantor Guarantors Guarantors Eliminations Consolidated Net cash (used in) provided by operating activities $ $ $ $ $ $ Cash flow from investing activities: Acquisitions, net of cash acquired — — — Purchase of property, plant and equipment — Proceeds from the sale of property, plant, and equipment — — — Other — — Net cash used for investing activities Cash flow from financing activities: Proceeds from investment by member — — Net proceeds from debt issuance — — — — Loans received from and payments made on loans from other Summit Companies — Payments on long-term debt — — Payments on acquisition-related liabilities — — — Financing costs — — — — Other — — Net cash provided by (used for) financing activities Impact of cash on foreign currency — — — — Net increase (decrease) in cash Cash — Beginning of period Cash — End of period $ $ $ $ $ $

Supplementary Data (Unaudited)

Supplementary Data (Unaudited) (Tables)	12 Months Ended
	Dec. 31, 2016
Supplemental Financial Information	2016 2015 4Q 3Q 2Q 1Q 4Q 3Q 2Q 1Q Net revenue $ $ $ $ $ $ $ $ Operating income (loss) Income (loss) from continuing operations Net income (loss) Net income (loss) attributable to Summit Inc. Basic earnings per share attributable to Summit Inc. Diluted earnings per share attributable to Summit Inc.
Summit Materials, LLC
Supplemental Financial Information	2016 2015 4Q 3Q 2Q 1Q 4Q 3Q 2Q 1Q Net revenue $ $ $ $ $ $ $ $ Operating income (loss) Income (loss) from continuing operations Net income (loss)

Summary of Organization and S53

Summary of Organization and Significant Accounting Policies - General Information and Equity Offerings (Details) $ / shares in Units, $ in Thousands

Aug. 13, 2015USD ($)facility

Aug. 11, 2015USD ($)$ / sharesshares

Jul. 19, 2015shares

Jul. 17, 2015USD ($)

Mar. 17, 2015USD ($)shares

Mar. 11, 2015USD ($)$ / sharesshares

Apr. 25, 2015USD ($)

Dec. 31, 2016segmentfacilityshares

Jan. 02, 2016USD ($)shares

Nov. 28, 2015USD ($)

Aug. 22, 2015USD ($)

Jul. 08, 2015USD ($)

Apr. 30, 2015USD ($)

Summary Of Significant Accounting Policies And Recent Accounting Pronouncements

Number of plants | facility

2

Number of operating segments | segment

3

Length of fiscal quarter

91 days

Interval period for 53 week fiscal year

7 years

Equity Offering

Proceeds from sale of common stock, net of underwriting discounts

$ 1,037,444

Number of Summit LP units purchased by Company, newly issued units (in shares) | shares

45,124,528

18,675,000

Minimum

Summary Of Significant Accounting Policies And Recent Accounting Pronouncements

Length of fiscal year

364 days

Maximum

Summary Of Significant Accounting Policies And Recent Accounting Pronouncements

Length of fiscal year

371 days

Continental Cement

Principles of Consolidation

Noncontrolling interest elimination (as a percent)

30.00%

Ohio Valley Asphalt

Principles of Consolidation

Noncontrolling interest elimination (as a percent)

20.00%

Davenport Assets

Equity Offering

Cash paid for acquisitions

$ 450,000

$ 370,000

$ 370,000

Summit Materials, LLC

Summary Of Significant Accounting Policies And Recent Accounting Pronouncements

Number of operating segments | segment

3

Summit Materials, LLC | Continental Cement

Principles of Consolidation

Noncontrolling interest elimination (as a percent)

30.00%

Summit Materials, LLC | Ohio Valley Asphalt

Principles of Consolidation

Noncontrolling interest elimination (as a percent)

20.00%

Summit Materials, LLC | Davenport Assets

Equity Offering

Cash paid for acquisitions

$ 450,000

$ 370,000

Summit Holdings LP

Principles of Consolidation

Voting power (as a percent)

100.00%

Noncontrolling interest elimination (as a percent)

5.10%

50.30%

Blackstone Management Partners L.L.C.

Equity Offering

Number of Summit LP units purchased by Company, newly issued units (in shares) | shares

45,124,528

10 1/2% Senior Notes, due 2020

Equity Offering

Senior notes, aggregate principal amount redeemed

$ 288,200

$ 153,800

$ 183,000

$ 336,800

IPO

Equity Offering

Proceeds from sale of common stock, net of underwriting discounts

$ 433,000

IPO | Continental Cement

Equity Offering

Class B units purchased (in shares) | shares

71,428,571

IPO | Affiliates of the Sponsors Blackstone Management Partners and Silverhawk Summit | Termination fee paid to related parties

Equity Offering

Related party expense

$ 13,800

IPO | Common Class A

Equity Offering

Common stock issued (in shares) | shares

25,555,555

Offering price (in dollars per share) | $ / shares

$ 18

IPO | Common Class B

Equity Offering

Common stock issued (in shares) | shares

69,007,297

IPO | Common Class B | Summit Holdings LP

Equity Offering

Class B share cancellation (in shares) | shares

40,345,771

Number of shares of Class B common stock transferred to holders of LP units | shares

28,661,526

IPO | 10 1/2% Senior Notes, due 2020

Equity Offering

Senior notes, aggregate principal amount redeemed

$ 288,200

Senior notes, interest rate (as a percent)

10.50%

Debt Instrument, redemption premium

38,200

Accrued and unpaid interest

$ 5,200

Follow on Public Offering | Davenport Assets

Summary Of Significant Accounting Policies And Recent Accounting Pronouncements

Number of plants | facility

7

Equity Offering

Cash paid for acquisitions

$ 80,000

Follow on Public Offering | Summit Materials, LLC | Davenport Assets

Equity Offering

Cash paid for acquisitions

$ 80,000

Follow on Public Offering | Summit Holdings LP

Equity Offering

Number of Summit LP units purchased by Company, newly issued units (in shares) | shares

3,750,000

Number of Summit LP units purchased by Company, from previous holders (in shares) | shares

18,675,000

Follow on Public Offering | Common Class A

Equity Offering

Proceeds from sale of common stock, net of underwriting discounts

$ 555,800

Common stock issued (in shares) | shares

22,425,000

Offering price (in dollars per share) | $ / shares

$ 25.75

Summary of Organization and S54

Summary of Organization and Significant Accounting Policies - Business and Credit Concentration (Details)	12 Months Ended
	Dec. 31, 2016stateitem	Jan. 02, 2016item	Dec. 27, 2014item
Sales | Customer Concentration Risk
Business and Credit Concentrations
Number of customers accounted for more than 10% of total revenue	0	0	0
Sales | Maximum | Customer Concentration Risk
Business and Credit Concentrations
Customer accounted revenue (as a percent)	10.00%	10.00%	10.00%
Summit Materials, LLC
Business and Credit Concentrations
Number of states in which the entity operates | state	21
Summit Materials, LLC | Sales | Customer Concentration Risk
Business and Credit Concentrations
Number of customers accounted for more than 10% of total revenue	0	0	0
Summit Materials, LLC | Sales | Maximum
Business and Credit Concentrations
Customer accounted revenue (as a percent)	10.00%	10.00%	10.00%

Summary of Organization and S55

Summary of Organization and Significant Accounting Policies - Estimated Useful Lives of Assets (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Jan. 02, 2016	Dec. 27, 2014
Property, Plant and Equipment [Line Items]
Gain (loss) on disposition	$ 6.8	$ 23.5	$ (2.6)
Accrued Mining and Land Reclamation
Inflation Rate Percentage	2.50%
Summit Materials, LLC
Property, Plant and Equipment [Line Items]
Gain (loss) on disposition	$ 6.8	$ 23.5	$ (2.6)
Accrued Mining and Land Reclamation
Inflation Rate Percentage	2.50%
Minimum | Buildings and improvements
Property, Plant and Equipment [Line Items]
Estimated useful life	10 years
Minimum | Buildings and improvements | Summit Materials, LLC
Property, Plant and Equipment [Line Items]
Estimated useful life	10 years
Minimum | Plants, machinery and equipment
Property, Plant and Equipment [Line Items]
Estimated useful life	15 years
Minimum | Plants, machinery and equipment | Summit Materials, LLC
Property, Plant and Equipment [Line Items]
Estimated useful life	15 years
Minimum | Mobile equipment and barges
Property, Plant and Equipment [Line Items]
Estimated useful life	6 years
Minimum | Mobile equipment and barges | Summit Materials, LLC
Property, Plant and Equipment [Line Items]
Estimated useful life	6 years
Minimum | Office equipment
Property, Plant and Equipment [Line Items]
Estimated useful life	3 years
Minimum | Office equipment | Summit Materials, LLC
Property, Plant and Equipment [Line Items]
Estimated useful life	3 years
Minimum | Truck and auto fleet
Property, Plant and Equipment [Line Items]
Estimated useful life	5 years
Minimum | Truck and auto fleet | Summit Materials, LLC
Property, Plant and Equipment [Line Items]
Estimated useful life	5 years
Minimum | Landfill airspace and improvements
Property, Plant and Equipment [Line Items]
Estimated useful life	10 years
Minimum | Landfill airspace and improvements | Summit Materials, LLC
Property, Plant and Equipment [Line Items]
Estimated useful life	10 years
Minimum | Other
Property, Plant and Equipment [Line Items]
Estimated useful life	4 years
Minimum | Other | Summit Materials, LLC
Property, Plant and Equipment [Line Items]
Estimated useful life	4 years
Maximum | Buildings and improvements
Property, Plant and Equipment [Line Items]
Estimated useful life	30 years
Maximum | Buildings and improvements | Summit Materials, LLC
Property, Plant and Equipment [Line Items]
Estimated useful life	30 years
Maximum | Plants, machinery and equipment
Property, Plant and Equipment [Line Items]
Estimated useful life	20 years
Maximum | Plants, machinery and equipment | Summit Materials, LLC
Property, Plant and Equipment [Line Items]
Estimated useful life	20 years
Maximum | Mobile equipment and barges
Property, Plant and Equipment [Line Items]
Estimated useful life	8 years
Maximum | Mobile equipment and barges | Summit Materials, LLC
Property, Plant and Equipment [Line Items]
Estimated useful life	8 years
Maximum | Office equipment
Property, Plant and Equipment [Line Items]
Estimated useful life	7 years
Maximum | Office equipment | Summit Materials, LLC
Property, Plant and Equipment [Line Items]
Estimated useful life	7 years
Maximum | Truck and auto fleet
Property, Plant and Equipment [Line Items]
Estimated useful life	8 years
Maximum | Truck and auto fleet | Summit Materials, LLC
Property, Plant and Equipment [Line Items]
Estimated useful life	8 years
Maximum | Landfill airspace and improvements
Property, Plant and Equipment [Line Items]
Estimated useful life	30 years
Maximum | Landfill airspace and improvements | Summit Materials, LLC
Property, Plant and Equipment [Line Items]
Estimated useful life	30 years
Maximum | Other
Property, Plant and Equipment [Line Items]
Estimated useful life	20 years
Maximum | Other | Summit Materials, LLC
Property, Plant and Equipment [Line Items]
Estimated useful life	20 years

Summary of Organization and S56

Summary of Organization and Significant Accounting policies - Intangible Assets by Type and in Total (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Jan. 02, 2016	Dec. 27, 2014
Finite-Lived Intangible Assets
Gross Carrying Amount	$ 25,843	$ 20,242
Accumulated Amortization	(7,854)	(5,237)
Net Carrying Amount	17,989	15,005
Amortization expense	2,600	2,200	$ 900
Summit Materials, LLC
Finite-Lived Intangible Assets
Gross Carrying Amount	25,843	20,242
Accumulated Amortization	(7,854)	(5,237)
Net Carrying Amount	17,989	15,005
Amortization expense	2,600	2,200	$ 900
Leases
Finite-Lived Intangible Assets
Gross Carrying Amount	15,888	10,357
Accumulated Amortization	(3,382)	(2,531)
Net Carrying Amount	12,506	7,826
Leases | Summit Materials, LLC
Finite-Lived Intangible Assets
Gross Carrying Amount	15,888	10,357
Accumulated Amortization	(3,382)	(2,531)
Net Carrying Amount	12,506	7,826
Reserve Rights
Finite-Lived Intangible Assets
Gross Carrying Amount	8,706	8,636
Accumulated Amortization	(3,710)	(2,078)
Net Carrying Amount	4,996	6,558
Reserve Rights | Summit Materials, LLC
Finite-Lived Intangible Assets
Gross Carrying Amount	8,706	8,636
Accumulated Amortization	(3,710)	(2,078)
Net Carrying Amount	4,996	6,558
Trade Names
Finite-Lived Intangible Assets
Gross Carrying Amount	1,000	1,000
Accumulated Amortization	(658)	(558)
Net Carrying Amount	342	442
Trade Names | Summit Materials, LLC
Finite-Lived Intangible Assets
Gross Carrying Amount	1,000	1,000
Accumulated Amortization	(658)	(558)
Net Carrying Amount	342	442
Other
Finite-Lived Intangible Assets
Gross Carrying Amount	249	249
Accumulated Amortization	(104)	(70)
Net Carrying Amount	145	179
Other | Summit Materials, LLC
Finite-Lived Intangible Assets
Gross Carrying Amount	249	249
Accumulated Amortization	(104)	(70)
Net Carrying Amount	$ 145	$ 179

Summary of Organization and S57

Summary of Organization and Significant Accounting Policies - Estimated Amortization Expense for Intangible Assets (Detail) - USD ($)	Dec. 31, 2016	Jan. 02, 2016
Finite-Lived Intangible Assets
2,017	$ 1,222,000
2,018	1,217,000
2,019	1,198,000
2,020	1,114,000
2,021	1,073,000
Thereafter	12,165,000
Total	17,989,000	$ 15,005,000
Summit Materials, LLC
Finite-Lived Intangible Assets
2,017	1,222,000
2,018	1,217,000
2,019	1,198,000
2,020	1,114,000
2,021	1,073,000
Thereafter	12,165,000
Total	$ 17,989,000	$ 15,005,000

Summary of Organization and S58

Summary of Organization and Significant Accounting Policies - Fair Value Measurements (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Jan. 02, 2016
Fair Value Measurements
Adjustment to contingent consideration	$ 6,100
Level 3
Fair Value Measurements
Current portion of acquisition-related liabilities and Accrued expenses - Contingent consideration	9,288	$ 4,918
Acquisition-related liabilities and Other noncurrent liabilities - Contingent consideration	$ 2,377	2,475
Discount rate	11.00%
Cash flow hedges | Interest rate derivatives | Level 2
Fair Value Measurements
Current portion of acquisition-related liabilities and Accrued expenses - Cash flow hedge	$ 942	224
Acquisition-related liabilities and Other noncurrent liabilities - Cash flow hedge	1,438	681
Cash flow hedges | Interest rate derivatives | Term Loan, due 2022
Fair Value Measurements
Term loan borrowings hedged by derivatives	200,000	200,000
Summit Materials, LLC
Fair Value Measurements
Adjustment to contingent consideration	6,100
Summit Materials, LLC | Level 3
Fair Value Measurements
Current portion of acquisition-related liabilities and Accrued expenses - Contingent consideration	9,288	4,918
Acquisition-related liabilities and Other noncurrent liabilities - Contingent consideration	$ 2,377	2,475
Discount rate	11.00%
Summit Materials, LLC | Cash flow hedges | Interest rate derivatives | Level 2
Fair Value Measurements
Current portion of acquisition-related liabilities and Accrued expenses - Cash flow hedge	$ 942	224
Acquisition-related liabilities and Other noncurrent liabilities - Cash flow hedge	1,438	681
Summit Materials, LLC | Cash flow hedges | Interest rate derivatives | Term Loan, due 2022
Fair Value Measurements
Term loan borrowings hedged by derivatives	$ 200,000	$ 200,000

Summary of Organization and S59

Summary of Organization and Significant Accounting Policies - Carrying Value and Fair Value of Financial Instruments (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Jan. 02, 2016
Financial Instruments
Current portion of debt	$ 6,500	$ 6,500
Summit Materials, LLC
Financial Instruments
Current portion of debt	6,500	6,500
Level 2
Financial Instruments
Current portion of debt	6,500	6,500
Level 2 | Fair Value
Financial Instruments
Long-term debt	1,586,102	1,283,799
Level 2 | Carrying Value
Financial Instruments
Long-term debt	1,536,065	1,291,858
Level 2 | Summit Materials, LLC | Fair Value
Financial Instruments
Long-term debt	1,586,102	1,283,799
Level 2 | Summit Materials, LLC | Carrying Value
Financial Instruments
Long-term debt	1,536,065	1,291,858
Level 3 | Fair Value
Financial Instruments
Current portion of deferred consideration and noncompete obligations	14,874	15,666
Long term portion of deferred consideration and noncompete obligations	30,287	37,502
Level 3 | Carrying Value
Financial Instruments
Current portion of deferred consideration and noncompete obligations	14,874	15,666
Long term portion of deferred consideration and noncompete obligations	30,287	37,502
Level 3 | Summit Materials, LLC | Fair Value
Financial Instruments
Current portion of deferred consideration and noncompete obligations	12,375	13,166
Long term portion of deferred consideration and noncompete obligations	22,784	28,553
Level 3 | Summit Materials, LLC | Carrying Value
Financial Instruments
Current portion of deferred consideration and noncompete obligations	12,375	13,166
Long term portion of deferred consideration and noncompete obligations	$ 22,784	$ 28,553

Summary of Organization and S60

Summary of Organization and Significant Accounting Policies - New Accounting Standards (Details) - USD ($) $ in Millions	Dec. 31, 2016	Jan. 03, 2016	Jan. 02, 2016
Accounting Standards Update 2016-09 | Adjustments for New Accounting Principle, Early Adoption
New Accounting Standards
Cumulative effect adjustment		$ 1.7
Accounting Standards Update 2016-02 | Minimum
New Accounting Standards
Contractual Obligation	$ 31.3		$ 21.9
Summit Materials, LLC | Accounting Standards Update 2016-09 | Adjustments for New Accounting Principle, Early Adoption
New Accounting Standards
Cumulative effect adjustment		$ 1.7
Summit Materials, LLC | Accounting Standards Update 2016-02 | Minimum
New Accounting Standards
Contractual Obligation	$ 31.3		$ 21.9

Acquisitions - Completed Acquis

Acquisitions - Completed Acquisitions Information (Detail) $ in Millions	Oct. 03, 2016facility	Aug. 21, 2016facilityitem	Aug. 19, 2016facility	May 20, 2016item	Apr. 29, 2016USD ($)facilityitem	Mar. 18, 2016facilityitem	Feb. 05, 2016item	Aug. 21, 2015facilityitem	Dec. 31, 2016USD ($)	Mar. 08, 2016USD ($)
8 1/2% Senior Notes, due 2022
Business Acquisition [Line Items]
Debt Instrument, Face Amount | $										$ 250
Debt Instrument, Interest Rate, Stated Percentage									8.50%	8.50%
Summit Materials, LLC | 8 1/2% Senior Notes, due 2022
Business Acquisition [Line Items]
Debt Instrument, Face Amount | $										$ 250
Debt Instrument, Interest Rate, Stated Percentage										8.50%
Midland Concrete | West | Ready-mixed concrete | Cement plant
Business Acquisition [Line Items]
Number of plants acquired	1
Midland Concrete | Summit Materials, LLC | West | Ready-mixed concrete | Cement plant
Business Acquisition [Line Items]
Number of plants acquired	1
Rustin | West | Ready-mixed concrete | Cement plant
Business Acquisition [Line Items]
Number of plants acquired			12
Rustin | Summit Materials, LLC | West | Ready-mixed concrete | Cement plant
Business Acquisition [Line Items]
Number of plants acquired			12
Sierra Ready Mix, LLC
Business Acquisition [Line Items]
Contingent consideration | $					$ 11.1
Contingent consideration, portion related to lease and earnings target | $					$ 10
Paymet of contingent consideration | $									$ 10
Sierra Ready Mix, LLC | West | Aggregates
Business Acquisition [Line Items]
Number of sand and gravel pits acquired | item					1
Sierra Ready Mix, LLC | West | Ready-mixed concrete | Cement plant
Business Acquisition [Line Items]
Number of plants acquired					2
Sierra Ready Mix, LLC | Summit Materials, LLC
Business Acquisition [Line Items]
Contingent consideration | $					$ 11.1
Contingent consideration, portion related to lease and earnings target | $					$ 10
Paymet of contingent consideration | $									$ 10
Sierra Ready Mix, LLC | Summit Materials, LLC | West | Aggregates
Business Acquisition [Line Items]
Number of sand and gravel pits acquired | item					1
Sierra Ready Mix, LLC | Summit Materials, LLC | West | Ready-mixed concrete | Cement plant
Business Acquisition [Line Items]
Number of plants acquired					2
LeGrand Johnson Construction Co. | West | Aggregates
Business Acquisition [Line Items]
Number of sand and gravel pits acquired | item		5
LeGrand Johnson Construction Co. | West | Ready-mixed concrete
Business Acquisition [Line Items]
Number of plants acquired		4
LeGrand Johnson Construction Co. | West | Asphalt
Business Acquisition [Line Items]
Number of plants acquired		3
LeGrand Johnson Construction Co. | Summit Materials, LLC | West | Aggregates
Business Acquisition [Line Items]
Number of sand and gravel pits acquired | item								5
LeGrand Johnson Construction Co. | Summit Materials, LLC | West | Ready-mixed concrete
Business Acquisition [Line Items]
Number of plants acquired								4
LeGrand Johnson Construction Co. | Summit Materials, LLC | West | Asphalt
Business Acquisition [Line Items]
Number of plants acquired								3
APAC Kansas Inc | East | Aggregates
Business Acquisition [Line Items]
Number of sand and gravel pits acquired | item				7
APAC Kansas Inc | Summit Materials, LLC | East | Aggregates
Business Acquisition [Line Items]
Number of sand and gravel pits acquired | item				7
Boxley | East | Aggregates
Business Acquisition [Line Items]
Number of quarries | item						6
Boxley | East | Ready-mixed concrete | Cement plant
Business Acquisition [Line Items]
Number of plants acquired						4
Boxley | East | Asphalt
Business Acquisition [Line Items]
Number of plants acquired						4
Boxley | Summit Materials, LLC | East | Aggregates
Business Acquisition [Line Items]
Number of quarries | item						6
Boxley | Summit Materials, LLC | East | Ready-mixed concrete | Cement plant
Business Acquisition [Line Items]
Number of plants acquired						4
Boxley | Summit Materials, LLC | East | Asphalt
Business Acquisition [Line Items]
Number of plants acquired						4
AMC | East | Aggregates
Business Acquisition [Line Items]
Number of sand and gravel pits acquired | item							5

Acquisitions - Summary of Asset

Acquisitions - Summary of Assets Acquired and Liabilities Assumed (Detail) $ in Thousands	Aug. 30, 2016facility	Aug. 13, 2015USD ($)facility	Jul. 17, 2015USD ($)	Jul. 15, 2015USD ($)	Dec. 31, 2016USD ($)facilityMT	Jan. 02, 2016USD ($)	Dec. 27, 2014USD ($)
Business Acquisition [Line Items]
Net gain on asset disposals					$ 3,102	$ 23,087	$ (6,500)
Number of Plants Owned and Operated | facility					2
Goodwill					$ 782,212	596,397	419,270
Cement
Business Acquisition [Line Items]
Goodwill					204,538	194,163	24,096
Cement | Bettendorf Iowa
Business Acquisition [Line Items]
Net gain on asset disposals			$ 16,600
Summit Materials, LLC
Business Acquisition [Line Items]
Net gain on asset disposals					3,102	23,087	(6,500)
Goodwill					782,212	596,397	419,270
Summit Materials, LLC | Cement
Business Acquisition [Line Items]
Goodwill					$ 204,538	194,163	$ 24,096
Summit Materials, LLC | Cement | Bettendorf Iowa
Business Acquisition [Line Items]
Net gain on asset disposals			16,600
Davenport Assets
Business Acquisition [Line Items]
Cash paid for acquisitions		$ 450,000	370,000			370,000
Inventories				$ 21,776
Property, plant and equipment				275,436
Other assets				6,450
Financial liabilities				(2,190)
Other long-term liabilities				(4,086)
Net assets acquired				297,386
Goodwill				170,067
Purchase price				467,453
Bettendorf assets				(18,743)
Net cash paid for acquisitions				$ 448,710
Davenport Assets | Cement plant
Business Acquisition [Line Items]
Cement production capacity | MT					2
Davenport Assets | Follow on Public Offering
Business Acquisition [Line Items]
Cash paid for acquisitions		$ 80,000
Number of Plants Owned and Operated | facility		7
Davenport Assets | Cement
Business Acquisition [Line Items]
Cash paid for acquisitions		$ 450,000
Davenport Assets | Cement | Cement terminal
Business Acquisition [Line Items]
Number of Plants Owned and Operated | facility					8
Davenport Assets | Summit Materials, LLC
Business Acquisition [Line Items]
Cash paid for acquisitions		450,000	370,000
Inventories			21,776
Property, plant and equipment			275,436
Other assets			6,450
Financial liabilities			(2,190)
Other long-term liabilities			(4,086)
Net assets acquired			297,386
Goodwill			170,067
Purchase price			467,453
Bettendorf assets			(18,743)
Net cash paid for acquisitions			$ 448,710
Davenport Assets | Summit Materials, LLC | Follow on Public Offering
Business Acquisition [Line Items]
Cash paid for acquisitions		80,000
Davenport Assets | Summit Materials, LLC | Cement
Business Acquisition [Line Items]
Cash paid for acquisitions		450,000
Davenport Assets | Summit Materials, LLC | Cement | Cement plant
Business Acquisition [Line Items]
Cement production capacity | MT					2
Davenport Assets | Summit Materials, LLC | Cement | Cement terminal
Business Acquisition [Line Items]
Number of Plants Owned and Operated | facility					8
Davenport Assets | Summit Materials, LLC | Cement | Follow on Public Offering
Business Acquisition [Line Items]
Cash paid for acquisitions		$ 80,000
Number of Plants Owned and Operated | facility		7
Acquisitions (excluding Davenport)
Business Acquisition [Line Items]
Financial assets						12,555
Inventories						2,036
Property, plant and equipment						57,817
Other assets						(745)
Financial liabilities						(13,733)
Other long-term liabilities						(11,289)
Net assets acquired						46,641
Goodwill						15,710
Purchase price						62,351
Acquisition related liabilities						(1,044)
Net cash paid for acquisitions						61,307
Acquisitions (excluding Davenport) | Summit Materials, LLC
Business Acquisition [Line Items]
Financial assets						12,555
Inventories						2,036
Property, plant and equipment						57,817
Other assets						(745)
Financial liabilities						(13,733)
Other long-term liabilities						(11,289)
Net assets acquired						46,641
Goodwill						15,710
Purchase price						62,351
Acquisition related liabilities						(1,044)
Net cash paid for acquisitions						$ 61,307
2016 Acquisitions
Business Acquisition [Line Items]
Financial assets					$ 21,008
Inventories					17,215
Property, plant and equipment					180,321
Intangible assets					5,531
Other assets					6,757
Financial liabilities					(19,052)
Other long-term liabilities					(36,074)
Net assets acquired					175,706
Goodwill					176,319
Purchase price					352,025
Acquisition related liabilities					(11,113)
Bettendorf assets					(5,921)
Other					1,967
Net cash paid for acquisitions					336,958
2016 Acquisitions | Summit Materials, LLC
Business Acquisition [Line Items]
Financial assets					21,008
Inventories					17,215
Property, plant and equipment					180,321
Intangible assets					5,531
Other assets					6,757
Financial liabilities					(19,052)
Other long-term liabilities					(36,074)
Net assets acquired					175,706
Goodwill					176,319
Purchase price					352,025
Acquisition related liabilities					(11,113)
Bettendorf assets					(5,921)
Other					1,967
Net cash paid for acquisitions					$ 336,958
Angelle Assets | Cement | Cement terminal
Business Acquisition [Line Items]
Number of plants acquired | facility	2
Angelle Assets | Summit Materials, LLC | Cement | Cement terminal
Business Acquisition [Line Items]
Number of plants acquired | facility	2

Goodwill - Additional Informati

Goodwill - Additional Information (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2016USD ($)item
Goodwill
Number of reporting units with goodwill | item	12
Accumulated impairment losses | $	$ (68,202)
Summit Materials, LLC
Goodwill
Number of reporting units with goodwill | item	12
Number of reporting units assessed under qualitative assessment | item	7
Goodwill impairment | $	$ 0
Accumulated impairment losses | $	$ (68,202)

Goodwill - Summary by Reportabl

Goodwill - Summary by Reportable Segments(Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Jan. 02, 2016
Goodwill [Roll Forward]
Beginning balance	$ 596,397	$ 419,270
Acquisitions	184,490	185,777
Foreign currency translation adjustments	1,325	(8,650)
Ending balance	782,212	596,397
Accumulated impairment losses	(68,202)
Summit Materials, LLC
Goodwill [Roll Forward]
Beginning balance	596,397	419,270
Acquisitions	184,490	185,777
Foreign currency translation adjustments	1,325	(8,650)
Ending balance	782,212	596,397
Accumulated impairment losses	(68,202)
Summit Materials, LLC | Davenport Assets
Goodwill [Roll Forward]
Below-market contracts assumed	5,400
West
Goodwill [Roll Forward]
Beginning balance	303,926	297,085
Acquisitions	29,006	15,491
Foreign currency translation adjustments	1,325	(8,650)
Ending balance	334,257	303,926
Accumulated impairment losses	(53,264)
West | Summit Materials, LLC
Goodwill [Roll Forward]
Beginning balance	303,926	297,085
Acquisitions	29,006	15,491
Foreign currency translation adjustments	1,325	(8,650)
Ending balance	334,257	303,926
Accumulated impairment losses	(53,264)
East
Goodwill [Roll Forward]
Beginning balance	98,308	98,089
Acquisitions	145,109	219
Ending balance	243,417	98,308
Accumulated impairment losses	(14,938)
East | Summit Materials, LLC
Goodwill [Roll Forward]
Beginning balance	98,308	98,089
Acquisitions	145,109	219
Ending balance	243,417	98,308
Accumulated impairment losses	(14,938)
Cement
Goodwill [Roll Forward]
Beginning balance	194,163	24,096
Acquisitions	10,375	170,067
Ending balance	204,538	194,163
Cement | Davenport Assets
Goodwill [Roll Forward]
Below-market contracts assumed	5,400
Cement | Summit Materials, LLC
Goodwill [Roll Forward]
Beginning balance	194,163	24,096
Acquisitions	10,375	170,067
Ending balance	$ 204,538	$ 194,163

Accounts Receivable, Net - Summ

Accounts Receivable, Net - Summary of Accounts Receivable, Net (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Jan. 02, 2016
Accounts, Notes, Loans and Financing Receivable [Line Items]
Trade accounts receivable	$ 152,845	$ 133,418
Retention receivables	12,117	13,217
Receivables from related parties	721	635
Accounts receivable	165,683	147,270
Less: Allowance for doubtful accounts	(3,306)	(1,726)
Accounts receivable, net	162,377	145,544
Summit Materials, LLC
Accounts, Notes, Loans and Financing Receivable [Line Items]
Trade accounts receivable	152,845	133,418
Retention receivables	12,117	13,217
Receivables from related parties	721	635
Accounts receivable	165,683	147,270
Less: Allowance for doubtful accounts	(3,306)	(1,726)
Accounts receivable, net	$ 162,377	$ 145,544

Inventories - Components of Inv

Inventories - Components of Inventories (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Jan. 02, 2016
Inventories
Aggregate stockpiles	$ 103,073	$ 86,236
Finished goods	35,071	14,840
Work in process	6,440	5,141
Raw materials	13,095	23,865
Total	157,679	130,082
Summit Materials, LLC
Inventories
Aggregate stockpiles	103,073	86,236
Finished goods	35,071	14,840
Work in process	6,440	5,141
Raw materials	13,095	23,865
Total	$ 157,679	$ 130,082

Property, Plant and Equipment67

Property, Plant and Equipment, Net - Components of Property, Plant and Equipment (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Jan. 02, 2016
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 1,931,006	$ 1,635,511
Less accumulated depreciation, depletion and amortization	(484,554)	(366,505)
Property, plant and equipment, net	1,446,452	1,269,006
Summit Materials, LLC
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	1,931,006	1,635,511
Less accumulated depreciation, depletion and amortization	(484,554)	(366,505)
Property, plant and equipment, net	1,446,452	1,269,006
Land (mineral bearing) and asset retirement costs
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	227,558	142,645
Land (mineral bearing) and asset retirement costs | Summit Materials, LLC
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	227,558	142,645
Land (non-mineral bearing)
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	146,099	151,008
Land (non-mineral bearing) | Summit Materials, LLC
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	146,099	151,008
Buildings and improvements
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	160,638	133,043
Buildings and improvements | Summit Materials, LLC
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	160,638	133,043
Plants, machinery and equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	965,522	860,085
Plants, machinery and equipment | Summit Materials, LLC
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	965,522	860,085
Mobile equipment and barges
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	307,885	231,523
Mobile equipment and barges | Summit Materials, LLC
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	307,885	231,523
Office equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	26,096	17,708
Office equipment | Summit Materials, LLC
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	26,096	17,708
Truck and auto fleet
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	32,236	24,539
Truck and auto fleet | Summit Materials, LLC
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	32,236	24,539
Landfill airspace and improvements
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	48,513	48,513
Landfill airspace and improvements | Summit Materials, LLC
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	48,513	48,513
Construction in progress
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	16,459	26,447
Construction in progress | Summit Materials, LLC
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 16,459	$ 26,447

Property, Plant and Equipment68

Property, Plant and Equipment, Net - Additional Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Jan. 02, 2016	Dec. 27, 2014
Property, Plant and Equipment [Line Items]
Depreciation, depletion and amortization expense	$ 147,736	$ 118,321	$ 86,955
Property, plant and equipment, net	1,446,452	1,269,006
Property, plant and equipment, accumulated depreciation, depletion and amortization	484,554	366,505
Capital lease obligations, current	11,766	15,263
2,017	13,600
2,018	17,600
2,019	5,700
2,020	2,600
2,021	700
Summit Materials, LLC
Property, Plant and Equipment [Line Items]
Depreciation, depletion and amortization expense	147,736	118,321	$ 86,955
Property, plant and equipment, net	1,446,452	1,269,006
Property, plant and equipment, accumulated depreciation, depletion and amortization	484,554	366,505
Capital lease obligations, current	11,766	15,263
2,017	13,600
2,018	17,600
2,019	5,700
2,020	2,600
2,021	700
Capital leases for equipment and building
Property, Plant and Equipment [Line Items]
Property, plant and equipment, net	49,800	47,000
Property, plant and equipment, accumulated depreciation, depletion and amortization	10,600	7,000
Capital leases for equipment and building | Summit Materials, LLC
Property, Plant and Equipment [Line Items]
Property, plant and equipment, net	49,800	47,000
Property, plant and equipment, accumulated depreciation, depletion and amortization	$ 10,600	7,000
Capital leases for equipment and building | Summit Materials, LLC | Maximum
Property, Plant and Equipment [Line Items]
Equipment leases terms	5 years
Building lease original term	30 years
Accrued expenses | Summit Materials, LLC
Property, Plant and Equipment [Line Items]
Capital lease obligations, current	$ 11,800	15,300
Accrued expenses | Capital leases for equipment and building
Property, Plant and Equipment [Line Items]
Capital lease obligations, current	11,800	15,300
Noncurrent liabilities | Summit Materials, LLC
Property, Plant and Equipment [Line Items]
Capital lease obligations, noncurrent	27,500	29,500
Noncurrent liabilities | Capital leases for equipment and building
Property, Plant and Equipment [Line Items]
Capital lease obligations, noncurrent	$ 27,500	$ 29,500

Accrued Expenses - Components o

Accrued Expenses - Components of Accrued Expenses (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Jan. 02, 2016
Schedule Of Accrued Expenses [Line Items]
Interest	$ 22,991	$ 19,591
Payroll and benefits	30,546	24,714
Capital lease obligations	11,766	15,263
Insurance	11,966	9,824
Non-income taxes	5,491	4,618
Professional fees	2,459	2,528
Other	26,386	16,404
Total	111,605	92,942
Summit Materials, LLC
Schedule Of Accrued Expenses [Line Items]
Interest	22,991	19,591
Payroll and benefits	30,546	24,714
Capital lease obligations	11,766	15,263
Insurance	11,966	9,824
Non-income taxes	5,491	4,618
Professional fees	2,459	2,528
Other	25,254	16,404
Total	$ 110,473	$ 92,942

Debt - Schedule of Debt (Detail

Debt - Schedule of Debt (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Mar. 08, 2016	Jan. 02, 2016
Debt
Total debt	$ 1,536,065		$ 1,291,858
Current portion of long-term debt	6,500		6,500
Long-term debt	1,529,565		1,285,358
Gross amount	1,540,250
Debt discount	4,185
Summit Materials, LLC
Debt
Total debt	1,536,065		1,291,858
Current portion of long-term debt	6,500		6,500
Long-term debt	1,529,565		1,285,358
Gross amount	1,540,250
Debt discount	4,185
Term Loan, due 2022
Debt
Total debt	637,658		643,693
Gross amount	640,300		646,800
Debt discount	2,600		3,100
Term Loan, due 2022 | Summit Materials, LLC
Debt
Total debt	637,658		643,693
Gross amount	640,300		646,800
Debt discount	2,600		3,100
8 1/2% Senior Notes, due 2022
Debt
Total debt	$ 250,000
Debt instrument interest rate (as a percent)	8.50%	8.50%
8 1/2% Senior Notes, due 2022 | Summit Materials, LLC
Debt
Total debt	$ 250,000
Debt instrument interest rate (as a percent)		8.50%
6 1/8% Senior Notes, due 2023
Debt
Total debt	648,407		648,165
Gross amount	650,000		650,000
Debt discount	$ 1,600		$ 1,800
Debt instrument interest rate (as a percent)	6.125%		6.125%
6 1/8% Senior Notes, due 2023 | Summit Materials, LLC
Debt
Total debt	$ 648,407		$ 648,165
Gross amount	650,000		650,000
Debt discount	$ 1,600		$ 1,800
Debt instrument interest rate (as a percent)	6.125%		6.125%

Debt - Schedule of Contractual

Debt - Schedule of Contractual Payments of Long-Term Debt (Details) $ in Thousands	Dec. 31, 2016USD ($)
Contractual payments of long-term debt
2,017	$ 6,500
2,018	4,875
2,019	6,500
2,020	8,125
2,021	6,500
Thereafter	1,507,750
Total	1,540,250
Less: Original issue net discount	(4,185)
Less: Capitalized loan costs	(15,109)
Total debt	1,520,956
Summit Materials, LLC
Contractual payments of long-term debt
2,017	6,500
2,018	4,875
2,019	6,500
2,020	8,125
2,021	6,500
Thereafter	1,507,750
Total	1,540,250
Less: Original issue net discount	(4,185)
Less: Capitalized loan costs	(15,109)
Total debt	$ 1,520,956

Debt - Senior Notes - Additiona

Debt - Senior Notes - Additional Information (Details) - USD ($) $ in Thousands	Mar. 08, 2016	Aug. 13, 2015	Jul. 17, 2015	Jan. 02, 2016	Dec. 31, 2016	Nov. 28, 2015	Aug. 22, 2015	Jul. 08, 2015	Apr. 25, 2015
Debt
Write off of deferred financing fees				$ 12,179
Davenport Assets
Debt
Purchase price		$ 450,000	$ 370,000	$ 370,000
8 1/2% Senior Notes, due 2022
Debt
Debt instrument, face amount	$ 250,000
Senior notes, interest rate (as a percent)	8.50%				8.50%
Percentage of par value of senior notes	100.00%
Proceeds net of related fees and expenses	$ 246,300
6 1/8% Senior Notes, due 2023
Debt
Senior notes, interest rate (as a percent)				6.125%	6.125%
10 1/2% Senior Notes, due 2020
Debt
Senior notes, aggregate principal amount redeemed						$ 153,800	$ 183,000	$ 336,800	$ 288,200
Charges on redemption				$ 56,500
Prepayment premium				66,600
Write off of deferred financing fees				11,900
Net benefit from the write-off the original issuance premium and discount				22,000
Issuers | 6 1/8% Senior Notes, due 2023
Debt
Debt instrument, face amount				$ 650,000
Senior notes, interest rate (as a percent)				6.125%
Issuers | 6 1/8% Senior Notes, due 2023, issued at par
Debt
Debt instrument, face amount				$ 350,000
Issuers | 6 1/8% Senior Notes, due 2023, , issued at 99.375% of par
Debt
Debt instrument, face amount				$ 300,000
Percentage of par value of senior notes				99.375%
Summit Materials, LLC
Debt
Write off of deferred financing fees				$ 12,179
Summit Materials, LLC | Davenport Assets
Debt
Purchase price		$ 450,000	$ 370,000
Summit Materials, LLC | 8 1/2% Senior Notes, due 2022
Debt
Debt instrument, face amount	$ 250,000
Senior notes, interest rate (as a percent)	8.50%
Summit Materials, LLC | 6 1/8% Senior Notes, due 2023
Debt
Senior notes, interest rate (as a percent)				6.125%	6.125%

Debt - Senior Secured Credit Fa

Debt - Senior Secured Credit Facilities - Additional Information (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2016USD ($)item	Jan. 02, 2016USD ($)	Dec. 27, 2014USD ($)	Jul. 17, 2015USD ($)	Jul. 16, 2015USD ($)	Mar. 11, 2015USD ($)	Mar. 10, 2015USD ($)
Debt
Financing fees recognized	$ 3,403	$ 3,390
Interest expense	83,800	73,600	$ 78,600
Summit Materials, LLC
Debt
Financing fees recognized	3,403	3,390
Interest expense	$ 83,800	73,600	$ 78,600
Summit Materials, LLC | Senior Secured Credit Facilities
Debt
Financing fees recognized		$ 800
First lien leverage ratio	4.75
Summit Materials, LLC | Term Loan, due 2022
Debt
Debt instrument, face amount	$ 650,000			$ 650,000	$ 422,000
Number of step downs | item	1
Step down (as a percent)	0.25%
Summit Materials, LLC | Term Loan, due 2022 | LIBOR
Debt
Basis spread on variable rate	3.25%
Interest rate floor (as a percent)	1.00%
Summit Materials, LLC | Term Loan, due 2022 | Base rate
Debt
Basis spread on variable rate	0.25%
Summit Materials, LLC | Revolving Credit Facility
Debt
Maximum borrowing capacity	$ 235,000					$ 235,000	$ 150,000
Remaining borrowing capacity	$ 209,400
Summit Materials, LLC | Revolving Credit Facility | LIBOR
Debt
Basis spread on variable rate	3.25%
Summit Materials, LLC | Revolving Credit Facility | Base rate
Debt
Basis spread on variable rate	2.25%
Summit Materials, LLC | Revolving Credit Facility | LIBOR Plus 1%
Debt
Basis spread on variable rate	2.25%
Percentage added to base rate	1.00%
Summit Materials, LLC | Revolving Credit Facility | Federal funds rate
Debt
Basis spread on variable rate	0.50%
Summit Materials, LLC | Letter of Credit
Debt
Amount outstanding	$ 25,600

Debt - Summary of Activity for

Debt - Summary of Activity for Deferred Financing Fees (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Jan. 02, 2016
Deferred finance costs
Beginning balance	$ 15,892	$ 17,215
Loan origination fees	5,801	14,246
Amortization	(3,403)	(3,390)
Write off of deferred financing fees		(12,179)
Ending balance	18,290	15,892
Summit Materials, LLC
Deferred finance costs
Beginning balance	15,892	17,215
Loan origination fees	5,801	14,246
Amortization	(3,403)	(3,390)
Write off of deferred financing fees		(12,179)
Ending balance	$ 18,290	$ 15,892

Debt - Other - Additional Infor

Debt - Other - Additional Information (Details) CAD in Millions	Jan. 15, 2015CAD
Canadian subsidiary credit agreement
Debt
Revolving credit commitment	CAD 6
Canadian subsidiary credit agreement, Capital equipment
Debt
Revolving credit commitment	CAD 0.5
Basis spread on variable rate	0.90%
Canadian subsidiary credit agreement, Guarantees
Debt
Revolving credit commitment	CAD 0.4
Prime rate | Canadian subsidiary credit agreement, Operating activities
Debt
Basis spread on variable rate	0.20%

Accumulated Other Comprehensi76

Accumulated Other Comprehensive Income (Loss) - Summary of Changes in Each Component of Accumulated Comprehensive Income Loss (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Jan. 02, 2016	Dec. 27, 2014
Changes in each component of accumulated other comprehensive loss
Beginning balance	$ 628,265
Postretirement curtailment adjustment			$ (1,346)
Ending balance	842,044	$ 628,265
Accumulated Other Comprehensive Operations
Changes in each component of accumulated other comprehensive loss
Beginning balance	(2,795)
Postretirement liability adjustment	(401)	(1,049)
Foreign currency translation adjustment	273	(3,379)
Loss on cash flow hedges	(128)	(465)
Ending balance	(2,249)	(2,795)
Change in retirement plans
Changes in each component of accumulated other comprehensive loss
Beginning balance	1,049
Postretirement liability adjustment	(401)	(1,049)
Ending balance	1,450	1,049
Foreign currency translation adjustment
Changes in each component of accumulated other comprehensive loss
Beginning balance	(3,379)
Foreign currency translation adjustment	273	(3,379)
Ending balance	(3,106)	(3,379)
Cash flow hedge adjustments
Changes in each component of accumulated other comprehensive loss
Beginning balance	(465)
Loss on cash flow hedges	(128)	(465)
Ending balance	(593)	(465)
Summit Materials, LLC
Changes in each component of accumulated other comprehensive loss
Postretirement curtailment adjustment			(1,346)
Summit Materials, LLC | Accumulated Other Comprehensive Operations
Changes in each component of accumulated other comprehensive loss
Beginning balance	(28,466)	(15,546)	(6,045)
Postretirement curtailment adjustment			(942)
Postretirement liability adjustment	426	2,123	(2,743)
Foreign currency translation adjustment	2,125	(14,099)	(5,816)
Loss on cash flow hedges	(1,529)	(944)
Ending balance	(27,444)	(28,466)	(15,546)
Summit Materials, LLC | Change in retirement plans
Changes in each component of accumulated other comprehensive loss
Beginning balance	(7,607)	(9,730)	(6,045)
Postretirement curtailment adjustment			(942)
Postretirement liability adjustment	426	2,123	(2,743)
Ending balance	(7,181)	(7,607)	(9,730)
Summit Materials, LLC | Foreign currency translation adjustment
Changes in each component of accumulated other comprehensive loss
Beginning balance	(19,915)	(5,816)
Foreign currency translation adjustment	2,125	(14,099)	(5,816)
Ending balance	(17,790)	(19,915)	$ (5,816)
Summit Materials, LLC | Cash flow hedge adjustments
Changes in each component of accumulated other comprehensive loss
Beginning balance	(944)
Loss on cash flow hedges	(1,529)	(944)
Ending balance	$ (2,473)	$ (944)

Income Taxes - Components of In

Income Taxes - Components of Income Tax Benefit (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Jan. 02, 2016	Dec. 27, 2014
Provision for income taxes:
Current	$ 2,835	$ 1,605	$ (905)
Deferred	(8,134)	(19,868)	(6,078)
Income tax benefit	(5,299)	(18,263)	(6,983)
Valuation allowance	502,839	263,825	2,523
Summit Materials, LLC
Provision for income taxes:
Current	2,835	1,605	(905)
Deferred	(8,117)	(19,868)	(6,078)
Income tax benefit	(5,282)	(18,263)	$ (6,983)
Valuation allowance	$ 2,677	$ 2,523

Income Taxes - Schedule of Inco

Income Taxes - Schedule of Income Tax Benefit (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Jan. 02, 2016	Dec. 27, 2014
Effective Income Tax Rate Continuing Operations Tax Rate Reconciliation [Line Items]
Income tax benefit at federal statutory tax rate	$ 14,290	$ (6,718)	$ (4,643)
Less: Income tax (benefit) expense at federal statutory tax rate for LLC entities	(10,608)	(10,747)	(2,272)
State and local income taxes	2,490	(2,389)	(224)
Permanent differences	(674)	2,147	(129)
Effective tax rate change	(1,432)	10	(241)
Valuation allowance	291,151		1,693
Impact of LP Unit ownership change	(304,599)
Other	4,083	(566)	(1,167)
Income tax benefit	$ (5,299)	(18,263)	(6,983)
U.S. statutory rate	35.00%
Summit Materials, LLC
Effective Income Tax Rate Continuing Operations Tax Rate Reconciliation [Line Items]
Income tax benefit at federal statutory tax rate	$ 19,882	(6,412)	(4,643)
Less: Income tax (benefit) expense at federal statutory tax rate for LLC entities	(21,042)	(9,908)	(2,272)
State and local income taxes	1,279	(2,389)	(224)
Permanent differences	(1,726)	2,147	(129)
Effective tax rate change	(1,432)	10	(241)
Valuation allowance	148		1,693
Other	(2,391)	(1,711)	(1,167)
Income tax benefit	$ (5,282)	$ (18,263)	$ (6,983)
U.S. statutory rate	35.00%

Income Taxes - Components of Ne

Income Taxes - Components of Net Deferred Income Tax Liability (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Jan. 02, 2016	Dec. 27, 2014
Deferred tax (liabilities) assets:
Net intangible assets	$ 591,464	$ 227,506
Accelerated depreciation	(184,794)	(23,781)
Net operating loss	71,379	38,279
Investment in limited partnership	(13,633)	(14,304)
Mining reclamation reserve	1,220	3,476
Working capital (e.g., accrued compensation, prepaid assets)	41,529	10,730
Deferred tax liabilities, net	507,165	241,906
Less valuation allowance on loss carryforwards	(502,839)	(263,825)	$ (2,523)
Net deferred tax liability, net		(21,919)
Net deferred tax asset, net	4,326
Summit Materials, LLC
Deferred tax (liabilities) assets:
Net intangible assets	(999)	(880)
Accelerated depreciation	(58,094)	(35,221)
Net operating loss	24,884	25,767
Investment in limited partnership	(12,899)	(13,135)
Mining reclamation reserve	582	2,411
Working capital (e.g., accrued compensation, prepaid assets)	(1,386)	(1,662)
Deferred tax liabilities, net	(45,140)	(19,396)
Less valuation allowance on loss carryforwards	(2,677)	(2,523)
Net deferred tax liability, net	$ (47,817)	$ (21,919)

Income Taxes - Deferred Tax Ass

Income Taxes - Deferred Tax Assets and Tax Receivable Agreement (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Jan. 02, 2016	Dec. 27, 2014
Income Taxes
Income tax benefit	$ (5,299)	$ (18,263)	$ (6,983)
Tax receivable agreement expense	$ 14,938
Number of Summit LP units purchased by Company, newly issued units (in shares)	45,124,528	18,675,000
Deferred tax asset, Investment in limited partnership	$ 769,700
Tax benefit deemed probable	69,700
Alternative minimum tax credit	200
Deferred tax liability, fixed assets	$ 184,794	$ 23,781
Liability percentage to holders	85.00%
Valuation Allowance
Valuation allowance	$ (502,839)	(263,825)	(2,523)
Exchange of L.P. Units	(256,588)	(261,302)
Loss carryforwards	(33,100)	(31,173)
Release	$ 50,674
Tax Receivable Agreement
Income Taxes
Percentage of benefits to be paid on tax receivable agreement	85.00%
Liability due to former holders of LP Units	$ 59,200
Tax receivable agreement expense	14,900
Tax Receivable Agreement | Other noncurrent liabilities
Income Taxes
Liability due to former holders of LP Units	58,100
Tax Receivable Agreement | Accrued expenses.
Income Taxes
Liability due to former holders of LP Units	1,100
Federal
Income Taxes
Net operating loss carryforwards	192,400
Summit Materials, LLC
Income Taxes
Income tax benefit	(5,282)	(18,263)	$ (6,983)
Deferred tax liability, fixed assets	58,094	35,221
Operating loss carryforwards valuation allowance recorded	2,700	2,500
Valuation Allowance
Valuation allowance	(2,677)	(2,523)
Summit Materials, LLC | Federal
Valuation Allowance
Loss carryforwards	(63,700)
Summit Materials, LLC | State and Local Jurisdiction
Valuation Allowance
Loss carryforwards	(72,500)
Summit Holdings LP
Income Taxes
Distributions to LP Unitholders	$ 13,000	$ 28,700

Employee Benefit Plans - Additi

Employee Benefit Plans - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Jan. 02, 2016	Dec. 27, 2014
Defined Benefit Plan Disclosure [Line Items]
Expense for defined contribution plans	$ 8.6	$ 7.1	$ 3.8
Summit Materials, LLC
Defined Benefit Plan Disclosure [Line Items]
Expense for defined contribution plans	$ 8.6	$ 7.1	$ 3.8

Employee Benefit Plans - Obliga

Employee Benefit Plans - Obligations and Funded Status (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Jan. 02, 2016	Dec. 27, 2014
Change in fair value of plan assets:
Beginning of period	$ 18,337
End of period	18,395	$ 18,337
Summit Materials, LLC
Change in benefit obligations:
Beginning of period	13,458
Service cost	230
Interest cost	470
Actuarial loss (gain)	(682)
Change in plan provision	65
Benefits paid	(771)
End of period	12,770	13,458
Change in fair value of plan assets:
Employer contributions	771
Benefits paid	(771)
Funded status of plans	(12,770)
Current liabilities	(844)
Noncurrent liabilities	(11,926)
Liability recognized	(12,770)
Amounts recognized in accumulated other comprehensive income
Net actuarial loss	3,060
Prior service cost	(1,968)
Total amount recognized	1,092
Pension Benefits
Change in benefit obligations:
Beginning of period	27,914	28,909
Service cost	279	159	$ 75
Interest cost	1,049	1,041	1,081
Actuarial loss (gain)	22	(1,464)
Change in plan provision		908
Benefits paid	(1,656)	(1,639)
End of period	27,608	27,914	28,909
Change in fair value of plan assets:
Beginning of period	18,336	18,872
Actual return on plan assets	719	(63)
Employer contributions	996	1,166
Benefits paid	(1,656)	(1,639)
End of period	18,395	18,336	18,872
Funded status of plans	(9,213)	(9,578)
Noncurrent liabilities	(9,213)	(9,578)
Liability recognized	(9,213)	(9,578)
Amounts recognized in accumulated other comprehensive income
Net actuarial loss	9,248	9,024
Total amount recognized	9,248	9,024
Pension Benefits | Summit Materials, LLC
Change in benefit obligations:
Beginning of period	27,914	28,909
Service cost	279	159	75
Interest cost	1,049	1,041	1,081
Actuarial loss (gain)	22	(1,464)
Change in plan provision		908
Benefits paid	(1,656)	(1,639)
End of period	27,608	27,914	28,909
Change in fair value of plan assets:
Beginning of period	18,336	18,872
Actual return on plan assets	719	(63)
Employer contributions	996	1,166
Benefits paid	(1,656)	(1,639)
End of period	18,395	18,336	18,872
Funded status of plans	(9,213)	(9,578)
Noncurrent liabilities	(9,213)	(9,578)
Liability recognized	(9,213)	(9,578)
Amounts recognized in accumulated other comprehensive income
Net actuarial loss	9,248	9,024
Total amount recognized	9,248	9,024
Healthcare & Life Ins
Change in benefit obligations:
Beginning of period	13,458	13,356
Service cost	230	149	106
Interest cost	470	447	493
Actuarial loss (gain)	(682)	(1,720)
Change in plan provision	65	1,896
Benefits paid	(771)	(670)
End of period	12,770	13,458	13,356
Change in fair value of plan assets:
Employer contributions	771	670
Benefits paid	(771)	(670)
Funded status of plans	(12,770)	(13,458)
Current liabilities	(844)	(964)
Noncurrent liabilities	(11,926)	(12,494)
Liability recognized	(12,770)	(13,458)
Amounts recognized in accumulated other comprehensive income
Net actuarial loss	3,060	3,949
Prior service cost	(1,968)	(2,206)
Total amount recognized	1,092	1,743
Healthcare & Life Ins | Summit Materials, LLC
Change in benefit obligations:
Beginning of period	13,458	13,356
Service cost	230	149	106
Interest cost	$ 470	447	493
Actuarial loss (gain)		(1,720)
Change in plan provision		1,896
Benefits paid		(670)
End of period		13,458	$ 13,356
Change in fair value of plan assets:
Employer contributions		670
Benefits paid		(670)
Funded status of plans		(13,458)
Current liabilities		(964)
Noncurrent liabilities		(12,494)
Liability recognized		(13,458)
Amounts recognized in accumulated other comprehensive income
Net actuarial loss		3,949
Prior service cost		(2,206)
Total amount recognized		$ 1,743

Employee Benefit Plans - Amount

Employee Benefit Plans - Amounts Recognized in Other Comprehensive (Gain) Loss (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Jan. 02, 2016	Dec. 27, 2014
Amounts recognized in other comprehensive (income) loss:
Total amount recognized	$ (426)	$ (2,123)	$ 3,919
Summit Materials, LLC
Amounts recognized in other comprehensive (income) loss:
Total amount recognized	(426)	(2,123)	3,919
Pension Benefits
Amounts recognized in other comprehensive (income) loss:
Net actuarial (loss) gain	688	(16)	4,650
Amortization of gain	(463)	(326)	(117)
Total amount recognized	225	(342)	4,533
Pension Benefits | Summit Materials, LLC
Amounts recognized in other comprehensive (income) loss:
Net actuarial (loss) gain	688	(16)	4,650
Amortization of gain	(463)	(326)	(117)
Total amount recognized	225	(342)	4,533
Healthcare & Life Ins
Amounts recognized in other comprehensive (income) loss:
Net actuarial (loss) gain	(682)	(1,720)	1,992
Prior service cost	64		(2,553)
Amortization of prior year service cost	174	174	174
Curtailment benefit			1,346
Amortization of gain	(207)	(235)	(227)
Total amount recognized	(651)	(1,781)	732
Healthcare & Life Ins | Summit Materials, LLC
Amounts recognized in other comprehensive (income) loss:
Net actuarial (loss) gain	(682)	(1,720)	1,992
Prior service cost	64		(2,553)
Amortization of prior year service cost	174	174	174
Curtailment benefit			1,346
Amortization of gain	(207)	(235)	(227)
Total amount recognized	$ (651)	$ (1,781)	$ 732

Employee Benefit Plans - Compon

Employee Benefit Plans - Components of Net Periodic Benefit Cost (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Jan. 02, 2016	Dec. 27, 2014
Summit Materials, LLC
Components of net periodic benefit cost:
Service cost	$ 230
Interest cost	470
Pension Benefits
Components of net periodic benefit cost:
Service cost	279	$ 159	$ 75
Interest cost	1,049	1,041	1,081
Amortization of gain	463	326	117
Expected return on plan assets	(1,386)	(1,385)	(1,378)
Net periodic benefit cost	405	141	(105)
Pension Benefits | Summit Materials, LLC
Components of net periodic benefit cost:
Service cost	279	159	75
Interest cost	1,049	1,041	1,081
Amortization of gain	463	326	117
Expected return on plan assets	(1,386)	(1,385)	(1,378)
Net periodic benefit cost	405	141	(105)
Healthcare & Life Ins
Components of net periodic benefit cost:
Service cost	230	149	106
Interest cost	470	447	493
Amortization of gain	207	235	227
Curtailments			(1,346)
Amortization of prior service credit	(174)	(174)	(174)
Net periodic benefit cost	733	657	(694)
Healthcare & Life Ins | Summit Materials, LLC
Components of net periodic benefit cost:
Service cost	230	149	106
Interest cost	470	447	493
Amortization of gain	207	235	227
Curtailments			(1,346)
Amortization of prior service credit	(174)	(174)	(174)
Net periodic benefit cost	$ 733	$ 657	$ (694)

Employee Benefit Plans - Weight

Employee Benefit Plans - Weighted-Average Assumptions Used to Determine Benefit Obligations (Detail)	12 Months Ended
	Dec. 31, 2016	Jan. 02, 2016
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Expected long-term rate of return on plan assets, benefit obligation	7.00%	7.30%
Pension Benefits | Summit Materials, LLC
Defined Benefit Plan Disclosure [Line Items]
Expected long-term rate of return on plan assets, benefit obligation	7.00%	7.30%
Pension Benefits | Minimum
Defined Benefit Plan Disclosure [Line Items]
Discount rate	3.61%	3.74%
Pension Benefits | Minimum | Summit Materials, LLC
Defined Benefit Plan Disclosure [Line Items]
Discount rate	3.61%	3.74%
Pension Benefits | Maximum
Defined Benefit Plan Disclosure [Line Items]
Discount rate	3.81%	3.97%
Pension Benefits | Maximum | Summit Materials, LLC
Defined Benefit Plan Disclosure [Line Items]
Discount rate	3.81%	3.97%
Healthcare & Life Ins | Minimum
Defined Benefit Plan Disclosure [Line Items]
Discount rate	3.32%	3.34%
Healthcare & Life Ins | Minimum | Summit Materials, LLC
Defined Benefit Plan Disclosure [Line Items]
Discount rate	3.32%	3.34%
Healthcare & Life Ins | Maximum
Defined Benefit Plan Disclosure [Line Items]
Discount rate	3.65%	3.80%
Healthcare & Life Ins | Maximum | Summit Materials, LLC
Defined Benefit Plan Disclosure [Line Items]
Discount rate	3.65%	3.80%

Employee Benefit Plans - Weig86

Employee Benefit Plans - Weighted-Average Assumptions Used to Determine Net Periodic Benefit Cost (Detail)	12 Months Ended
	Dec. 31, 2016	Jan. 02, 2016	Dec. 27, 2014
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Expected long-term rate of return on plan assets, net periodic benefit cost	7.30%	7.30%	7.50%
Pension Benefits | Summit Materials, LLC
Defined Benefit Plan Disclosure [Line Items]
Expected long-term rate of return on plan assets, net periodic benefit cost	7.30%	7.30%	7.50%
Pension Benefits | Minimum
Defined Benefit Plan Disclosure [Line Items]
Discount rate	3.74%	3.50%	4.21%
Pension Benefits | Minimum | Summit Materials, LLC
Defined Benefit Plan Disclosure [Line Items]
Discount rate	3.74%	3.50%	4.21%
Pension Benefits | Maximum
Defined Benefit Plan Disclosure [Line Items]
Discount rate	3.97%	3.98%	4.46%
Pension Benefits | Maximum | Summit Materials, LLC
Defined Benefit Plan Disclosure [Line Items]
Discount rate	3.97%	3.98%	4.46%
Healthcare & Life Ins
Defined Benefit Plan Disclosure [Line Items]
Discount rate			4.33%
Healthcare & Life Ins | Summit Materials, LLC
Defined Benefit Plan Disclosure [Line Items]
Discount rate			4.33%
Healthcare & Life Ins | Minimum
Defined Benefit Plan Disclosure [Line Items]
Discount rate	3.34%	3.39%
Healthcare & Life Ins | Minimum | Summit Materials, LLC
Defined Benefit Plan Disclosure [Line Items]
Discount rate	3.34%	3.39%
Healthcare & Life Ins | Maximum
Defined Benefit Plan Disclosure [Line Items]
Discount rate	3.80%	3.52%
Healthcare & Life Ins | Maximum | Summit Materials, LLC
Defined Benefit Plan Disclosure [Line Items]
Discount rate	3.80%	3.52%

Employee Benefit Plans - Effect

Employee Benefit Plans - Effects of One Percentage-Point Change in Assumed Health Care Cost Trend Rates (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Jan. 02, 2016
Compensation and Retirement Disclosure [Abstract]
Total service cost and interest cost components, Increase	$ 55	$ 45
APBO, Increase	1,197	1,302
Total service cost and interest cost components, Decrease	(47)	(36)
APBO, Decrease	$ (1,038)	$ (1,121)
Summit Materials, LLC
Compensation and Retirement Disclosure [Abstract]
Assumed health care cost trend rates	8.00%	8.00%
Assumed health care cost, grading	4.50%	4.50%

Employee Benefit Plans - Target

Employee Benefit Plans - Target Allocaiton of Company's Pension Plans' Assets (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Jan. 02, 2016
Pension Benefits | Level 3
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan fair value of investments	$ 0	$ 0
Pension Benefits | Equity Securities
Defined Benefit Plan Disclosure [Line Items]
Target allocation	30.00%
Pension Benefits | Fixed Income Securities
Defined Benefit Plan Disclosure [Line Items]
Target allocation	63.00%
Pension Benefits | Cash
Defined Benefit Plan Disclosure [Line Items]
Target allocation	5.00%
Pension Benefits | Precious Metals
Defined Benefit Plan Disclosure [Line Items]
Target allocation	2.00%
Summit Materials, LLC
Defined Benefit Plan Disclosure [Line Items]
Expected contribution to plans in 2017	$ 1,700
Summit Materials, LLC | Pension Benefits | Level 3
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan fair value of investments	$ 0	$ 0
Summit Materials, LLC | Pension Benefits | Equity Securities
Defined Benefit Plan Disclosure [Line Items]
Target allocation	30.00%
Summit Materials, LLC | Pension Benefits | Fixed Income Securities
Defined Benefit Plan Disclosure [Line Items]
Target allocation	63.00%
Summit Materials, LLC | Pension Benefits | Cash
Defined Benefit Plan Disclosure [Line Items]
Target allocation	5.00%
Summit Materials, LLC | Pension Benefits | Precious Metals
Defined Benefit Plan Disclosure [Line Items]
Target allocation	2.00%

Employee Benefit Plans - Fair V

Employee Benefit Plans - Fair Value of Company's Pension Plans' Assets (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Jan. 02, 2016	Dec. 27, 2014
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Total fair value	$ 18,395	$ 18,337
Intermediate - Government [Member]
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Total fair value	1,770	1,410
Intermediate - Corporate [Member]
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Total fair value	2,658	3,376
Short Term - Government [Member]
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Total fair value	912	390
Short Term - Corporate [Member]
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Total fair value	3,613	5,571
U.S. Large Cap Value [Member]
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Total fair value	1,181	1,148
U.S. Large Cap Growth [Member]
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Total fair value	1,103	1,153
U.S. Mid Cap Value [Member]
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Total fair value	577	557
U.S. Mid Cap Growth [Member]
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Total fair value	546	569
U.S. Small Cap Value [Member]
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Total fair value	551	554
U.S. Small Cap Growth [Member]
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Total fair value	540	554
Managed Futures [Member]
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Total fair value	366
International [Member]
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Total fair value	1,099	1,118
Emerging Markets [Member]
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Total fair value	359
Commodities Broad Basket [Member]
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Total fair value	707
Cash
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Total fair value	2,094	1,592
Precious Metals
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Total fair value	319	345
Pension Benefits
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Total fair value	18,395	18,336	$ 18,872
Pension Benefits | Summit Materials, LLC
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Total fair value	18,395	18,336	$ 18,872
Pension Benefits | Intermediate - Government [Member] | Summit Materials, LLC
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Total fair value	1,770	1,410
Pension Benefits | Intermediate - Corporate [Member] | Summit Materials, LLC
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Total fair value	2,658	3,376
Pension Benefits | Short Term - Government [Member] | Summit Materials, LLC
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Total fair value	912	390
Pension Benefits | Short Term - Corporate [Member] | Summit Materials, LLC
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Total fair value	3,613	5,571
Pension Benefits | U.S. Large Cap Value [Member] | Summit Materials, LLC
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Total fair value	1,181	1,148
Pension Benefits | U.S. Large Cap Growth [Member] | Summit Materials, LLC
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Total fair value	1,103	1,153
Pension Benefits | U.S. Mid Cap Value [Member] | Summit Materials, LLC
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Total fair value	577	557
Pension Benefits | U.S. Mid Cap Growth [Member] | Summit Materials, LLC
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Total fair value	546	569
Pension Benefits | U.S. Small Cap Value [Member] | Summit Materials, LLC
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Total fair value	551	554
Pension Benefits | U.S. Small Cap Growth [Member] | Summit Materials, LLC
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Total fair value	540	554
Pension Benefits | Managed Futures [Member] | Summit Materials, LLC
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Total fair value	366
Pension Benefits | International [Member] | Summit Materials, LLC
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Total fair value	1,099	1,118
Pension Benefits | Emerging Markets [Member] | Summit Materials, LLC
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Total fair value	359
Pension Benefits | Commodities Broad Basket [Member] | Summit Materials, LLC
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Total fair value	707
Pension Benefits | Cash | Summit Materials, LLC
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Total fair value	2,094	1,592
Pension Benefits | Precious Metals | Summit Materials, LLC
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Total fair value	319	345
Quoted Prices in Active Markets for Identical Assets (Level 1)
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Total fair value	9,442	7,590
Quoted Prices in Active Markets for Identical Assets (Level 1) | U.S. Large Cap Value [Member]
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Total fair value	1,181	1,148
Quoted Prices in Active Markets for Identical Assets (Level 1) | U.S. Large Cap Growth [Member]
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Total fair value	1,103	1,153
Quoted Prices in Active Markets for Identical Assets (Level 1) | U.S. Mid Cap Value [Member]
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Total fair value	577	557
Quoted Prices in Active Markets for Identical Assets (Level 1) | U.S. Mid Cap Growth [Member]
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Total fair value	546	569
Quoted Prices in Active Markets for Identical Assets (Level 1) | U.S. Small Cap Value [Member]
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Total fair value	551	554
Quoted Prices in Active Markets for Identical Assets (Level 1) | U.S. Small Cap Growth [Member]
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Total fair value	540	554
Quoted Prices in Active Markets for Identical Assets (Level 1) | Managed Futures [Member]
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Total fair value	366
Quoted Prices in Active Markets for Identical Assets (Level 1) | International [Member]
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Total fair value	1,099	1,118
Quoted Prices in Active Markets for Identical Assets (Level 1) | Emerging Markets [Member]
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Total fair value	359
Quoted Prices in Active Markets for Identical Assets (Level 1) | Commodities Broad Basket [Member]
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Total fair value	707
Quoted Prices in Active Markets for Identical Assets (Level 1) | Cash
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Total fair value	2,094	1,592
Quoted Prices in Active Markets for Identical Assets (Level 1) | Precious Metals
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Total fair value	319	345
Quoted Prices in Active Markets for Identical Assets (Level 1) | Pension Benefits | Summit Materials, LLC
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Total fair value	9,442	7,590
Quoted Prices in Active Markets for Identical Assets (Level 1) | Pension Benefits | U.S. Large Cap Value [Member] | Summit Materials, LLC
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Total fair value	1,181	1,148
Quoted Prices in Active Markets for Identical Assets (Level 1) | Pension Benefits | U.S. Large Cap Growth [Member] | Summit Materials, LLC
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Total fair value	1,103	1,153
Quoted Prices in Active Markets for Identical Assets (Level 1) | Pension Benefits | U.S. Mid Cap Value [Member] | Summit Materials, LLC
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Total fair value	577	557
Quoted Prices in Active Markets for Identical Assets (Level 1) | Pension Benefits | U.S. Mid Cap Growth [Member] | Summit Materials, LLC
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Total fair value	546	569
Quoted Prices in Active Markets for Identical Assets (Level 1) | Pension Benefits | U.S. Small Cap Value [Member] | Summit Materials, LLC
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Total fair value	551	554
Quoted Prices in Active Markets for Identical Assets (Level 1) | Pension Benefits | U.S. Small Cap Growth [Member] | Summit Materials, LLC
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Total fair value	540	554
Quoted Prices in Active Markets for Identical Assets (Level 1) | Pension Benefits | Managed Futures [Member] | Summit Materials, LLC
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Total fair value	366
Quoted Prices in Active Markets for Identical Assets (Level 1) | Pension Benefits | International [Member] | Summit Materials, LLC
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Total fair value	1,099	1,118
Quoted Prices in Active Markets for Identical Assets (Level 1) | Pension Benefits | Emerging Markets [Member] | Summit Materials, LLC
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Total fair value	359
Quoted Prices in Active Markets for Identical Assets (Level 1) | Pension Benefits | Commodities Broad Basket [Member] | Summit Materials, LLC
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Total fair value	707
Quoted Prices in Active Markets for Identical Assets (Level 1) | Pension Benefits | Cash | Summit Materials, LLC
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Total fair value	2,094	1,592
Quoted Prices in Active Markets for Identical Assets (Level 1) | Pension Benefits | Precious Metals | Summit Materials, LLC
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Total fair value	319	345
Level 2
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Total fair value	8,953	10,747
Level 2 | Intermediate - Government [Member]
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Total fair value	1,770	1,410
Level 2 | Intermediate - Corporate [Member]
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Total fair value	2,658	3,376
Level 2 | Short Term - Government [Member]
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Total fair value	912	390
Level 2 | Short Term - Corporate [Member]
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Total fair value	3,613	5,571
Level 2 | Pension Benefits | Summit Materials, LLC
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Total fair value	8,953	10,747
Level 2 | Pension Benefits | Intermediate - Government [Member] | Summit Materials, LLC
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Total fair value	1,770	1,410
Level 2 | Pension Benefits | Intermediate - Corporate [Member] | Summit Materials, LLC
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Total fair value	2,658	3,376
Level 2 | Pension Benefits | Short Term - Government [Member] | Summit Materials, LLC
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Total fair value	912	390
Level 2 | Pension Benefits | Short Term - Corporate [Member] | Summit Materials, LLC
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Total fair value	$ 3,613	$ 5,571

Employee Benefit Plans - Estima

Employee Benefit Plans - Estimated Benefit Payments (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2016USD ($)
Summit Materials, LLC
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Expected contribution to plans in 2017	$ 1,700
Pension Benefits
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
2,017	1,777
2,018	1,813
2,019	1,817
2,020	1,793
2,021	1,762
2022 - 2026	8,590
Pension Benefits | Summit Materials, LLC
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
2,017	1,777
2,018	1,813
2,019	1,817
2,020	1,793
2,021	1,762
2022 - 2026	8,590
Healthcare & Life Ins
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
2,017	844
2,018	882
2,019	869
2,020	910
2,021	898
2022 - 2026	4,579
Healthcare & Life Ins | Summit Materials, LLC
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
2,017	844
2,018	882
2,019	869
2,020	910
2,021	898
2022 - 2026	$ 4,579

Accrued Mining and Landfill R91

Accrued Mining and Landfill Reclamation - Additional Information (Detail) - USD ($) $ in Millions	Dec. 31, 2016	Jan. 02, 2016
Asset Retirement Obligations [Line Items]
Anticipated costs	$ 63.6	$ 56.7
Accrued expenses
Asset Retirement Obligations [Line Items]
Asset retirement obligation, current	5.1	2
Summit Materials, LLC
Asset Retirement Obligations [Line Items]
Asset retirement obligation, current	5.1	2
Anticipated costs	$ 63.6	$ 56.7

Accrued Mining and Landfill R92

Accrued Mining and Landfill Reclamation - Activity for Asset Retirement Obligations (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Jan. 02, 2016	Dec. 27, 2014
Asset Retirement Obligation, Activity
Beginning balance	$ 20,735	$ 18,310
Acquired obligations	835	745
Change in cost estimate	3,055	907
Settlement of reclamation obligations	(2,283)	(689)
Additional liabilities incurred		60
Accretion expense	1,564	1,402	$ 871
Ending balance	23,906	20,735	18,310
Summit Materials, LLC
Asset Retirement Obligation, Activity
Beginning balance	20,735	18,310
Acquired obligations	835	745
Change in cost estimate	3,055	907
Settlement of reclamation obligations	(2,283)	(689)
Additional liabilities incurred		60
Accretion expense	1,564	1,402	871
Ending balance	$ 23,906	$ 20,735	$ 18,310

Net Income Per Share - Schedule

Net Income Per Share - Schedule of Basic to Diluted Income Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	Jan. 10, 2017	Dec. 31, 2016	Oct. 01, 2016	Jul. 02, 2016	Apr. 02, 2016	Jan. 02, 2016	Sep. 26, 2015	Jun. 27, 2015	Mar. 28, 2015	Dec. 31, 2016	Jan. 02, 2016	Dec. 27, 2014
Reconciliation of basic to diluted loss per share
Net income (loss) attributable to Summit Inc.		$ (290)	$ 44,820	$ 13,371	$ (21,118)	$ 23,363	$ 14,711	$ (205)	$ (10,151)	$ 36,783	$ 27,718
Add: Noncontrolling interest impact of LP Unit conversion											17,803
Diluted net income attributable to Summit Inc.										$ 36,783	$ 45,521
Number of Summit LP units purchased by Company, newly issued units (in shares)										45,124,528	18,675,000
LP Units
Reconciliation of basic to diluted loss per share
Add: weighted average of LP Units											50,059,648
Anti dilutive shares excluded from calculation of earnings per share										32,327,907	2,265,584
Stock options
Reconciliation of basic to diluted loss per share
Add: Share-based payment arrangements										140,142
Warrants
Reconciliation of basic to diluted loss per share
Add: warrants										16,123	37,714
Restricted stock units
Reconciliation of basic to diluted loss per share
Add: Share-based payment arrangements										240,633	7,523
Performance stock units
Reconciliation of basic to diluted loss per share
Add: Share-based payment arrangements										86,568
Common Class A
Reconciliation of basic to diluted loss per share
Weighted average shares of Class A common stock outstanding										68,833,986	39,367,381
Basic income (loss) per share										$ 0.53	$ 0.70
Weighted average dilutive shares outstanding										69,317,452	89,472,266
Diluted earnings per share										$ 0.53	$ 0.51
Anti dilutive shares excluded from calculation of earnings per share	10,000,000									1,135,962	735,108
Summit Materials, LLC
Reconciliation of basic to diluted loss per share
Net income (loss) attributable to Summit Inc.										$ 62,071	$ 4,182	$ (8,777)

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended				48 Months Ended
	Dec. 31, 2012	Dec. 29, 2012	Dec. 31, 2011	Dec. 31, 2011	Dec. 31, 2016	Jan. 02, 2016
Contingencies
Amount funded for loss incurred by joint venture	$ 4		$ 4.8		$ 8.8
Recognized losses on indemnification agreement		$ 8		$ 1.9
Other noncurrent liabilities
Contingencies
Accrual recorded in other noncurrent liabilities					4.3	$ 4.3
Summit Materials, LLC
Contingencies
Amount funded for loss incurred by joint venture		4		4.8	8.8
Recognized losses on indemnification agreement		$ 8		$ 1.9
Accrual recorded in other noncurrent liabilities					4.3	4.3
Asset retirement obligation, current					$ 5.1	$ 2

Related Party Transactions - Ad

Related Party Transactions - Additional Information (Details) - USD ($)

Aug. 13, 2015

Aug. 11, 2015

Jul. 17, 2015

Apr. 16, 2015

Mar. 17, 2015

Mar. 11, 2015

Aug. 31, 2015

Mar. 17, 2015

Dec. 31, 2016

Jan. 02, 2016

Dec. 27, 2014

Mar. 31, 2016

Nov. 30, 2015

Jul. 31, 2015

Related Party Transactions

Assets sold to related party

$ 2,300,000

IPO | Common Class A

Related Party Transactions

Issuance of Shares (in shares)

25,555,555

Follow on Public Offering | Common Class A

Related Party Transactions

Issuance of Shares (in shares)

22,425,000

Davenport Assets

Related Party Transactions

Cash paid for acquisitions

$ 450,000,000

$ 370,000,000

$ 370,000,000

Deferred purchase price associated with acquisition

80,000,000

Davenport Assets | Follow on Public Offering

Related Party Transactions

Cash paid for acquisitions

80,000,000

Summit Materials, LLC

Related Party Transactions

Assets sold to related party

2,300,000

Summit Materials, LLC | Davenport Assets

Related Party Transactions

Cash paid for acquisitions

450,000,000

370,000,000

Deferred purchase price associated with acquisition

$ 80,000,000

Summit Materials, LLC | Davenport Assets | Follow on Public Offering

Related Party Transactions

Cash paid for acquisitions

$ 80,000,000

Blackstone Management Partners L.L.C. | Management fee

Related Party Transactions

Annual management fee

$ 300,000

Annual management fee, as a percent of annual consolidated profit

2.00%

Related party expense

$ 4,400,000

$ 1,000,000

Related party benefit, cost adjustment

1,400,000

Blackstone Management Partners L.L.C. | Management fee | Summit Materials, LLC

Related Party Transactions

Annual management fee

$ 300,000

Annual management fee, as a percent of annual consolidated profit

2.00%

Related party expense

$ 1,000,000

4,400,000

Related party benefit, cost adjustment

$ 1,400,000

Affiliates of the Sponsors Blackstone Management Partners and Silverhawk Summit | Termination fee paid to related parties | IPO

Related Party Transactions

Related party expense

$ 13,800,000

Affiliates of BMP

Related Party Transactions

Related party expense

13,400,000

Affiliates of BMP | Transaction fee

Related Party Transactions

Related party expense

$ 3,900,000

Percentage transaction fee on value of entity acquired

1.00%

Consideration paid / received on assets acquired / disposed

1.00%

Affiliates of BMP | Transaction fee | Summit Materials, LLC

Related Party Transactions

Related party expense

$ 3,900,000

Percentage transaction fee on value of entity acquired

1.00%

Consideration paid / received on assets acquired / disposed

1.00%

Affiliates of Silverhawk Summit LP

Related Party Transactions

Related party expense

$ 400,000

Blackstone Advisory Partners LP | Follow on Public Offering | Common Class A

Related Party Transactions

Issuance of Shares (in shares)

1,681,875

Blackstone Advisory Partners LP | Issuance of notes | Term Loan, due 2022

Related Party Transactions

Notes issued to related party

$ 18,800,000

Blackstone Advisory Partners LP | Issuance of notes | 6 1/8% Senior Notes, due 2023

Related Party Transactions

Notes issued to related party

$ 22,500,000

$ 26,300,000

Blackstone Capital Partners V LP | Equity commitment financing

Related Party Transactions

Commitment fee paid

1,800,000

Blackstone Capital Partners V LP | Equity commitment financing | Davenport Assets

Related Party Transactions

Equity commitment financing

$ 90,000,000

Blackstone Capital Partners V LP | Equity commitment financing | Summit Materials, LLC

Related Party Transactions

Commitment fee paid

$ 1,800,000

Blackstone Capital Partners V LP | Equity commitment financing | Summit Materials, LLC | Davenport Assets

Related Party Transactions

Equity commitment financing

$ 90,000,000

Continental Cement

Related Party Transactions

Sales to related parties

1,400,000

$ 14,300,000

Continental Cement | Summit Materials, LLC

Related Party Transactions

Sales to related parties

$ 1,400,000

$ 14,300,000

Acquisition-Related Liabiliti96

Acquisition-Related Liabilities - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2016
Business Acquisition [Line Items]
Average term of noncompete agreements	5 years
Summit Materials, LLC
Business Acquisition [Line Items]
Average term of noncompete agreements	5 years
Minimum
Business Acquisition [Line Items]
Term of payment for deferred consideration	5 years
Minimum | Summit Materials, LLC
Business Acquisition [Line Items]
Term of payment for deferred consideration	5 years
Maximum
Business Acquisition [Line Items]
Term of payment for deferred consideration	20 years
Maximum | Summit Materials, LLC
Business Acquisition [Line Items]
Term of payment for deferred consideration	20 years

Acquisition-Related Liabiliti97

Acquisition-Related Liabilities - Remaining Payments Due under Noncompete and Deferred Consideration Agreements (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2016USD ($)
Business Combinations [Abstract]
2,017	$ 14,967
2,018	12,827
2,019	8,362
2,020	7,228
2,021	7,228
Thereafter	6,813
Total scheduled payments	57,425
Present value adjustments	(12,264)
Total noncompete obligations and deferred consideration	45,161
Summit Materials, LLC
Business Combinations [Abstract]
2,017	12,467
2,018	10,327
2,019	5,862
2,020	4,728
2,021	4,728
Thereafter	6,813
Total scheduled payments	44,925
Present value adjustments	(9,766)
Total noncompete obligations and deferred consideration	$ 35,159

Supplemental Cash Flow Inform98

Supplemental Cash Flow Information - Schedule of Supplemental Cash Flow Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Jan. 02, 2016	Dec. 27, 2014
Cash payments:
Interest	$ 82,540	$ 89,102	$ 64,097
Income taxes	2,645	1,685	$ 1,361
Non cash financing activities:
Purchase of noncontrolling interest in Continental Cement		(29,102)
Stock Dividend	(26,939)	$ (16,847)
Exchange of LP units to Common A Stock	$ 953,752

Leasing Arrangements - Addition

Leasing Arrangements - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Jan. 02, 2016	Dec. 27, 2014
Leases [Abstract]
Rent expense, including short-term rentals	$ 18.6	$ 12.1	$ 5.5
Royalty expense recorded in cost of revenue	15.6	12.6	9
Summit Materials, LLC
Leases [Abstract]
Rent expense, including short-term rentals	18.6	12.1	5.5
Royalty expense recorded in cost of revenue	$ 15.6	$ 12.6	$ 9

Leasing Arrangements - Minimum

Leasing Arrangements - Minimum Contractual Commitments Under Long-Term Operating Leases (Detail) $ in Thousands	Dec. 31, 2016USD ($)
Leases [Abstract]
2017, Operating Leases	$ 7,673
2018, Operating Leases	5,841
2019, Operating Leases	4,852
2020, Operating Leases	4,169
2021, Operating Leases	3,340
2017, Royalty Agreements	5,288
2018, Royalty Agreements	5,122
2019, Royalty Agreements	4,723
2020, Royalty Agreements	4,540
2021, Royalty Agreements	4,241
Summit Materials, LLC
Leases [Abstract]
2017, Operating Leases	7,673
2018, Operating Leases	5,841
2019, Operating Leases	4,852
2020, Operating Leases	4,169
2021, Operating Leases	3,340
2017, Royalty Agreements	5,288
2018, Royalty Agreements	5,122
2019, Royalty Agreements	4,723
2020, Royalty Agreements	4,540
2021, Royalty Agreements	$ 4,241

Redeemable Noncontrolling In101

Redeemable Noncontrolling Interest - Additional Information (Detail) $ in Thousands	12 Months Ended
	Jan. 02, 2016USD ($)installmentitemshares	Dec. 31, 2016	May 31, 2010shares
Redeemable Noncontrolling Interest
Cash consideration	$ 497,848
Continental Cement
Redeemable Noncontrolling Interest
Aggregate consideration for acquiring noncontrolling interests	64,100
Cash consideration	35,000
Consideration, Principal amount of note issued	$ 15,000
Redeemable noncontrolling interest percentage, approximately		30.00%
Continental Cement | Non interest bearing notes payable
Redeemable Noncontrolling Interest
Number of annual installments | installment	6
Annual installments amount of non-interest bearing notes payable	$ 2,500
Continental Cement | Common Class A
Redeemable Noncontrolling Interest
Consideration, shares issued | shares	1,029,183
Number of class units issued | shares	100
Economic interest of redeemable noncontrolling interest, approximately	70.00%
Continental Cement | Common Class B
Redeemable Noncontrolling Interest
Number of class units issued | shares			100,000,000
Economic interest of redeemable noncontrolling interest, approximately			30.00%
Summit Materials, LLC | Continental Cement
Redeemable Noncontrolling Interest
Aggregate consideration for acquiring noncontrolling interests	$ 64,100
Cash consideration	35,000
Redeemable noncontrolling interest percentage, approximately		30.00%
Summit Materials, LLC | Continental Cement | Non interest bearing notes payable
Redeemable Noncontrolling Interest
Consideration, Principal amount of note issued	$ 15,000
Number of annual installments | item	6
Annual installments amount of non-interest bearing notes payable	$ 2,500
Summit Materials, LLC | Continental Cement | Common Class A
Redeemable Noncontrolling Interest
Consideration, shares issued | shares	1,029,183
Number of class units issued | shares	100
Economic interest of redeemable noncontrolling interest, approximately	70.00%
Summit Materials, LLC | Continental Cement | Common Class B
Redeemable Noncontrolling Interest
Number of class units issued | shares			100,000,000
Economic interest of redeemable noncontrolling interest, approximately			30.00%

Employee Long Term Incentive102

Employee Long Term Incentive Plan - Additional Information	Aug. 19, 2016$ / shares	Mar. 10, 2015item	Dec. 31, 2016USD ($)item$ / sharesshares	Jan. 02, 2016USD ($)item$ / sharesshares	Dec. 27, 2014USD ($)$ / shares	Mar. 11, 2015$ / sharesshares
Reorganization
Number of Summit LP units purchased by Company, newly issued units (in shares)			45,124,528	18,675,000
Exchange of LP units to Common A Stock | $			$ 953,752,000
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions and Methodology [Abstract]
Risk-free interest rate (as a percent)			0.88%
Blackstone Management Partners L.L.C.
Reorganization
Number of Summit LP units purchased by Company, newly issued units (in shares)			45,124,528
Exchange of LP units to Common A Stock | $			$ 37,933,804
Leverage restoration options, time-vesting
Reorganization
Stock units vesting period			4 years
Percentage of options vesting on each anniversary			25.00%
Number of anniversaries over which options vest (in tranches) | item			4
Awards outstanding			190,020	411,727
Leverage restoration options, performance-vesting
Reorganization
Number of units, Vested (in shares)			187,879
Performance objective threshold waived (as a percent)	3
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions and Methodology [Abstract]
Exercise price (in dollars per share) | $ / shares	$ 18
Risk-free interest rate (as a percent)	1.55%
Dividend yield (as a percent)	0.00%
Volatility (as a percent)	48.00%
Expected term	9 years
Common Class A | Warrants issued to holders of Class C interests
Reorganization
Exercise price per share under the Omnibus Incentive Plan (in dollars per share) | $ / shares						$ 18
Common Class A | Leverage restoration options issued to holders of Class D interests
Reorganization
Exercise price per share under the Omnibus Incentive Plan (in dollars per share) | $ / shares						$ 18
General and administrative expenses
Reorganization
Modification charge recognized in general and administrative costs | $				$ 14,500,000
General and administrative expenses | Leverage restoration options, performance-vesting
Reorganization
Performance target expense | $			$ 37,300,000
2015 Omnibus Equity Incentive Plan
Reorganization
Options, Granted (in dollars per share) | $ / shares				$ 9
Awards granted			5,473,736
Stock option exercise price (in dollars per share) | $ / shares				$ 9
2015 Omnibus Equity Incentive Plan | Common Class A
Reorganization
Options, Granted (in dollars per share) | $ / shares			$ 18
Stock units vesting period			4 years
Percentage of options vesting on each anniversary			25.00%
Awards granted			240,000
Stock option exercise price (in dollars per share) | $ / shares			$ 18
2015 Omnibus Equity Incentive Plan | Common Class A | Leverage restoration options issued to holders of Class D interests
Reorganization
Number of warrants (in shares)						4,358,842
Stock options
Reorganization
Options, Granted (in dollars per share) | $ / shares			$ 8.90
Awards granted			2,822,259
Stock option exercise price (in dollars per share) | $ / shares			$ 8.90
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions and Methodology [Abstract]
Dividend yield (as a percent)			0.00%	0.00%	0.00%
Volatility (as a percent)			48.00%	50.00%	58.00%
Expected term			10 years
Restricted stock units
Reorganization
Weighted-average grant-date fair value | $ / shares			$ 17.52	$ 23.79
Stock units vesting period				4 years
Percentage of options vesting on each anniversary				25.00%
Number of anniversaries over which options vest (in tranches) | item				4
Number of units, Granted (in shares)			363,800	10,000
Awards outstanding			352,602	10,000
Number of units, Vested (in shares)			2,500
Summit Holdings LP
Reorganization
Number of classes of limited partnership interests | item		6
Number of years required for remaining units to be vested under vesting condition		4 years
Number of LP Units outstanding						69,007,297
Summit Holdings LP | Leverage restoration options, time-vesting
Reorganization
Number of LP Units outstanding						575,256
Summit Holdings LP | Leverage restoration options, performance-vesting
Reorganization
Number of LP Units outstanding						2,425,361
Summit Holdings LP | Class D-1
Reorganization
Units vesting period		5 years
Units vesting on first anniversary		20.00%
Units vesting monthly following the first anniversary		80.00%
Summit Holdings LP | Class D Units
Reorganization
Fair value of time-vesting units | $					$ 600,000
Weighted-average grant-date fair value | $ / shares					$ 1,368
Performance criteria, Achieving 1.75 times return on initial investment
Reorganization
Performance target ratio, return on initial investment (as a percent)			1.75

Employee Long Term Incentive103

Employee Long Term Incentive Plan - Summary of Information for Class D Unit Interests (Detail)	12 Months Ended
	Dec. 31, 2016item$ / sharesshares	Jan. 02, 2016item$ / sharesshares
Stock options
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Options, Beginning balance (in shares)	2,265,584
Options, Granted (in shares)	2,822,259
Options, Forfeited (in shares)	(73,046)
Options, Exercised (in shares)	(24,354)
Options, Ending balance (in shares)	4,990,443	2,265,584
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract]
Options, Beginning balance (in dollars per share) | $ / shares	$ 9
Options, Granted (in dollars per share) | $ / shares	8.90
Options, Forfeited (in dollars per share) | $ / shares	9.08
Options, Exercised (in dollars per share) | $ / shares	8.78
Options, Ending balance (in dollars per share) | $ / shares	$ 8.95	$ 9
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Awards granted	2,822,259
Restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Number of units, Beginning balance (in shares)	10,000
Number of units, Granted (in shares)	363,800	10,000
Number of units, Forfeited (in shares)	(18,698)
Number of units, Vested (in shares)	(2,500)
Number of units, Ending balance (in shares)	352,602	10,000
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Number of units, Beginning balance (in dollars per share) | $ / shares	$ 23.79
Number of units, Granted (in dollars per share) | $ / shares	17.52	$ 23.79
Number of units, Forfeited (in dollars per share) | $ / shares	18.65
Number of units, Vested (in dollars per share) | $ / shares	23.79
Number of units, Ending balance (in dollars per share) | $ / shares	$ 17.77	$ 23.79
Stock units vesting period		4 years
Percentage of options vesting on each anniversary		25.00%
Number of anniversaries over which options vest (in tranches) | item		4
Performance stock units
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Number of units, Granted (in shares)	130,691
Number of units, Ending balance (in shares)	130,691
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Number of units, Granted (in dollars per share) | $ / shares	$ 18.71
Number of units, Ending balance (in dollars per share) | $ / shares	$ 18.71
Warrants
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Number of units, Beginning balance (in shares)	160,333
Number of units, Ending balance (in shares)	160,333	160,333
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Number of units, Beginning balance (in dollars per share) | $ / shares	$ 18
Number of units, Ending balance (in dollars per share) | $ / shares	$ 18	$ 18
Other restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Number of units, Ending balance (in shares)	34,928
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Stock units vesting period	3 years
Percentage of options vesting on each anniversary	33.30%
Number of anniversaries over which options vest (in tranches) | item	3
Other restricted stock units | Minimum
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Number of units, Granted (in dollars per share) | $ / shares	$ 17.07
Other restricted stock units | Maximum
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Number of units, Granted (in dollars per share) | $ / shares	$ 21.63
2015 Omnibus Equity Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Options, Granted (in shares)	5,473,736
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract]
Options, Granted (in dollars per share) | $ / shares		$ 9
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Contractual term of awards	10 years
Awards granted	5,473,736
Number of shares authorized	13,500,000

Employee Long Term Incentive104

Employee Long Term Incentive Plan - Weighted Average Assumptions Used to Estimate the Fair Value of Grants (Detail)	12 Months Ended
	Dec. 31, 2016	Jan. 02, 2016	Dec. 27, 2014
Class D Units
Risk-free interest rate (as a percent)	0.88%
Stock options
Class D Units
Risk-free interest rate, Minimum	1.75%	1.68%	0.50%
Risk-free interest rate, Maximum	1.97%	1.92%	0.68%
Dividend yield (as a percent)	0.00%	0.00%	0.00%
Volatility (as a percent)	48.00%	50.00%	58.00%
Expected term	10 years
Stock options | Minimum
Class D Units
Expected term		7 years	3 years
Stock options | Maximum
Class D Units
Expected term		10 years	4 years
Performance stock units
Class D Units
Risk-free interest rate (as a percent)	0.88%
Dividend yield (as a percent)	0.00%
Volatility (as a percent)	37.00%
Expected term	3 years

Employee Long Term Incentive105

Employee Long Term Incentive Plan - Compensation and Intrinsic Value (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2016	Jan. 02, 2016	Dec. 27, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense	$ 49.9	$ 19.9	$ 2.2
Unrecognized compensation cost	$ 29.9
Weighted average contractual term, unrecognized compensation cost	2 years 9 months 18 days
Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average remaining contractual term	8 years 3 months 18 days
Weighted average strike price (in dollars per share)	$ 17.94
Intrinsic value, options outstanding	$ 29.2
Intrinsic value, options exercised	$ 0.1
Weighted average strike price, exercisable (in dollars per share)	$ 18.03
Weighed average remaining contractual term, exercisable	8 years 2 months 12 days
Exercisable (in shares)	1.1
Intrinsic value, exercisable stock options	$ 6.4
Restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average remaining contractual term	9 years 2 months 12 days
Intrinsic value, units outstanding	$ 8.4
Intrinsic value, vested	$ 0.1
Performance stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average remaining contractual term	9 years 2 months 12 days
Intrinsic value, units outstanding	$ 3.1

Segment Information - Financial

Segment Information - Financial Data (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2016USD ($)segment	Jan. 02, 2016USD ($)	Dec. 27, 2014USD ($)
Segment Information
Number of operating segments | segment	3
Total revenue	$ 1,626,063	$ 1,432,297	$ 1,204,231
Adjusted EBITDA	371,347	287,528	189,033
Interest expense	97,536	84,629	86,742
Depreciation, depletion and amortization	147,736	118,321	86,955
Accretion	1,564	1,402	871
IPO/Legacy modification costs	37,257	28,296
Loss on debt financings		71,631
Tax receivable agreement expense	14,938
Transaction costs	6,797	9,519	8,554
Management fees and expenses	(1,379)	1,046	4,933
Non-cash compensation	12,683	5,448	2,235
(Gain) loss on disposal and impairment of assets	3,805	(16,561)	8,735
Other	9,583	2,991	3,344
Income (loss) from operations before taxes	40,827	(19,194)	(13,336)
Total capital expenditures	153,483	88,950	76,162
Total depreciation, depletion, amortization and accretion	149,300	119,723	87,826
Total assets	$ 2,781,466	2,396,179	1,712,653
Summit Materials, LLC
Segment Information
Number of operating segments | segment	3
Total revenue	$ 1,626,063	1,432,297	1,204,231
Adjusted EBITDA	371,334	287,528	189,033
Interest expense	96,483	83,757	86,742
Depreciation, depletion and amortization	147,736	118,321	86,955
Accretion	1,564	1,402	871
IPO/Legacy modification costs	37,257	28,296
Loss on debt financings		71,631
Transaction costs	6,797	9,519	8,554
Management fees and expenses	(1,379)	1,046	4,933
Non-cash compensation	12,683	5,448	2,235
(Gain) loss on disposal and impairment of assets	3,805	(16,561)	8,735
Other	9,583	2,991	3,344
Income (loss) from operations before taxes	56,805	(18,322)	(13,336)
Total capital expenditures	153,483	88,950	76,162
Total depreciation, depletion, amortization and accretion	149,300	119,723	87,826
Total assets	2,776,420	2,395,162	1,712,653
Operating segment
Segment Information
Total capital expenditures	148,235	83,315	71,629
Total depreciation, depletion, amortization and accretion	146,891	117,408	86,358
Total assets	2,641,816	2,210,607	1,689,428
Operating segment | Summit Materials, LLC
Segment Information
Total revenue	1,626,063	1,432,297	1,204,231
Adjusted EBITDA	126,007	92,303	73,822
Total capital expenditures	148,235	83,315	71,629
Total depreciation, depletion, amortization and accretion	146,891	117,408	86,358
Total assets	2,641,816	2,210,607	1,689,428
Operating segment | West
Segment Information
Total revenue	813,682	804,503	665,716
Adjusted EBITDA	167,434	150,764	102,272
Total capital expenditures	77,335	39,896	31,968
Total depreciation, depletion, amortization and accretion	65,345	53,727	33,271
Total assets	902,763	821,479	771,234
Operating segment | West | Summit Materials, LLC
Segment Information
Total revenue	813,682	804,503	665,716
Adjusted EBITDA	167,434	150,764	102,272
Total capital expenditures	77,335	39,896	31,968
Total depreciation, depletion, amortization and accretion	65,345	53,727	33,271
Total assets	902,763	821,479	771,234
Operating segment | East
Segment Information
Total revenue	531,294	432,310	432,942
Adjusted EBITDA	126,007	92,303	73,822
Total capital expenditures	45,492	26,268	23,702
Total depreciation, depletion, amortization and accretion	51,540	38,923	38,035
Total assets	870,613	545,187	553,843
Operating segment | East | Summit Materials, LLC
Segment Information
Total revenue	531,294	432,310	432,942
Total capital expenditures	45,492	26,268	23,702
Total depreciation, depletion, amortization and accretion	51,540	38,923	38,035
Total assets	870,613	545,187	553,843
Operating segment | Cement
Segment Information
Total revenue	281,087	195,484	105,573
Adjusted EBITDA	112,991	74,845	35,133
Total capital expenditures	25,408	17,151	15,959
Total depreciation, depletion, amortization and accretion	30,006	24,758	15,052
Total assets	868,440	843,941	364,351
Operating segment | Cement | Summit Materials, LLC
Segment Information
Total revenue	281,087	195,484	105,573
Adjusted EBITDA	112,991	74,845	35,133
Total capital expenditures	25,408	17,151	15,959
Total depreciation, depletion, amortization and accretion	30,006	24,758	15,052
Total assets	868,440	843,941	364,351
Corporate and other
Segment Information
Adjusted EBITDA	(35,085)	(30,384)	(22,194)
Total capital expenditures	5,248	5,635	4,533
Total depreciation, depletion, amortization and accretion	2,409	2,315	1,468
Total assets	139,650	185,572	23,225
Corporate and other | Summit Materials, LLC
Segment Information
Adjusted EBITDA	(35,098)	(30,384)	(22,194)
Total capital expenditures	5,248	5,635	4,533
Total depreciation, depletion, amortization and accretion	2,409	2,315	1,468
Total assets	$ 134,604	$ 184,555	$ 23,225

Segment Information - By Produc

Segment Information - By Product (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Jan. 02, 2016	Dec. 27, 2014
Revenue by product
Total revenue	$ 1,626,063	$ 1,432,297	$ 1,204,231
Aggregates
Revenue by product
Total revenue	264,609	219,040	161,496
Cement
Revenue by product
Total revenue	250,349	167,696	89,911
Ready-mixed concrete
Revenue by product
Total revenue	395,917	350,262	274,220
Asphalt
Revenue by product
Total revenue	239,419	252,031	237,510
Paving and related services
Revenue by product
Total revenue	304,041	295,995	326,378
Other
Revenue by product
Total revenue	171,728	147,273	114,716
Summit Materials, LLC
Revenue by product
Total revenue	1,626,063	1,432,297	1,204,231
Summit Materials, LLC | Aggregates
Revenue by product
Total revenue	264,609	219,040	161,496
Summit Materials, LLC | Cement
Revenue by product
Total revenue	250,349	167,696	89,911
Summit Materials, LLC | Ready-mixed concrete
Revenue by product
Total revenue	395,917	350,262	274,220
Summit Materials, LLC | Asphalt
Revenue by product
Total revenue	239,419	252,031	237,510
Summit Materials, LLC | Paving and related services
Revenue by product
Total revenue	304,041	295,995	326,378
Summit Materials, LLC | Other
Revenue by product
Total revenue	$ 171,728	$ 147,273	$ 114,716

Guarantor and Non-Guarantor Fin

Guarantor and Non-Guarantor Financial Information - Schedule of Condensed Consolidating Balance Sheets (Details) - USD ($)	Dec. 31, 2016	Jan. 02, 2016	Dec. 27, 2014	Dec. 28, 2013
Current assets:
Cash and cash equivalents	$ 143,392,000	$ 186,405,000	$ 13,215,000	$ 18,184,000
Accounts receivable, net	162,377,000	145,544,000
Cost and estimated earnings in excess of billings	7,450,000	5,690,000
Inventories	157,679,000	130,082,000
Other current assets	12,800,000	4,807,000
Total current assets	483,698,000	472,528,000
Property, plant and equipment, net	1,446,452,000	1,269,006,000
Goodwill	782,212,000	596,397,000	419,270,000
Intangible assets, net	17,989,000	15,005,000
Other assets	51,115,000	43,243,000
Total assets	2,781,466,000	2,396,179,000	1,712,653,000
Current liabilities:
Current portion of debt	6,500,000	6,500,000
Current portion of acquisition-related liabilities	24,162,000	20,584,000
Accounts payable	81,565,000	81,397,000
Accrued expenses	111,605,000	92,942,000
Billings in excess of costs and estimated earnings	15,456,000	13,081,000
Total current liabilities	239,288,000	214,504,000
Long-term debt	1,514,456,000	1,273,652,000
Acquisition-related liabilities	32,664,000	39,977,000
Other noncurrent liabilities	135,019,000	100,186,000
Total liabilities	1,921,427,000	1,628,319,000
Total liabilities and stockholders' equity / member's interest	2,781,466,000	2,396,179,000
Summit Materials, LLC
Current assets:
Cash and cash equivalents	142,672,000	185,388,000	13,215,000	14,917,000
Accounts receivable, net	162,377,000	145,544,000
Cost and estimated earnings in excess of billings	7,450,000	5,690,000
Inventories	157,679,000	130,082,000
Other current assets	12,800,000	4,807,000
Total current assets	482,978,000	471,511,000
Property, plant and equipment, net	1,446,452,000	1,269,006,000
Goodwill	782,212,000	596,397,000	419,270,000
Intangible assets, net	17,989,000	15,005,000
Other assets	46,789,000	43,243,000
Total assets	2,776,420,000	2,395,162,000	1,712,653,000
Current liabilities:
Current portion of debt	6,500,000	6,500,000
Current portion of acquisition-related liabilities	21,663,000	18,084,000
Accounts payable	81,610,000	81,397,000
Accrued expenses	110,473,000	92,942,000
Billings in excess of costs and estimated earnings	15,456,000	13,081,000
Total current liabilities	235,702,000	212,004,000
Long-term debt	1,514,456,000	1,273,652,000
Acquisition-related liabilities	25,161,000	31,028,000
Other noncurrent liabilities	124,708,000	100,186,000
Total liabilities	1,900,027,000	1,616,870,000
Total member's interest	876,393,000	778,292,000
Total liabilities and stockholders' equity / member's interest	2,776,420,000	2,395,162,000
Summit Materials, LLC | Eliminations
Current assets:
Cash and cash equivalents	(10,666,000)	(11,600,000)	(7,112,000)	(2,540,000)
Accounts receivable, net	(102,000)	(54,000)
Intercompany receivables	(843,434,000)	(687,383,000)
Total current assets	(854,202,000)	(699,037,000)
Other assets	(3,283,133,000)	(1,930,926,000)
Total assets	(4,137,335,000)	(2,629,963,000)
Current liabilities:
Accounts payable	(102,000)	(54,000)
Accrued expenses	(10,666,000)	(11,600,000)
Intercompany payables	(843,434,000)	(687,383,000)
Total current liabilities	(854,202,000)	(699,037,000)
Other noncurrent liabilities	(165,242,000)	(155,293,000)
Total liabilities	(1,019,444,000)	(854,330,000)
Total member's interest	(3,117,891,000)	(1,775,633,000)
Total liabilities and stockholders' equity / member's interest	(4,137,335,000)	(2,629,963,000)
Summit Materials, LLC | Issuers
Current assets:
Cash and cash equivalents	133,862,000	180,712,000	10,837,000	10,375,000
Accounts receivable, net		1,000
Intercompany receivables	521,658,000	562,311,000
Other current assets	1,259,000	764,000
Total current assets	656,779,000	743,788,000
Property, plant and equipment, net	7,033,000	10,355,000
Other assets	3,202,706,000	1,840,889,000
Total assets	3,866,518,000	2,595,032,000
Current liabilities:
Current portion of debt	6,500,000	6,500,000
Current portion of acquisition-related liabilities	1,000,000	1,400,000
Accounts payable	1,497,000	2,138,000
Accrued expenses	46,460,000	40,437,000
Intercompany payables	509,503,000	122,174,000
Total current liabilities	564,960,000	172,649,000
Long-term debt	1,514,456,000	1,273,652,000
Other noncurrent liabilities	2,395,000	1,292,000
Total liabilities	2,081,811,000	1,447,593,000
Total member's interest	1,784,707,000	1,147,439,000
Total liabilities and stockholders' equity / member's interest	3,866,518,000	2,595,032,000
Summit Materials, LLC | Guarantors
Current assets:
Cash and cash equivalents	4,820,000	4,068,000	695,000	3,442,000
Accounts receivable, net	155,389,000	136,916,000
Intercompany receivables	321,776,000	114,402,000
Cost and estimated earnings in excess of billings	6,830,000	5,389,000
Inventories	153,374,000	126,553,000
Other current assets	11,012,000	3,306,000
Total current assets	653,201,000	390,634,000
Property, plant and equipment, net	1,418,902,000	1,232,340,000
Goodwill	735,490,000	550,028,000
Intangible assets, net	17,989,000	13,797,000
Other assets	125,270,000	130,992,000
Total assets	2,950,852,000	2,317,791,000
Current liabilities:
Current portion of acquisition-related liabilities	20,663,000	16,684,000
Accounts payable	76,886,000	74,111,000
Accrued expenses	73,807,000	62,217,000
Intercompany payables	327,405,000	562,537,000
Billings in excess of costs and estimated earnings	15,242,000	12,980,000
Total current liabilities	514,003,000	728,529,000
Acquisition-related liabilities	25,161,000	31,028,000
Other noncurrent liabilities	231,199,000	197,484,000
Total liabilities	770,363,000	957,041,000
Total member's interest	2,180,489,000	1,360,750,000
Total liabilities and stockholders' equity / member's interest	2,950,852,000	2,317,791,000
Summit Materials, LLC | Non Guarantors
Current assets:
Cash and cash equivalents	14,656,000	12,208,000	8,793,000	3,631,000
Accounts receivable, net	7,090,000	8,681,000
Intercompany receivables		10,670,000
Cost and estimated earnings in excess of billings	620,000	301,000
Inventories	4,305,000	3,529,000
Other current assets	529,000	737,000
Total current assets	27,200,000	36,126,000
Property, plant and equipment, net	20,517,000	26,311,000
Goodwill	46,722,000	46,369,000
Intangible assets, net		1,208,000
Other assets	1,946,000	2,288,000
Total assets	96,385,000	112,302,000
Current liabilities:
Accounts payable	3,329,000	5,202,000
Accrued expenses	872,000	1,888,000
Intercompany payables	6,526,000	2,672,000
Billings in excess of costs and estimated earnings	214,000	101,000
Total current liabilities	10,941,000	9,863,000
Other noncurrent liabilities	56,356,000	56,703,000
Total liabilities	67,297,000	66,566,000
Total member's interest	29,088,000	45,736,000
Total liabilities and stockholders' equity / member's interest	$ 96,385,000	$ 112,302,000
Summit Materials, LLC | Non Wholly-owned Guarantors
Current assets:
Cash and cash equivalents			$ 2,000	$ 9,000

Guarantor and Non-Guarantor 109

Guarantor and Non-Guarantor Financial Information - Schedule of Condensed Consolidating Statements of Operations and Comprehensive Loss (Details) - USD ($) $ in Thousands	2 Months Ended	3 Months Ended								10 Months Ended	12 Months Ended
	Mar. 11, 2015	Dec. 31, 2016	Oct. 01, 2016	Jul. 02, 2016	Apr. 02, 2016	Jan. 02, 2016	Sep. 26, 2015	Jun. 27, 2015	Mar. 28, 2015	Jan. 02, 2016	Dec. 31, 2016	Jan. 02, 2016	Dec. 27, 2014
Condensed Consolidating Statements of Operations
Revenue											$ 1,626,063	$ 1,432,297	$ 1,204,231
Cost of revenue (excluding items shown separately below)											1,072,070	990,645	887,160
Depreciation, depletion, amortization and accretion											149,300	119,723	87,826
Operating income (loss)		$ 48,604	$ 88,253	$ 46,732	$ (29,555)	$ 67,990	$ 83,357	$ 42,300	$ (59,006)		154,034	134,641	69,959
Other (income) loss, net											733	(2,425)	(3,447)
Interest expense											97,536	84,629	86,742
Income (loss) from operations before taxes											40,827	(19,194)	(13,336)
Income tax (benefit) expense											(5,299)	(18,263)	(6,983)
Income (loss) from continuing operations		6,049	61,106	21,505	(42,534)	45,816	33,815	(725)	(79,837)		46,126	(931)	(6,353)
Income from discontinued operations												(2,415)	(71)
Net income (loss)	$ (41,415)	6,049	61,106	21,505	(42,534)	47,416	33,872	33	(79,837)	$ 44,789	46,126	1,484	(6,282)
Net income (loss) attributable to member of Summit Materials, LLC		(290)	44,820	13,371	(21,118)	23,363	14,711	(205)	(10,151)		36,783	27,718
Comprehensive (loss) income attributable to member of Summit Materials, LLC											37,329	24,923
Summit Materials, LLC
Condensed Consolidating Statements of Operations
Revenue											1,626,063	1,432,297	1,204,231
Cost of revenue (excluding items shown separately below)											1,072,070	990,645	887,160
General and administrative expenses											250,659	187,288	159,286
Depreciation, depletion, amortization and accretion											149,300	119,723	87,826
Operating income (loss)		48,604	88,253	46,732	(29,555)	67,990	83,357	42,300	(59,006)		154,034	134,641	69,959
Other (income) loss, net												69,206
Other (income) loss, net											746	(2,425)	(3,447)
Interest expense											96,483	83,757	86,742
Income (loss) from operations before taxes											56,805	(18,322)	(13,336)
Income tax (benefit) expense											(5,282)	(18,263)	(6,983)
Income (loss) from continuing operations		21,211	61,360	21,759	(42,243)	46,106	34,106	(434)	(79,837)		62,087	(59)	(6,353)
Income from discontinued operations												(2,415)	(71)
Net income (loss)		$ 21,211	$ 61,360	$ 21,759	$ (42,243)	$ 47,706	$ 34,163	$ 324	$ (79,837)		62,087	2,356	(6,282)
Net income (loss) attributable to noncontrolling interest											16	(1,826)	2,495
Net income (loss) attributable to member of Summit Materials, LLC											62,071	4,182	(8,777)
Comprehensive (loss) income attributable to member of Summit Materials, LLC											63,093	(8,738)	(18,278)
Summit Materials, LLC | Eliminations
Condensed Consolidating Statements of Operations
Revenue											(7,859)	(32,685)	(27,933)
Cost of revenue (excluding items shown separately below)											(7,859)	(32,685)	(27,933)
Other (income) loss, net												166,632
Other (income) loss, net											238,874		71,514
Interest expense													(9,113)
Income (loss) from operations before taxes											(238,874)	(166,632)	(62,401)
Income (loss) from continuing operations											(238,874)	(166,632)	(62,401)
Net income (loss)											(238,874)	(166,632)	(62,401)
Net income (loss) attributable to noncontrolling interest											16	(1,826)	2,495
Net income (loss) attributable to member of Summit Materials, LLC											(238,890)	(164,806)	(64,896)
Comprehensive (loss) income attributable to member of Summit Materials, LLC											(237,868)	(151,886)	(53,815)
Summit Materials, LLC | Issuers
Condensed Consolidating Statements of Operations
General and administrative expenses											91,533	73,555	30,736
Depreciation, depletion, amortization and accretion											2,410	2,316	1,468
Operating income (loss)											(93,943)	(75,871)	(32,204)
Other (income) loss, net												(107,275)
Other (income) loss, net											(239,082)		(53,827)
Interest expense											83,068	27,222	31,827
Income (loss) from operations before taxes											62,071	4,182	(10,204)
Income tax (benefit) expense													(1,427)
Income (loss) from continuing operations											62,071	4,182	(8,777)
Net income (loss)											62,071	4,182	(8,777)
Net income (loss) attributable to member of Summit Materials, LLC											62,071	4,182	(8,777)
Comprehensive (loss) income attributable to member of Summit Materials, LLC											63,093	(8,738)	(18,278)
Summit Materials, LLC | Non Wholly-owned Guarantors
Condensed Consolidating Statements of Operations
Revenue													94,402
Cost of revenue (excluding items shown separately below)													67,951
General and administrative expenses													6,763
Depreciation, depletion, amortization and accretion													14,500
Operating income (loss)													5,188
Other (income) loss, net													(14,444)
Interest expense													11,608
Income (loss) from operations before taxes													8,024
Income (loss) from continuing operations													8,024
Net income (loss)													8,024
Net income (loss) attributable to member of Summit Materials, LLC													8,024
Comprehensive (loss) income attributable to member of Summit Materials, LLC													2,759
Summit Materials, LLC | Guarantors
Condensed Consolidating Statements of Operations
Revenue											1,586,858	1,364,622	1,065,590
Cost of revenue (excluding items shown separately below)											1,047,398	958,527	796,078
General and administrative expenses											152,752	107,282	119,250
Depreciation, depletion, amortization and accretion											142,773	112,166	70,116
Operating income (loss)											243,935	186,647	80,146
Other (income) loss, net												9,555
Other (income) loss, net											1,280		(6,687)
Interest expense											9,956	52,970	51,248
Income (loss) from operations before taxes											232,699	124,122	35,585
Income tax (benefit) expense											(5,551)	(18,664)	(5,766)
Income (loss) from continuing operations											238,250	142,786	41,351
Income from discontinued operations												(2,415)	(71)
Net income (loss)											238,250	145,201	41,422
Net income (loss) attributable to member of Summit Materials, LLC											238,250	145,201	41,422
Comprehensive (loss) income attributable to member of Summit Materials, LLC											239,353	146,380	41,422
Summit Materials, LLC | Non Guarantors
Condensed Consolidating Statements of Operations
Revenue											47,064	100,360	72,172
Cost of revenue (excluding items shown separately below)											32,531	64,803	51,064
General and administrative expenses											6,374	6,451	2,537
Depreciation, depletion, amortization and accretion											4,117	5,241	1,742
Operating income (loss)											4,042	23,865	16,829
Other (income) loss, net												294
Other (income) loss, net											(326)		(3)
Interest expense											3,459	3,565	1,172
Income (loss) from operations before taxes											909	20,006	15,660
Income tax (benefit) expense											269	401	210
Income (loss) from continuing operations											640	19,605	15,450
Net income (loss)											640	19,605	15,450
Net income (loss) attributable to member of Summit Materials, LLC											640	19,605	15,450
Comprehensive (loss) income attributable to member of Summit Materials, LLC											$ (1,485)	$ 5,506	$ 9,634

Guarantor and Non-Guarantor 110

Guarantor and Non-Guarantor Financial Information - Schedule of Condensed Consolidating Statements of Cash Flows (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Jan. 02, 2016	Dec. 27, 2014
Condensed Consolidating Statements of Operations
Net cash (used in) provided by operating activities	$ 244,863	$ 98,203	$ 79,238
Cash flow from investing activities:
Acquisitions, net of cash acquired	(336,958)	(510,017)	(397,854)
Purchase of property, plant and equipment	(153,483)	(88,950)	(76,162)
Proceeds from the sale of property, plant, and equipment	16,868	13,110	13,366
Other	2,921	1,510	(630)
Net cash used for investing activities	(470,652)	(584,347)	(461,280)
Cash flow from financing activities:
Capital issuance costs	(136)	(61,609)
Net proceeds from debt issuance	354,000	1,748,875	762,250
Payments on long-term debt	(120,702)	(1,505,486)	(389,270)
Payments on acquisition-related liabilities	(32,040)	(18,056)	(10,935)
Financing costs	(5,801)	(14,246)	(9,085)
Distributions from partnership	(13,034)	(28,736)
Other	420	(1)	(88)
Net cash provided by financing activities	182,707	660,337	377,222
Impact of cash on foreign currency	69	(1,003)	(149)
Net increase (decrease) in cash	(43,013)	173,190	(4,969)
Cash and cash equivalents-beginning of period	186,405	13,215	18,184
Cash and cash equivalents-end of period	143,392	186,405	13,215
Summit Materials, LLC
Condensed Consolidating Statements of Operations
Net cash (used in) provided by operating activities	244,877	98,203	79,238
Cash flow from investing activities:
Acquisitions, net of cash acquired	(336,958)	(510,017)	(397,854)
Purchase of property, plant and equipment	(153,483)	(88,950)	(76,162)
Proceeds from the sale of property, plant, and equipment	16,868	13,110	13,366
Other	2,921	1,510	(630)
Net cash used for investing activities	(470,652)	(584,347)	(461,280)
Cash flow from financing activities:
Proceeds from investment by member	27,377	507,766	27,617
Capital issuance costs	(136)	(12,930)
Net proceeds from debt issuance	354,000	1,748,875	762,250
Payments on long-term debt	(120,702)	(1,505,486)	(389,270)
Payments on acquisition-related liabilities	(29,540)	(18,056)	(10,935)
Financing costs	(5,801)	(14,246)	(9,085)
Distributions from partnership	(42,192)	(46,603)
Other	(16)		(88)
Net cash provided by financing activities	182,990	659,320	380,489
Impact of cash on foreign currency	69	(1,003)	(149)
Net increase (decrease) in cash	(42,716)	172,173	(1,702)
Cash and cash equivalents-beginning of period	185,388	13,215	14,917
Cash and cash equivalents-end of period	142,672	185,388	13,215
Summit Materials, LLC | Eliminations
Condensed Consolidating Statements of Operations
Net cash (used in) provided by operating activities		(167)	(2,000)
Cash flow from investing activities:
Other			1,354
Net cash used for investing activities			1,354
Cash flow from financing activities:
Proceeds from investment by member			(1,354)
Loans received from and payments made on loans from other Summit Companies	934	(5,544)	(4,572)
Payments on long-term debt		1,056
Other		167	2,000
Net cash provided by financing activities	934	(4,321)	(3,926)
Net increase (decrease) in cash	934	(4,488)	(4,572)
Cash and cash equivalents-beginning of period	(11,600)	(7,112)	(2,540)
Cash and cash equivalents-end of period	(10,666)	(11,600)	(7,112)
Summit Materials, LLC | Issuers
Condensed Consolidating Statements of Operations
Net cash (used in) provided by operating activities	(132,328)	(276,104)	(40,964)
Cash flow from investing activities:
Acquisitions, net of cash acquired	(42,844)		(181,754)
Purchase of property, plant and equipment	(5,247)	(5,636)	(4,534)
Net cash used for investing activities	(48,091)	(5,636)	(186,288)
Cash flow from financing activities:
Proceeds from investment by member	(502,140)	(155,060)	27,617
Capital issuance costs	(136)	(12,930)
Net proceeds from debt issuance	354,000	1,748,875	762,250
Loans received from and payments made on loans from other Summit Companies	440,738	(208,459)	(170,915)
Payments on long-term debt	(110,500)	(859,796)	(380,065)
Payments on acquisition-related liabilities	(400)	(166)	(2,000)
Financing costs	(5,801)	(14,246)	(9,085)
Distributions from partnership	(42,192)	(46,603)
Other			(88)
Net cash provided by financing activities	133,569	451,615	227,714
Net increase (decrease) in cash	(46,850)	169,875	462
Cash and cash equivalents-beginning of period	180,712	10,837	10,375
Cash and cash equivalents-end of period	133,862	180,712	10,837
Summit Materials, LLC | Non Wholly-owned Guarantors
Condensed Consolidating Statements of Operations
Net cash (used in) provided by operating activities			11,776
Cash flow from investing activities:
Purchase of property, plant and equipment			(14,941)
Other			(1,387)
Net cash used for investing activities			(16,328)
Cash flow from financing activities:
Loans received from and payments made on loans from other Summit Companies			5,338
Payments on long-term debt			(793)
Net cash provided by financing activities			4,545
Net increase (decrease) in cash			(7)
Cash and cash equivalents-beginning of period		2	9
Cash and cash equivalents-end of period			2
Summit Materials, LLC | Guarantors
Condensed Consolidating Statements of Operations
Net cash (used in) provided by operating activities	373,588	356,187	102,219
Cash flow from investing activities:
Acquisitions, net of cash acquired	(294,114)	(510,017)	(216,100)
Purchase of property, plant and equipment	(146,336)	(81,980)	(55,222)
Proceeds from the sale of property, plant, and equipment	16,606	12,945	13,134
Other	2,921	1,510	(597)
Net cash used for investing activities	(420,923)	(577,542)	(258,785)
Cash flow from financing activities:
Proceeds from investment by member	529,517	662,826
Loans received from and payments made on loans from other Summit Companies	(442,072)	226,703	173,166
Payments on long-term debt	(10,202)	(646,746)	(8,412)
Payments on acquisition-related liabilities	(29,140)	(17,890)	(8,935)
Other	(16)	(167)	(2,000)
Net cash provided by financing activities	48,087	224,726	153,819
Net increase (decrease) in cash	752	3,371	(2,747)
Cash and cash equivalents-beginning of period	4,068	695	3,442
Cash and cash equivalents-end of period	4,820	4,068	695
Summit Materials, LLC | Non Guarantors
Condensed Consolidating Statements of Operations
Net cash (used in) provided by operating activities	3,617	18,287	8,207
Cash flow from investing activities:
Purchase of property, plant and equipment	(1,900)	(1,334)	(1,465)
Proceeds from the sale of property, plant, and equipment	262	165	232
Net cash used for investing activities	(1,638)	(1,169)	(1,233)
Cash flow from financing activities:
Proceeds from investment by member			1,354
Loans received from and payments made on loans from other Summit Companies	400	(12,700)	(3,017)
Net cash provided by financing activities	400	(12,700)	(1,663)
Impact of cash on foreign currency	69	(1,003)	(149)
Net increase (decrease) in cash	2,448	3,415	5,162
Cash and cash equivalents-beginning of period	12,208	8,793	3,631
Cash and cash equivalents-end of period	$ 14,656	$ 12,208	$ 8,793

Supplementary Data (Unaudite111

Supplementary Data (Unaudited) - Supplemental Financial Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	2 Months Ended	3 Months Ended								10 Months Ended	12 Months Ended
	Mar. 11, 2015	Dec. 31, 2016	Oct. 01, 2016	Jul. 02, 2016	Apr. 02, 2016	Jan. 02, 2016	Sep. 26, 2015	Jun. 27, 2015	Mar. 28, 2015	Jan. 02, 2016	Dec. 31, 2016	Jan. 02, 2016	Dec. 27, 2014
Condensed Income Statements, Captions [Line Items]
Net revenue		$ 387,389	$ 480,210	$ 412,636	$ 208,039	$ 359,532	$ 426,286	$ 329,009	$ 175,139		$ 1,488,274	$ 1,289,966	$ 1,070,605
Operating income (loss)		48,604	88,253	46,732	(29,555)	67,990	83,357	42,300	(59,006)		154,034	134,641	69,959
Income (loss) from continuing operations		6,049	61,106	21,505	(42,534)	45,816	33,815	(725)	(79,837)		46,126	(931)	(6,353)
Net income (loss)	$ (41,415)	6,049	61,106	21,505	(42,534)	47,416	33,872	33	(79,837)	$ 44,789	46,126	1,484	(6,282)
Net income (loss) attributable to Summit Inc.		$ (290)	$ 44,820	$ 13,371	$ (21,118)	$ 23,363	$ 14,711	$ (205)	$ (10,151)		$ 36,783	$ 27,718
Basic earnings per share attributable to Summit Inc.		$ 0	$ 0.60	$ 0.21	$ (0.42)	$ 0.46	$ 0.37	$ (0.01)	$ (0.36)
Diluted earnings per share attributable to Summit Inc.		$ 0	$ 0.60	$ 0.21	$ (0.42)	$ 0.46	$ 0.37	$ (0.01)	$ (0.36)
Retroactive application of common stock issued as dividends (in shares)											1,135,962	735,108
Summit Materials, LLC
Condensed Income Statements, Captions [Line Items]
Net revenue		$ 387,389	$ 480,210	$ 412,636	$ 208,039	$ 359,532	$ 426,286	$ 329,009	$ 175,139		$ 1,488,274	$ 1,289,966	1,070,605
Operating income (loss)		48,604	88,253	46,732	(29,555)	67,990	83,357	42,300	(59,006)		154,034	134,641	69,959
Income (loss) from continuing operations		21,211	61,360	21,759	(42,243)	46,106	34,106	(434)	(79,837)		62,087	(59)	(6,353)
Net income (loss)		$ 21,211	$ 61,360	$ 21,759	$ (42,243)	$ 47,706	$ 34,163	$ 324	$ (79,837)		62,087	2,356	(6,282)
Net income (loss) attributable to Summit Inc.											$ 62,071	$ 4,182	$ (8,777)

Subsequent Events (Details)

Subsequent Events (Details) $ / shares in Units, $ in Thousands	Jan. 19, 2017	Jan. 10, 2017USD ($)item$ / sharesshares	Jan. 02, 2016USD ($)	Dec. 31, 2016USD ($)
Subsequent Events
Proceeds from sale of common stock, net of underwriting discounts			$ 1,037,444
Outstanding principal amount				$ 1,540,250
Term Loan, due 2022
Subsequent Events
Outstanding principal amount			646,800	640,300
Forecast
Subsequent Events
Number of materials-based companies to be acquired | item		2
Combined purchase price		$ 110,000
Subsequent Event | Term Loan, due 2022
Subsequent Events
Prepayment premium on repricing events occuring within a specified time period (as a percent)	1.00%
Time period for repricing events	6 months
Summit Materials, LLC
Subsequent Events
Outstanding principal amount				1,540,250
Summit Materials, LLC | Term Loan, due 2022
Subsequent Events
Outstanding principal amount			$ 646,800	$ 640,300
Summit Materials, LLC | Forecast
Subsequent Events
Number of materials-based companies to be acquired | item		2
Combined purchase price		$ 110,000
Summit Materials, LLC | Subsequent Event | Term Loan, due 2022
Subsequent Events
Prepayment premium on repricing events occuring within a specified time period (as a percent)	1.00%
Time period for repricing events	6 months
Common Class A | Subsequent Event
Subsequent Events
Proceeds from sale of common stock, net of underwriting discounts		$ 237,600
Common stock issued (in shares) | shares		10,000,000
Offering price (in dollars per share) | $ / shares		$ 24.05
Common Class A | Summit Materials, LLC | Subsequent Event
Subsequent Events
Proceeds from sale of common stock, net of underwriting discounts		$ 237,600
Common stock issued (in shares) | shares		10,000,000
Offering price (in dollars per share) | $ / shares		$ 24.05