Summit Materials (SUM) 10-Q 8 May 19 2019 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Mar. 30, 2019	May 02, 2019
Document Information [Line Items]
Entity Registrant Name	Summit Materials, Inc.
Entity Central Index Key	0001621563
Document Type	10-Q
Document Period End Date	Mar. 30, 2019
Amendment Flag	false
Current Fiscal Year End Date	--03-30
Entity Filer Category	Large Accelerated Filer
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q1
Common Class A
Document Information [Line Items]
Entity common stock, shares outstanding (in shares)		112,067,531
Class B Common Stock
Document Information [Line Items]
Entity common stock, shares outstanding (in shares)		99
Summit Materials, LLC
Document Information [Line Items]
Entity Registrant Name	Summit Materials, LLC
Entity Central Index Key	0001571371
Document Type	10-Q
Document Period End Date	Mar. 30, 2019
Amendment Flag	false
Current Fiscal Year End Date	--03-30
Entity Filer Category	Non-accelerated Filer
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q1

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 30, 2019	Dec. 29, 2018
Current assets:
Cash and cash equivalents	$ 64,837	$ 128,508
Accounts receivable, net	195,411	214,518
Costs and estimated earnings in excess of billings	17,079	18,602
Inventories	214,038	213,851
Other current assets	19,245	16,061
Total current assets	510,610	591,540
Property, plant and equipment, less accumulated depreciation, depletion and amortization (March 30, 2019 - $837,896 and December 29, 2018 - $794,251)	1,799,941	1,780,132
Goodwill	1,195,262	1,192,028
Intangible assets, less accumulated amortization (March 30, 2019 - $8,656 and December 29, 2018 - $8,247)	18,051	18,460
Deferred tax assets, less valuation allowance (March 30, 2019 - $21,859 and December 29, 2018 - $19,366)	253,104	225,397
Operating lease right-of-use assets	34,403
Other assets	49,990	50,084
Total assets	3,861,361	3,857,641
Current liabilities:
Current portion of debt	4,765	6,354
Current portion of acquisition-related liabilities	37,422	34,270
Accounts payable	101,843	107,702
Accrued expenses	96,476	100,491
Current operating lease liabilities	8,098
Billings in excess of costs and estimated earnings	10,656	11,840
Total current liabilities	259,260	260,657
Long-term debt	1,855,346	1,807,502
Acquisition-related liabilities	38,908	49,468
Tax receivable agreement liability	309,733	309,674
Noncurrent operating lease liabilities	27,200
Other noncurrent liabilities	92,439	88,195
Total liabilities	2,582,886	2,515,496
Commitments and contingencies (see note 12)
Stockholders’ equity:
Additional paid-in capital	1,200,503	1,194,204
Accumulated earnings	60,967	129,739
Accumulated other comprehensive income	4,265	2,681
Stockholders’ equity	1,266,856	1,327,741
Noncontrolling interest in Summit Holdings	11,619	14,404
Total stockholders’ equity	1,278,475	1,342,145
Total liabilities and stockholders’ equity	3,861,361	3,857,641
Summit Materials, LLC
Current assets:
Cash and cash equivalents	64,837	128,508
Accounts receivable, net	195,411	214,518
Costs and estimated earnings in excess of billings	17,079	18,602
Inventories	214,038	213,851
Other current assets	19,245	16,061
Total current assets	510,610	591,540
Property, plant and equipment, less accumulated depreciation, depletion and amortization (March 30, 2019 - $837,896 and December 29, 2018 - $794,251)	1,799,941	1,780,132
Goodwill	1,196,262	1,193,028
Intangible assets, less accumulated amortization (March 30, 2019 - $8,656 and December 29, 2018 - $8,247)	18,051	18,460
Operating lease right-of-use assets	34,403
Other assets	49,990	50,084
Total assets	3,609,257	3,633,244
Current liabilities:
Current portion of debt	4,765	6,354
Current portion of acquisition-related liabilities	34,922	31,770
Accounts payable	102,454	109,008
Accrued expenses	96,707	100,029
Current operating lease liabilities	8,098
Billings in excess of costs and estimated earnings	10,656	11,840
Total current liabilities	257,602	259,001
Long-term debt	1,855,346	1,807,502
Acquisition-related liabilities	37,126	45,354
Noncurrent operating lease liabilities	27,200
Other noncurrent liabilities	132,253	135,956
Total liabilities	2,309,527	2,247,813
Commitments and contingencies (see note 12)
Stockholders’ equity:
Members' equity	1,399,912	1,396,241
Accumulated earnings	(78,758)	12,806
Accumulated other comprehensive income	(21,424)	(23,616)
Total member's interest	1,299,730	1,385,431
Total liabilities and stockholders’ equity	3,609,257	3,633,244
Common Class A
Stockholders’ equity:
Common stock	1,121	1,117
Class B Common Stock
Stockholders’ equity:
Common stock	$ 0	$ 0

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Mar. 30, 2019	Dec. 29, 2018
Property, plant and equipment, less accumulated depreciation, depletion and amortization (March 30, 2019 - $837,896 and December 29, 2018 - $794,251)	$ 837,896	$ 794,251
Intangible assets, less accumulated amortization (March 30, 2019 - $8,656 and December 29, 2018 - $8,247)	8,656	8,247
Deferred tax assets, less valuation allowance (March 30, 2019 - $21,859 and December 29, 2018 - $19,366)	21,859	19,366
Summit Materials, LLC
Property, plant and equipment, less accumulated depreciation, depletion and amortization (March 30, 2019 - $837,896 and December 29, 2018 - $794,251)	837,896	794,251
Intangible assets, less accumulated amortization (March 30, 2019 - $8,656 and December 29, 2018 - $8,247)	$ 8,656	$ 8,247
Common Class A
Common stock, par value (usd per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	1,000,000,000	1,000,000,000
Common stock, shares issued (in shares)	112,067,531	111,658,927
Common stock, shares outstanding (in shares)	112,067,531	111,658,927
Class B Common Stock
Common stock, par value (usd per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	250,000,000	250,000,000
Common stock, shares issued (in shares)	99	99
Common stock, shares outstanding (in shares)	99	99

Unaudited Consolidated Statemen

Unaudited Consolidated Statements of Operations - USD ($) $ in Thousands	3 Months Ended
	Mar. 30, 2019	Mar. 31, 2018
Revenue:
Product	$ 271,641	$ 256,807
Service	34,309	33,109
Net revenue	305,950	289,916
Delivery and subcontract revenue	26,689	24,505
Total revenue	332,639	314,421
Cost of revenue (excluding items shown separately below):
Product	213,726	197,433
Service	26,589	25,923
Net cost of revenue	240,315	223,356
Delivery and subcontract cost	26,689	24,505
Total cost of revenue	267,004	247,861
General and administrative expenses	67,610	69,861
Depreciation, depletion, amortization and accretion	55,388	46,958
Transaction costs	308	1,266
Operating loss	(57,671)	(51,525)
Interest expense	30,105	28,784
Loss on debt financings	14,565	0
Other income, net	(2,803)	(7,655)
Loss from operations before taxes	(99,538)	(72,654)
Income tax benefit	(28,037)	(16,706)
Net loss	(71,501)	(55,948)
Net loss attributable to Summit Holdings	(2,729)	(2,219)
Net loss attributable to Summit Inc.	(68,772)	(53,729)
Summit Materials, LLC
Revenue:
Product	271,641	256,807
Service	34,309	33,109
Net revenue	305,950	289,916
Delivery and subcontract revenue	26,689	24,505
Total revenue	332,639	314,421
Cost of revenue (excluding items shown separately below):
Product	213,726	197,433
Service	26,589	25,923
Net cost of revenue	240,315	223,356
Delivery and subcontract cost	26,689	24,505
Total cost of revenue	267,004	247,861
General and administrative expenses	67,610	69,861
Depreciation, depletion, amortization and accretion	55,388	46,958
Transaction costs	308	1,266
Operating loss	(57,671)	(51,525)
Interest expense	29,937	28,570
Loss on debt financings	14,565	0
Other income, net	(2,803)	(7,655)
Loss from operations before taxes	(99,370)	(72,440)
Income tax benefit	(7,806)	(3,844)
Net loss	(91,564)	(68,596)
Net loss attributable to Summit Inc.	$ (91,564)	$ (68,596)
Common Class A
Loss per share of Class A common stock:
Basic (usd per share)	$ (0.62)	$ (0.49)
Diluted (usd per share)	$ (0.62)	$ (0.49)
Weighted average shares of Class A common stock:
Basic (in shares)	111,811,679	110,659,098
Diluted (in shares)	111,811,679	110,659,098

Unaudited Consolidated Statem_2

Unaudited Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended
	Mar. 30, 2019	Mar. 31, 2018
Comprehensive income (loss)
Net loss	$ (71,501)	$ (55,948)
Other comprehensive income (loss):
Foreign currency translation adjustment	2,358	(3,104)
(Loss) income on cash flow hedges	(166)	995
Less tax effect of other comprehensive income (loss) items	(542)	(520)
Other comprehensive income (loss):	1,650	(2,629)
Comprehensive loss	(69,851)	(58,577)
Less comprehensive loss attributable to Summit Holdings	(2,663)	(2,285)
Comprehensive loss attributable to Summit Inc.	(67,188)	(56,292)
Summit Materials, LLC
Comprehensive income (loss)
Net loss	(91,564)	(68,596)
Other comprehensive income (loss):
Foreign currency translation adjustment	2,358	(3,104)
(Loss) income on cash flow hedges	(166)	995
Other comprehensive income (loss):	2,192	(2,109)
Comprehensive loss attributable to Summit Inc.	$ (89,372)	$ (70,705)

Unaudited Consolidated Statem_3

Unaudited Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 30, 2019	Mar. 31, 2018
Cash flow from operating activities:
Net loss	$ (71,501)	$ (55,948)
Adjustments to reconcile net loss to net cash provided by operating activities:
Depreciation, depletion, amortization and accretion	57,039	45,559
Share-based compensation expense	5,906	8,507
Net gain on asset disposals	(1,735)	(4,077)
Non-cash loss on debt financings	2,850	0
Change in deferred tax asset, net	(28,028)	(17,373)
Other	47	1,579
(Increase) decrease in operating assets, net of acquisitions and dispositions:
Accounts receivable, net	20,118	27,979
Inventories	(705)	(35,248)
Costs and estimated earnings in excess of billings	1,541	(2,678)
Other current assets	(3,447)	(3,202)
Other assets	2,576	747
(Decrease) increase in operating liabilities, net of acquisitions and dispositions:
Accounts payable	(5,431)	(7,742)
Accrued expenses	(6,963)	(8,660)
Billings in excess of costs and estimated earnings	(1,195)	(1,788)
Tax receivable agreement liability	59	822
Other liabilities	(1,807)	156
Net cash used in operating activities	(30,676)	(51,367)
Cash flow from investing activities:
Acquisitions, net of cash acquired	(2,842)	(113,993)
Purchases of property, plant and equipment	(62,188)	(49,505)
Proceeds from the sale of property, plant and equipment	2,797	7,788
Other	(178)	1,500
Net cash used for investing activities	(62,411)	(154,210)
Cash flow from financing activities:
Proceeds from debt issuances	300,000	0
Debt issuance costs	(5,774)	0
Payments on debt	(256,333)	(3,972)
Payments on acquisition-related liabilities	(8,933)	(8,962)
Distributions from partnership	0	(9)
Proceeds from stock option exercises	766	15,475
Other	(501)	(1,820)
Net cash provided by financing activities	29,225	712
Impact of foreign currency on cash	191	(398)
Net (decrease) increase in cash	(63,671)	(205,263)
Cash and cash equivalents—beginning of period	128,508	383,556
Cash and cash equivalents—end of period	64,837	178,293
Summit Materials, LLC
Cash flow from operating activities:
Net loss	(91,564)	(68,596)
Adjustments to reconcile net loss to net cash provided by operating activities:
Depreciation, depletion, amortization and accretion	56,871	45,345
Share-based compensation expense	5,906	8,507
Net gain on asset disposals	(1,735)	(4,077)
Non-cash loss on debt financings	2,850	0
Change in deferred tax asset, net	(7,738)	(3,689)
Other	47	1,579
(Increase) decrease in operating assets, net of acquisitions and dispositions:
Accounts receivable, net	20,118	27,979
Inventories	(705)	(35,248)
Costs and estimated earnings in excess of billings	1,541	(2,678)
Other current assets	(3,447)	(3,202)
Other assets	2,576	747
(Decrease) increase in operating liabilities, net of acquisitions and dispositions:
Accounts payable	(6,126)	(8,328)
Accrued expenses	(6,268)	(8,074)
Billings in excess of costs and estimated earnings	(1,195)	(1,788)
Other liabilities	(1,807)	156
Net cash used in operating activities	(30,676)	(51,367)
Cash flow from investing activities:
Acquisitions, net of cash acquired	(2,842)	(113,993)
Purchases of property, plant and equipment	(62,188)	(49,505)
Proceeds from the sale of property, plant and equipment	2,797	7,788
Other	(178)	1,500
Net cash used for investing activities	(62,411)	(154,210)
Cash flow from financing activities:
Capital contributions by member	766	15,475
Proceeds from debt issuances	300,000	0
Debt issuance costs	(5,774)	0
Payments on debt	(256,333)	(3,972)
Payments on acquisition-related liabilities	(6,433)	(6,462)
Distributions from partnership	(2,500)	(2,509)
Other	(501)	(1,820)
Net cash provided by financing activities	29,225	712
Impact of foreign currency on cash	191	(398)
Net (decrease) increase in cash	(63,671)	(205,263)
Cash and cash equivalents—beginning of period	128,508	383,556
Cash and cash equivalents—end of period	$ 64,837	$ 178,293

Unaudited Consolidated Statem_4

Unaudited Consolidated Statements of Changes in Stockholders' Equity / Members' Interest and Redeemable Noncontrolling Interest - USD ($) $ in Thousands	Total	Summit Materials, LLC	Class A Common Stock	Class B Common Stock	Members' equitySummit Materials, LLC	Accumulated Earnings (Deficit)	Accumulated Earnings (Deficit)Summit Materials, LLC	Accumulated Other Comprehensive Income (Loss)	Accumulated Other Comprehensive Income (Loss)Summit Materials, LLC	Common StockClass A Common Stock	Common StockClass B Common Stock	Additional Paid-in Capital	Noncontrolling Interest in Summit Holdings
Beginning balance at Dec. 30, 2017	$ 1,271,721					$ 95,833		$ 7,386		$ 1,104	$ 0	$ 1,154,220	$ 13,178
Beginning balance at Dec. 30, 2017		$ 1,291,594			$ 1,359,760		$ (51,031)		$ (17,135)
Beginning balance (in shares) at Dec. 30, 2017			110,350,594							110,350,594	100
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net contributed capital		15,475			15,475
Net loss	(55,948)	(68,596)				(53,729)	(68,596)						(2,219)
LP Unit exchanges (in shares)			104,104							104,104
LP Unit exchanges	0									$ 1		485	(486)
Other comprehensive income, net of tax	(2,629)	(2,109)						(2,563)	(2,109)				(66)
Stock option exercises (in shares)										856,915
Stock option exercises	15,477									$ 9		15,468
Share-based compensation	8,507	8,507			8,507		0					8,507
Distributions from partnership	$ (9)												(9)
Distributions		(2,509)			(2,509)
Other (in shares)	1,033,875		1,033,875							176,960
Shares redeemed to settle taxes and other	$ (1,772)	(1,820)			(1,820)					$ 2		(1,774)
Ending balance at Mar. 31, 2018	1,235,347					42,104		4,823		$ 1,116	$ 0	1,176,906	10,398
Ending balance at Mar. 31, 2018		1,240,542			1,379,413		(119,627)		(19,244)
Ending balance (in shares) at Mar. 31, 2018			111,488,573							111,488,573	100
Beginning balance at Dec. 29, 2018	1,342,145					129,739		2,681		$ 1,117	$ 0	1,194,204	14,404
Beginning balance at Dec. 29, 2018		1,385,431			1,396,241		12,806		(23,616)
Beginning balance (in shares) at Dec. 29, 2018			111,658,927	99						111,658,927	99
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net contributed capital		766			766
Net loss	(71,501)	(91,564)				(68,772)	(91,564)						(2,729)
LP Unit exchanges (in shares)			17,500							17,500
LP Unit exchanges	0									$ 0		122	(122)
Other comprehensive income, net of tax	1,650	2,192						1,584	2,192				66
Stock option exercises (in shares)										43,142
Stock option exercises	767									$ 1		766
Share-based compensation	$ 5,906	5,906			5,906		0					5,906
Distributions		(2,500)			(2,500)
Other (in shares)	391,104		391,104							347,962
Shares redeemed to settle taxes and other	$ (492)	(501)			(501)					$ 3		(495)
Ending balance at Mar. 30, 2019	$ 1,278,475					$ 60,967		$ 4,265		$ 1,121	$ 0	$ 1,200,503	$ 11,619
Ending balance at Mar. 30, 2019		$ 1,299,730			$ 1,399,912		$ (78,758)		$ (21,424)
Ending balance (in shares) at Mar. 30, 2019			112,067,531	99						112,067,531	99

Summary of Organization and Sig

Summary of Organization and Significant Accounting Policies	3 Months Ended
	Mar. 30, 2019
Summary Of Significant Accounting Policies And Recent Accounting Pronouncements [Line Items]
Summary of Organization and Significant Accounting Policies	SUMMARY OF ORGANIZATION AND SIGNIFICANT ACCOUNTING POLICIES Summit Materials, Inc. (“Summit Inc.” and, together with its subsidiaries, “Summit,” “we,” “us,” “our” or 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 construction materials, 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, weather conditions and to cyclical changes in construction spending, among other factors. Summit Inc. is a holding corporation operating and controlling all of the business and affairs of Summit Materials Holdings L.P. (“Summit Holdings”) and its subsidiaries and, through Summit Holdings, conducts its business. Summit Inc. owns the majority of the partnership interests of Summit Holdings (see note 9, Stockholders’ Equity). Summit Materials, LLC (“Summit LLC”) an indirect wholly owned subsidiary of Summit Holdings, conducts the majority of our operations. Summit Materials Finance Corp. (“Summit Finance”), an indirect wholly owned subsidiary of Summit LLC, has jointly issued our Senior Notes as described below. Basis of Presentation —These unaudited consolidated financial statements were prepared in accordance with U.S. generally accepted accounting principles (“U.S. GAAP”) for interim financial information, without audit, pursuant to the rules and regulations of the Securities and Exchange Commission (“SEC”). Certain information and footnote disclosures typically included in financial statements prepared in accordance with U.S. GAAP have been condensed or omitted pursuant to such rules and regulations. These unaudited consolidated financial statements should be read in conjunction with the Company's audited consolidated financial statements and the notes thereto as of and for the year ended December 29, 2018 . The Company continues to follow the accounting policies set forth in those audited consolidated financial statements. Management believes that these consolidated interim financial statements include all adjustments, normal and recurring in nature, that are necessary to present fairly the financial position of the Company as of March 30, 2019 , the results of operations for the three months ended March 30, 2019 and March 31, 2018 and cash flows for the three months ended March 30, 2019 and March 31, 2018 . 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 into a holding company structure (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. For a summary of the changes in Summit Inc.’s ownership of Summit Holdings, see Note 9, Stockholders’ Equity. Use of Estimates —Preparation of these consolidated financial statements in conformity with 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, the tax receivable agreement ("TRA") liability, 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 23 U.S. states and in British Columbia, Canada, with the most significant revenue generated in Texas, Utah, Kansas 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 the three months ended March 30, 2019 or March 31, 2018 . Revenue Recognition —We earn revenue from the sale of products, which primarily include aggregates, cement, ready-mix concrete and asphalt, but also include concrete products and plastics components, and from the provision of services, which are primarily paving and related services, but also include landfill operations, the receipt and disposal of waste that is converted to fuel for use in our cement plants and underground storage space rental. Products We earn revenue from the sale of products, which primarily include aggregates, cement, ready-mix concrete and asphalt, but also include concrete products, net of discounts or allowances, if any, and freight and delivery charges billed to customers. Freight and delivery charges associated with cement sales are recorded on a net basis together with freight costs within cost of sales. Revenue for product sales is recognized when evidence of an arrangement exists and when control passes, which generally is when the product is shipped. Services We earn revenue from the provision of services, which are primarily paving and related services, but also include landfill operations, the receipt and disposal of waste that is converted to fuel for use in our cement plants, and underground storage space rental. Revenue from the receipt of waste fuels is recognized when the waste is accepted and a corresponding liability is recognized for the costs to process the waste into fuel for the manufacturing of cement or to ship the waste offsite for disposal in accordance with applicable regulations. Revenue derived from paving and related services is recognized using the percentage of completion method, which approximates progress towards completion. Under the percentage of completion method, we recognize paving and related services revenue as services are rendered. The majority of our construction service contracts are completed within one year, but may occasionally extend beyond this time frame. We estimate profit as the difference between total estimated revenue and total estimated cost of a contract and recognize that profit over the life of the contract based on input measures. We generally measure progress toward completion on long-term paving and related services contracts based on the proportion of costs incurred to date relative to total estimated costs at completion. We include revisions of estimated profits on contracts in earnings under the cumulative catch-up method, under which the effect of revisions in estimates is recognized immediately. If a revised estimate of contract profitability reveals an anticipated loss on the contract, we recognize the loss in the period it is identified. The percentage of completion method of accounting involves the use of various estimating techniques to project costs at completion, and in some cases includes estimates of recoveries asserted against the customer for changes in specifications or other disputes. Contract estimates involve various assumptions and projections relative to the outcome of future events over multiple periods, including future labor productivity and availability, the nature and complexity of the work to be performed, the cost and availability of materials, the effect of delayed performance, and the availability and timing of funding from the customer. These estimates are based on our best judgment. A significant change in one or more of these estimates could affect the profitability of one or more of our contracts. We review our contract estimates regularly to assess revisions in contract values and estimated costs at completion. 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. No material adjustments to a contract were recognized in the three months ended March 30, 2019 . 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 amounts were not billable under the contract terms at the balance sheet date. In accordance with the contract terms, the unbilled receivables at the balance sheet date are expected to be billed in following periods. Billings in excess of costs and estimated earnings represent billings in excess of revenue recognized. Contract assets and liabilities are netted on a contract-by-contract basis. 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. Tax Receivable Agreement — When Class A limited partnership units of Summit Holdings (“LP Units”) are exchanged for shares of Class A common stock of Summit Inc. or Summit Inc. purchases LP Units for cash, this results in increases in Summit Inc.’s share of the tax basis of the tangible and intangible assets, which increases the tax depreciation and amortization deductions that otherwise would not have been available to Summit Inc. These increases in tax basis and tax depreciation and amortization deductions are expected to reduce the amount of cash taxes that we would otherwise be required to pay in the future. Prior to our initial public offering (“IPO”), we entered into a TRA with the pre-IPO owners that requires us to pay the pre-IPO owners or their permitted assignees 85% of the amount of cash savings, if any, in U.S. federal, state, and local income tax that we actually realize as a result of these exchanges. These benefits include (1) increases in the tax basis of tangible and intangible assets of Summit Holdings and certain other tax benefits related to entering into the TRA, (2) tax benefits attributable to payments under the TRA, or (3) under certain circumstances such as an early termination of the TRA, we are deemed to realize, as a result of the increases in tax basis in connection with exchanges by the pre-IPO owners described above and certain other tax benefits attributable to payments under the TRA. We periodically evaluate the realizability of the deferred tax assets resulting from the exchange of LP Units for Class A common stock. If the deferred tax assets are determined to be realizable, we then assess whether payment of amounts under the TRA have become probable. If so, we record a TRA liability equal to 85% of such deferred tax assets, and the remaining 15% as an increase to additional paid-in capital. If a deferred tax asset subject to the TRA is determined not to be realizable and therefore subject to a valuation allowance, we do not record a TRA liability for such deferred tax assets. In subsequent periods, we assess the realizability of all of our deferred tax assets subject to the TRA. Should we determine a deferred tax asset with a valuation allowance is realizable in a subsequent period, the related valuation allowance will be released and consideration of a corresponding TRA liability will be assessed. The realizability of deferred tax assets, including those subject to the TRA, is dependent upon the generation of future taxable income during the periods in which those deferred tax assets become deductible and consideration of prudent and feasible tax-planning strategies. The measurement of the TRA liability is accounted for as a contingent liability. Therefore, once we determine that a payment to a pre-IPO owner has become probable and can be estimated, the estimate of payment will be accrued. New Accounting Standards — In February 2016, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2016-02, Leases (Topic 842), which will result in lessees recognizing most leases on the balance sheet. Lessees are required to disclose more quantitative and qualitative information about the leases than current U.S. GAAP requires. The ASU and subsequent amendments issued in 2018 are effective for public entities for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2018. We adopted the standard effective December 30, 2018 using the modified retrospective approach. The modified retrospective approach provides a method for recording existing leases at adoption. In addition, we elected the package of practical expedients permitted under the transition guidance within the new standard, which among other things, allowed us to carry forward the historical lease classification. In addition, we elected the hindsight practical expedient to determine the lease term for existing leases. The most significant impact upon adoption was the recognition of $36.8 million of operating lease right-of-use assets and $36.8 million operating lease liabilities. The standard had no material impact on our statement of cash flows. In August 2017, the FASB issued ASU No. 2017-12, Derivatives and Hedging (Topic 815): Targeted Improvements to Accounting for Hedging Activities, allowing more financial and nonfinancial hedging strategies to be eligible for hedge accounting. The ASU is effective for fiscal years beginning after December 15, 2018 and interim periods within those fiscal years. The adoption of this new ASU did not have a material impact on our consolidated financial results. In June 2018, the FASB issued ASU No. 2018-07, Compensation—Stock Compensation (Topic 718): Improvements to Nonemployee Share-Based Payment Accounting, increasing the scope of Topic 718 to include share-based payment transactions for acquiring goods and services from nonemployees. The ASU is effective for fiscal years beginning after December 15, 2018 and interim periods within those fiscal years. The adoption of this new ASU did not have a material impact on our consolidated financial results.
Summit Materials, LLC
Summary Of Significant Accounting Policies And Recent Accounting Pronouncements [Line Items]
Summary of Organization and Significant Accounting Policies	SUMMARY OF ORGANIZATION AND SIGNIFICANT ACCOUNTING POLICIES Summit Materials, LLC (“Summit LLC” and, together with its subsidiaries, “Summit,” “we,” “us,” “our” or 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 construction materials, 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, weather 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”) 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, including Summit LLC. Basis of Presentation —These unaudited consolidated financial statements were prepared in accordance with U.S. generally accepted accounting principles (“U.S. GAAP”) for interim financial information, without audit, pursuant to the rules and regulations of the Securities and Exchange Commission (“SEC”). Certain information and footnote disclosures typically included in financial statements prepared in accordance with U.S. GAAP have been condensed or omitted pursuant to such rules and regulations. These unaudited consolidated financial statements should be read in conjunction with the Company’s audited consolidated financial statements and the notes thereto as of and for the year ended December 29, 2018 . The Company continues to follow the accounting policies set forth in those audited consolidated financial statements. Management believes that these consolidated interim financial statements include all adjustments, normal and recurring in nature, that are necessary to present fairly the financial position of the Company as of March 30, 2019 , the results of operations for the three months ended March 30, 2019 and March 31, 2018 and cash flows for the three months ended March 30, 2019 and March 31, 2018 . Use of Estimates —Preparation of these consolidated financial statements in conformity with 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 23 U.S. states and in British Columbia, Canada, with the most significant revenue generated in Texas, Utah, Kansas 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 the three months ended March 30, 2019 or March 31, 2018 . Revenue Recognition —We earn revenue from the sale of products, which primarily include aggregates, cement, ready-mix concrete and asphalt, but also include concrete products and plastics components, and from the provision of services, which are primarily paving and related services, but also include landfill operations, the receipt and disposal of waste that is converted to fuel for use in our cement plants and underground storage space rental. Products We earn revenue from the sale of products, which primarily include aggregates, cement, ready-mix concrete and asphalt, but also include concrete products, net of discounts or allowances, if any, and freight and delivery charges billed to customers. Freight and delivery charges associated with cement sales are recorded on a net basis together with freight costs within cost of sales. Revenue for product sales is recognized when evidence of an arrangement exists and when control passes, which generally is when the product is shipped. Services We earn revenue from the provision of services, which are primarily paving and related services, but also include landfill operations, the receipt and disposal of waste that is converted to fuel for use in our cement plants, and underground storage space rental. Revenue from the receipt of waste fuels is recognized when the waste is accepted and a corresponding liability is recognized for the costs to process the waste into fuel for the manufacturing of cement or to ship the waste offsite for disposal in accordance with applicable regulations. Revenue derived from paving and related services is recognized using the percentage of completion method, which approximates progress towards completion. Under the percentage of completion method, we recognize paving and related services revenue as services are rendered. The majority of our construction service contracts are completed within one year, but may occasionally extend beyond this time frame. We estimate profit as the difference between total estimated revenue and total estimated cost of a contract and recognize that profit over the life of the contract based on input measures. We generally measure progress toward completion on long-term paving and related services contracts based on the proportion of costs incurred to date relative to total estimated costs at completion. We include revisions of estimated profits on contracts in earnings under the cumulative catch-up method, under which the effect of revisions in estimates is recognized immediately. If a revised estimate of contract profitability reveals an anticipated loss on the contract, we recognize the loss in the period it is identified. The percentage of completion method of accounting involves the use of various estimating techniques to project costs at completion, and in some cases includes estimates of recoveries asserted against the customer for changes in specifications or other disputes. Contract estimates involve various assumptions and projections relative to the outcome of future events over multiple periods, including future labor productivity and availability, the nature and complexity of the work to be performed, the cost and availability of materials, the effect of delayed performance, and the availability and timing of funding from the customer. These estimates are based on our best judgment. A significant change in one or more of these estimates could affect the profitability of one or more of our contracts. We review our contract estimates regularly to assess revisions in contract values and estimated costs at completion. 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. No material adjustments to a contract were recognized in the three months ended March 30, 2019 . 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 amounts were not billable under the contract terms at the balance sheet date. In accordance with the contract terms, the unbilled receivables at the balance sheet date are expected to be billed in following periods. Billings in excess of costs and estimated earnings represent billings in excess of revenue recognized. Contract assets and liabilities are netted on a contract-by-contract basis. New Accounting Standards — In February 2016, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2016-02, Leases (Topic 842), which will result in lessees recognizing most leases on the balance sheet. Lessees are required to disclose more quantitative and qualitative information about the leases than current U.S. GAAP requires. The ASU and subsequent amendments issued in 2018 are effective for public entities for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2018. We adopted the standard effective December 30, 2018 using the modified retrospective approach. The modified retrospective approach provides a method for recording existing leases at adoption. In addition, we elected the package of practical expedients permitted under the transition guidance within the new standard, which among other things, allowed us to carry forward the historical lease classification. In addition, we elected the hindsight practical expedient to determine the lease term for existing leases. The most significant impact upon adoption was the recognition of $36.8 million of operating lease right-of-use assets and $36.8 million operating lease liabilities. The standard had no material impact on our statement of cash flows. In August 2017, the FASB issued ASU No. 2017-12, Derivatives and Hedging (Topic 815): Targeted Improvements to Accounting for Hedging Activities, allowing more financial and nonfinancial hedging strategies to be eligible for hedge accounting. The ASU is effective for fiscal years beginning after December 15, 2018 and interim periods within those fiscal years. The adoption of this new ASU did not have a material impact on our consolidated financial results. In June 2018, the FASB issued ASU No. 2018-07, Compensation-Stock Compensation (Topic 718): Improvements to Nonemployee Share-Based Payment Accounting, increasing the scope of Topic 718 to include share-based payment transactions for acquiring goods and services from nonemployees. The ASU is effective for fiscal years beginning after December 15, 2018 and interim periods within those fiscal years. The adoption of this new ASU did not have a material impact on our consolidated financial results.

Goodwill and Intangibles

Goodwill and Intangibles	3 Months Ended
	Mar. 30, 2019
Business Acquisition [Line Items]
Goodwill and Intangibles	GOODWILL AND INTANGIBLES The Company has completed numerous acquisitions since its formation, 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. Changes in the carrying amount of goodwill, by reportable segment, from December 29, 2018 to March 30, 2019 are summarized as follows: West East Cement Total Balance, December 29, 2018 $ 580,567 $ 406,805 $ 204,656 $ 1,192,028 Acquisitions (1) 1,143 879 — 2,022 Foreign currency translation adjustments 1,212 — — 1,212 Balance, March 30, 2019 $ 582,922 $ 407,684 $ 204,656 $ 1,195,262 _____________________________________________________________________________________________ (1) Reflects goodwill from 2019 acquisitions and working capital adjustments from prior year acquisitions. The Company’s intangible assets are primarily composed of goodwill, mineral lease agreements and reserve rights. The assets related to mineral 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. The reserve rights relate to aggregate reserves to which the Company has the rights of ownership, but does 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: March 30, 2019 December 29, 2018 Gross Carrying Amount Accumulated Amortization Net Carrying Amount Gross Carrying Amount Accumulated Amortization Net Carrying Amount Mineral leases $ 19,064 $ (5,548 ) $ 13,516 $ 19,064 $ (5,259 ) $ 13,805 Reserve rights 6,234 (2,024 ) 4,210 6,234 (1,940 ) 4,294 Trade names 1,000 (883 ) 117 1,000 (858 ) 142 Other 409 (201 ) 208 409 (190 ) 219 Total intangible assets $ 26,707 $ (8,656 ) $ 18,051 $ 26,707 $ (8,247 ) $ 18,460 Amortization expense totaled $0.4 million and $0.3 million for the three months ended March 30, 2019 and March 31, 2018 , respectively. The estimated amortization expense for the intangible assets for each of the five years subsequent to March 30, 2019 is as follows: 2019 (nine months) $ 1,189 2020 1,510 2021 1,475 2022 1,482 2023 1,349 2024 1,254 Thereafter 9,792 Total $ 18,051
Summit Materials, LLC
Business Acquisition [Line Items]
Goodwill and Intangibles	GOODWILL AND INTANGIBLES The Company has completed numerous acquisitions since its formation, 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. Changes in the carrying amount of goodwill, by reportable segment, from December 29, 2018 to March 30, 2019 are summarized as follows: West East Cement Total Balance, December 29, 2018 $ 581,567 $ 406,805 $ 204,656 $ 1,193,028 Acquisitions (1) 1,143 879 — 2,022 Foreign currency translation adjustments 1,212 — — 1,212 Balance, March 30, 2019 $ 583,922 $ 407,684 $ 204,656 $ 1,196,262 _______________________________________________________________________ (1) Reflects goodwill from 2019 acquisitions and working capital adjustments from prior year acquisitions. The Company’s intangible assets are primarily composed of goodwill, mineral lease agreements and reserve rights. The assets related to mineral 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. The reserve rights relate to aggregate reserves to which the Company has the rights of ownership, but does 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: March 30, 2019 December 29, 2018 Gross Carrying Amount Accumulated Amortization Net Carrying Amount Gross Carrying Amount Accumulated Amortization Net Carrying Amount Mineral leases $ 19,064 $ (5,548 ) $ 13,516 $ 19,064 $ (5,259 ) $ 13,805 Reserve rights 6,234 (2,024 ) 4,210 6,234 (1,940 ) 4,294 Trade names 1,000 (883 ) 117 1,000 (858 ) 142 Other 409 (201 ) 208 409 (190 ) 219 Total intangible assets $ 26,707 $ (8,656 ) $ 18,051 $ 26,707 $ (8,247 ) $ 18,460 Amortization expense totaled $0.4 million and $0.3 million for the three months ended March 30, 2019 and March 31, 2018 , respectively. The estimated amortization expense for the intangible assets for each of the five years subsequent to March 30, 2019 is as follows: 2019 (nine months) $ 1,189 2020 1,510 2021 1,475 2022 1,482 2023 1,349 2024 1,254 Thereafter 9,792 Total $ 18,051

Revenue Recognition

Revenue Recognition	3 Months Ended
	Mar. 30, 2019
Revenue from External Customer [Line Items]
Revenue Recognition	REVENUE RECOGNITION We derive our revenue predominantly by selling construction materials, products and providing paving and related services. Construction materials consist of aggregates and cement. Products consist of related downstream products, including ready-mix concrete, asphalt paving mix and concrete products. Paving and related service revenue is generated primarily from the asphalt paving services that we provide. Revenue by product for the three months ended March 30, 2019 and March 31, 2018 is as follows: Three months ended March 30, 2019 March 31, 2018 Revenue by product*: Aggregates $ 87,872 $ 67,450 Cement 32,499 33,117 Ready-mix concrete 117,320 122,015 Asphalt 23,038 18,141 Paving and related services 34,345 34,336 Other 37,565 39,362 Total revenue $ 332,639 $ 314,421 *Revenue from liquid asphalt terminals is included in asphalt revenue. The following table outlines the significant changes in contract assets and contract liability balances from December 29, 2018 to March 30, 2019 . Also included in the table is the net change in estimate as a percentage of aggregate revenue for such contracts: Costs and estimated earnings in excess of billings Billings in excess of costs and estimated earnings Balance - December 29, 2018 $ 18,602 $ 11,840 Changes in revenue billed, contract price or cost estimates (1,541 ) (1,195 ) Other 18 11 Balance - March 30, 2019 $ 17,079 $ 10,656 Accounts receivable, net consisted of the following as of March 30, 2019 and December 29, 2018 : March 30, 2019 December 29, 2018 Trade accounts receivable $ 167,337 $ 157,601 Construction contract receivables 20,755 47,994 Retention receivables 12,902 15,010 Receivables from related parties 575 629 Accounts receivable 201,569 221,234 Less: Allowance for doubtful accounts (6,158 ) (6,716 ) Accounts receivable, net $ 195,411 $ 214,518 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
Revenue from External Customer [Line Items]
Revenue Recognition	REVENUE RECOGNITION We derive our revenue predominantly by selling construction materials, products and providing paving and related services. Construction materials consist of aggregates and cement. Products consist of related downstream products, including ready-mix concrete, asphalt paving mix and concrete products. Paving and related service revenue is generated primarily from the asphalt paving services that we provide. Revenue by product for the three months ended March 30, 2019 and March 31, 2018 is as follows: Three months ended March 30, March 31, 2019 2018 Revenue by product*: Aggregates $ 87,872 $ 67,450 Cement 32,499 33,117 Ready-mix concrete 117,320 122,015 Asphalt 23,038 18,141 Paving and related services 34,345 34,336 Other 37,565 39,362 Total revenue $ 332,639 $ 314,421 *Revenue from liquid asphalt terminals is included in asphalt revenue. The following table outlines the significant changes in contract assets and contract liability balances from December 29, 2018 to March 30, 2019 . Also included in the table is the net change in estimate as a percentage of aggregate revenue for such contracts: Costs and estimated Billings in excess earnings in of costs and excess of billings estimated earnings Balance - December 29, 2018 $ 18,602 $ 11,840 Changes in revenue billed, contract price or cost estimates (1,541 ) (1,195 ) Other 18 11 Balance - March 30, 2019 $ 17,079 $ 10,656 Accounts receivable, net consisted of the following as of March 30, 2019 and December 29, 2018 : March 30, December 29, 2019 2018 Trade accounts receivable $ 167,337 $ 157,601 Construction contract receivables 20,755 47,994 Retention receivables 12,902 15,010 Receivables from related parties 575 629 Accounts receivable 201,569 221,234 Less: Allowance for doubtful accounts (6,158 ) (6,716 ) Accounts receivable, net $ 195,411 $ 214,518 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	3 Months Ended
	Mar. 30, 2019
Inventory [Line Items]
Inventories	INVENTORIES Inventories consisted of the following as of March 30, 2019 and December 29, 2018 : March 30, 2019 December 29, 2018 Aggregate stockpiles $ 146,132 $ 151,300 Finished goods 35,275 34,993 Work in process 7,947 7,478 Raw materials 24,684 20,080 Total $ 214,038 $ 213,851
Summit Materials, LLC
Inventory [Line Items]
Inventories	INVENTORIES Inventories consisted of the following as of March 30, 2019 and December 29, 2018 : March 30, 2019 December 29, 2018 Aggregate stockpiles $ 146,132 $ 151,300 Finished goods 35,275 34,993 Work in process 7,947 7,478 Raw materials 24,684 20,080 Total $ 214,038 $ 213,851

Accrued Expenses

Accrued Expenses	3 Months Ended
	Mar. 30, 2019
Schedule Of Accrued Expenses [Line Items]
Accrued Expenses	ACCRUED EXPENSES Accrued expenses consisted of the following as of March 30, 2019 and December 29, 2018 : March 30, 2019 December 29, 2018 Interest $ 14,553 $ 26,223 Payroll and benefits 19,126 15,952 Finance lease obligations 17,407 15,557 Insurance 16,071 13,625 Non-income taxes 9,876 7,442 Professional fees 625 1,408 Other (1) 18,818 20,284 Total $ 96,476 $ 100,491 (1) Consists primarily of subcontractor and working capital settlement accruals.
Summit Materials, LLC
Schedule Of Accrued Expenses [Line Items]
Accrued Expenses	ACCRUED EXPENSES Accrued expenses consisted of the following as of March 30, 2019 and December 29, 2018 : March 30, 2019 December 29, 2018 Interest $ 14,553 $ 26,223 Payroll and benefits 19,126 15,952 Finance lease obligations 17,407 15,557 Insurance 16,071 13,625 Non-income taxes 10,107 7,674 Professional fees 625 1,408 Other (1) 18,818 19,590 Total $ 96,707 $ 100,029 _______________________________________________________________________ (1) Consists primarily of subcontractor and working capital settlement accruals.

Debt

Debt	3 Months Ended
	Mar. 30, 2019
Debt Instrument [Line Items]
Debt	DEBT Debt consisted of the following as of March 30, 2019 and December 29, 2018 : March 30, 2019 December 29, 2018 Term Loan, due 2024: $627.4 million and $630.6 million, net of $1.3 million and $1.3 million discount at March 30, 2019 and December 29, 2018, respectively $ 626,147 $ 629,268 8 1 ⁄ 2 % Senior Notes, due 2022 — 250,000 6 1 ⁄ 8 % Senior Notes, due 2023: $650.0 million, net of $1.0 million and $1.1 million discount at March 30, 2019 and December 29, 2018, respectively 648,952 648,891 5 1 ⁄ 8 % Senior Notes, due 2025 300,000 300,000 6 1 ⁄ 2 % Senior Notes, due 2027 300,000 — Total 1,875,099 1,828,159 Current portion of long-term debt 4,765 6,354 Long-term debt $ 1,870,334 $ 1,821,805 The contractual payments of long-term debt, including current maturities, for the five years subsequent to March 30, 2019 , are as follows: 2019 (nine months) $ 3,177 2020 7,942 2021 6,354 2022 6,354 2023 656,354 2024 597,253 Thereafter 600,000 Total 1,877,434 Less: Original issue net discount (2,335 ) Less: Capitalized loan costs (14,988 ) Total debt $ 1,860,111 Senior Notes —On March 15, 2019, Summit LLC and Summit Finance (together, the “Issuers”) issued $300.0 million in aggregate principal amount of 6.500% senior notes due March 15, 2027 (the “2027 Notes”). The 2027 Notes were issued at 100.0% of their par value with proceeds of $296.3 million , net of related fees and expenses. Interest on the 2027 Notes is payable semi-annually on March 15 and September 15 of each year commencing on September 15, 2019. In March 2019, using the proceeds from the 2027 Notes, all of the outstanding $250.0 million 8.500% senior notes due 2022 (the “2022 Notes”) were redeemed at a price equal to par plus an applicable premium and the indenture under which the 2022 Notes were issued was satisfied and discharged. As a result of the extinguishment, charges of $14.6 million were recognized in the quarter ended March 30, 2019, which included charges of $11.7 million for the applicable redemption premium and $2.9 million for the write-off of deferred financing fees. In 2017, the Issuers issued $300.0 million of 5.125% senior notes due June 1, 2025 (the “2025 Notes”). The 2025 Notes were issued at 100.0% of their par value with proceeds of $295.4 million , net of related fees and expenses. The 2025 Notes were issued under an indenture dated June 1, 2017 (as amended and supplemented, the “2017 Indenture”). The 2017 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 2017 Indenture also contains customary events of default. Interest on the 2025 Notes is payable semi-annually on June 1 and December 1 of each year commencing on December 1, 2017. In 2015, the Issuers issued $650.0 million of 6.125% senior notes due July 2023 (the “2023 Notes” and collectively with the 2025 Notes and the 2027 Notes, the “Senior Notes”). 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 2017 Indenture. Interest on the 2023 Notes is payable semi-annually in arrears on January 15 and July 15 of each year. As of March 30, 2019 and December 29, 2018 , the Company was in compliance with all financial covenants under the applicable indentures. 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 $345.0 million (the “Senior Secured Credit Facilities”). Under the Senior Secured Credit Facilities, required principal repayments of 0.25% of the refinanced aggregate amount of term debt are due on the last business day of each March, June, September and December commencing with the March 2018 payment. The unpaid principal balance is due in full on the maturity date, which is November 21, 2024. On February 25, 2019, Summit LLC entered into Incremental Amendment No. 4 to the credit agreement governing the Senior Secured Credit Facilities (the “Credit Agreement”) which, among other things, increased the total amount available under the revolving credit facility to $345.0 million and extended the maturity date of the Credit Agreement to February 2024. During 2018 and 2017, Summit LLC entered into three different amendments to the Credit Agreement, which among other things, reduced the applicable margin in respect to the outstanding principal amount at the time of the respective amendments. 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 2.00% 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 3.00% for LIBOR rate loans. There were no outstanding borrowings under the revolving credit facility as of March 30, 2019 and December 29, 2018 , leaving remaining borrowing capacity of $329.8 million as of March 30, 2019 , which is net of $15.2 million of outstanding letters of credit. The outstanding letters of credit are renewed annually and support required bonding on construction projects, large leases, workers compensation claims 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 March 30, 2019 and December 29, 2018 , 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. The following table presents the activity for the deferred financing fees for the three months ended March 30, 2019 and March 31, 2018 : Deferred financing fees Balance—December 29, 2018 $ 15,475 Loan origination fees 5,774 Amortization (998 ) Write off of deferred financing fees (2,851 ) Balance—March 30, 2019 $ 17,400 Balance - December 30, 2017 $ 19,033 Amortization (1,013 ) Balance - March 31, 2018 $ 18,020 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 March 30, 2019 or December 29, 2018 .
Summit Materials, LLC
Debt Instrument [Line Items]
Debt	DEBT Debt consisted of the following as of March 30, 2019 and December 29, 2018 : March 30, 2019 December 29, 2018 Term Loan, due 2024: $627.4 million and $630.6 million, net of $1.3 million and $1.3 million discount at March 30, 2019 and December 29, 2018, respectively $ 626,147 $ 629,268 8 1/2 % Senior Notes, due 2022 — 250,000 6 1/8 % Senior Notes, due 2023: $650.0 million, net of $1.0 million and $1.1 million discount at March 30, 2019 and December 29, 2018, respectively 648,952 648,891 5 1⁄8 % Senior Notes, due 2025 300,000 300,000 6 1⁄2 % Senior Notes, due 2027 300,000 — Total 1,875,099 1,828,159 Current portion of long-term debt 4,765 6,354 Long-term debt $ 1,870,334 $ 1,821,805 The contractual payments of long-term debt, including current maturities, for the five years subsequent to March 30, 2019 , are as follows: 2019 (nine months) $ 3,177 2020 7,942 2021 6,354 2022 6,354 2023 656,354 2024 597,253 Thereafter 600,000 Total 1,877,434 Less: Original issue net discount (2,335 ) Less: Capitalized loan costs (14,988 ) Total debt $ 1,860,111 Senior Notes —On March 15, 2019, Summit LLC and Summit Materials Finance Corp., an indirect wholly-owned subsidiary of Summit LLC (“Finance Corp.” and together with Summit LLC, the “Issuers”) issued $300.0 million in aggregate principal amount of 6.500% senior notes due March 15, 2027 (the “2027 Notes”). The 2027 Notes were issued at 100.0% of their par value with proceeds of $296.3 million , net of related fees and expenses. Interest on the 2027 Notes is payable semi-annually on March 15 and September 15 of each year commencing on September 15, 2019. In March 2019, using the proceeds from the 2027 Notes, all of the outstanding $250.0 million 8.500% senior notes due 2022 (the “2022 Notes”) were redeemed at a price equal to par plus an applicable premium and the indenture under which the 2022 Notes were issued was satisfied and discharged. As a result of the extinguishment, charges of $14.6 million were recognized in the quarter ended March 30, 2019, which included charges of $11.7 million for the applicable redemption premium and $2.9 million for the write-off of deferred financing fees. In 2017, the Issuers issued $300.0 million of 5.125% senior notes due June 1, 2025 (the “2025 Notes”). The 2025 Notes were issued at 100.0% of their par value with proceeds of $295.4 million , net of related fees and expenses. The 2025 Notes were issued under an indenture dated June 1, 2017 (as amended and supplemented, the “2017 Indenture”). The 2017 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 2017 Indenture also contains customary events of default. Interest on the 2025 Notes is payable semi-annually on June 1 and December 1 of each year commencing on December 1, 2017. In 2015, the Issuers issued $650.0 million of 6.125% senior notes due July 2023 (the “2023 Notes” and collectively with the 2025 Notes and the 2027 Notes, the “Senior Notes”). 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 2017 Indenture. Interest on the 2023 Notes is payable semi-annually in arrears on January 15 and July 15 of each year. As of March 30, 2019 and December 29, 2018 , the Company was in compliance with all financial covenants under the applicable indentures. 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 $345.0 million (the “Senior Secured Credit Facilities”). Under the Senior Secured Credit Facilities, required principal repayments of 0.25% of the refinanced aggregate amount of term debt are due on the last business day of each March, June, September and December, commencing with the March 2018 payment. The unpaid principal balance is due in full on the maturity date, which is November 21, 2024. On February 25, 2019, Summit LLC entered into Incremental Amendment No. 4 to the credit agreement governing the Senior Secured Credit Facilities (the “Credit Agreement”) which, among other things, increased the total amount available under the revolving credit facility to $345.0 million and extended the maturity date of the Credit Agreement to February 2024. During 2018 and 2017, Summit LLC entered into three different amendments to the Credit Agreement, which among other things, reduced the applicable margin in respect to the outstanding principal amount at the time of the respective amendments. 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 2.00% 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 3.00% for LIBOR rate loans. There were no outstanding borrowings under the revolving credit facility as of March 30, 2019 and December 29, 2018 , leaving remaining borrowing capacity of $329.8 million as of March 30, 2019 , which is net of $15.2 million of outstanding letters of credit. The outstanding letters of credit are renewed annually and support required bonding on construction projects, large leases, workers compensation claims 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 March 30, 2019 and December 29, 2018 , 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. The following table presents the activity for the deferred financing fees for the three months ended March 30, 2019 and March 31, 2018 : Deferred financing fees Balance—December 29, 2018 $ 15,475 Loan origination fees 5,774 Amortization (998 ) Write off of deferred financing fees (2,851 ) Balance—March 30, 2019 $ 17,400 Balance - December 30, 2017 $ 19,033 Amortization (1,013 ) Balance - March 31, 2018 $ 18,020 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 March 30, 2019 or December 29, 2018 .

Income Taxes

Income Taxes	3 Months Ended
	Mar. 30, 2019
Income Taxes [Line Items]
Income Taxes	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. Our income tax benefit was $28.0 million and $16.7 million in the three months ended March 30, 2019 and March 31, 2018 , respectively. For the three months ended March 30, 2019 , the effective tax rate for Summit Inc. differs from the federal rate primarily due to (1) state taxes, (2) tax depletion expense in excess of the expense recorded under U.S. GAAP, (3) the minority interest in the Summit Holdings partnership that is allocated outside of the Company (4) various other items such as limitations on meals and entertainment, certain stock compensation and other costs and (5) unrecognized tax benefits. For the three months ended March 31, 2018 , the effective tax rate for Summit Inc. differs from the federal rate primarily due to (1) tax depletion expense in excess of the expense recorded under U.S. GAAP, (2) the minority interest in the Summit Holdings partnership that is allocated outside of the Company and (3) various other items such as limitations on meals and entertainment, certain stock compensation and other costs. As of March 30, 2019 and December 29, 2018 , Summit Inc. had a valuation allowance of $21.9 million and $19.4 million , respectively, which relates to certain deferred tax assets in taxable entities where realization is not more likely than not. Summit Inc. and its subsidiaries expect additional unrecognized tax benefits in 2019 that if recognized would affect the annual effective tax rate, and included that in its estimate of those amounts in its annual effective tax rate. We did not recognize interest or penalties related to this amount as it is offset by other attributes. No material interest or penalties were recognized in income tax expense during the three months ended March 30, 2019 and March 31, 2018 . No uncertain tax benefits were recognized in the three months ended March 31, 2018. Tax Receivable Agreement —The Company is party to a TRA with certain current and former holders of LP Units that provides for the payment by Summit Inc. to exchanging holders of LP Units of 85% of the benefits, if any, that Summit Inc. actually realizes (or, under certain circumstances such as an early termination of the TRA, is deemed to realize) as a result of increases in the tax basis of tangible and intangible assets of Summit Holdings and certain other tax benefits related to entering into the TRA, including tax benefits attributable to payments under the TRA. In the three months ended March 30, 2019 , 17,500 LP Units 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 net new deferred tax assets of approximately $0.1 million . As we determined that the deferred tax assets created from these exchanges are realizable and payment under the TRA is considered probable, we have recorded 85% of the increase in deferred tax assets as TRA liability and the remainder as an increase in additional paid in capital. As of March 30, 2019 and December 29, 2018 , we had recorded $309.7 million and $310.3 million of TRA liability, respectively, of which $0.6 million was classified as accrued expenses as of December 29, 2018 . 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 Summit Inc. multiplied by an assumed tax rate equal to the highest effective marginal combined U.S. federal, state and local income tax rate in New York, New York. We did not make any tax distributions in the three months ended March 30, 2019 and made $0.1 million in the three months ended March 31, 2018 .
Summit Materials, LLC
Income Taxes [Line Items]
Income Taxes	INCOME TAXES Summit LLC is a limited liability company and passes its tax attributes for federal and state tax purposes to its parent company and is generally not subject to federal or state income tax. However, certain subsidiary entities file federal, state and Canadian income tax returns due to their status as taxable entities in the respective jurisdiction. The effective income tax rate for the C Corporations differs 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. Summit LLC expects additional unrecognized tax benefits in 2019 that if recognized would affect the annual effective tax rate, and included that in its estimate of those amounts in its annual effective tax rate. We did not recognize interest or penalties related to this amount as it is offset by other attributes. No material interest or penalties were recognized in income tax expense during the three months ended March 30, 2019 and March 31, 2018 .

Earnings Per Share

Earnings Per Share	3 Months Ended
	Mar. 30, 2019
Earnings Per Share [Abstract]
Earnings Per Share	EARNINGS PER SHARE Basic earnings per share is computed by dividing net earnings by the weighted average common shares outstanding and diluted net earnings is computed by dividing net earnings, adjusted for changes in the earnings 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 and diluted loss per share: Three months ended March 30, 2019 March 31, 2018 Net loss attributable to Summit Inc. $ (68,772 ) $ (53,729 ) Weighted average shares of Class A stock outstanding 111,811,679 110,659,098 Basic and diluted loss per share $ (0.62 ) $ (0.49 ) Excluded from the above calculations were the shares noted below as they were antidilutive: Three months ended March 30, 2019 March 31, 2018 Antidilutive shares: LP Units 3,418,018 3,585,516 Time-vesting stock options 3,192,674 3,296,133 Warrants 100,037 100,037 Time-vesting restricted stock units 1,589,396 854,482 Market-based restricted stock units 419,247 295,252

Stockholders' Equity_Members' I

Stockholders' Equity/Members' Interest	3 Months Ended
	Mar. 30, 2019
Schedule of Capitalization, Equity [Line Items]
Stockholders' Equity	STOCKHOLDERS’ EQUITY During 2019 and 2018, certain limited partners of Summit Holdings exchanged their LP Units for shares of Class A common stock of Summit Inc. The following table summarizes the changes in our ownership of Summit Holdings: Summit Inc. LP Units Total Summit Inc. Balance — December 29, 2018 111,658,927 3,435,518 115,094,445 97.0 % Exchanges during period 17,500 (17,500 ) — Other equity transactions 391,104 — 391,104 Balance — March 30, 2019 112,067,531 3,418,018 115,485,549 97.0 % Balance — December 30, 2017 110,350,594 3,689,620 114,040,214 96.8 % Exchanges during period 104,104 (104,104 ) — Other equity transactions 1,033,875 — 1,033,875 Balance — March 31, 2018 111,488,573 3,585,516 115,074,089 96.9 % As a result of the Reorganization, Summit Inc. is Summit Holdings’ primary beneficiary and thus consolidates Summit Holdings in its consolidated financial statements with a corresponding noncontrolling interest reclassification, which was 3.0% as of March 30, 2019 and December 29, 2018 . Accumulated other comprehensive income (loss) —The changes in each component of accumulated other comprehensive income (loss) consisted of the following: Change in retirement plans Foreign currency translation adjustments Cash flow hedge adjustments Accumulated other comprehensive income (loss) Balance — December 29, 2018 $ 3,573 $ (2,147 ) $ 1,255 $ 2,681 Foreign currency translation adjustment, net of tax — 1,704 — 1,704 Loss on cash flow hedges, net of tax — — (120 ) (120 ) Balance — March 30, 2019 $ 3,573 $ (443 ) $ 1,135 $ 4,265 Balance — December 30, 2017 $ 2,364 $ 4,637 $ 385 $ 7,386 Foreign currency translation adjustment, net of tax — (3,772 ) — (3,772 ) Income on cash flow hedges, net of tax — — 1,209 1,209 Balance — March 31, 2018 $ 2,364 $ 865 $ 1,594 $ 4,823
Summit Materials, LLC
Schedule of Capitalization, Equity [Line Items]
Members' Interest	MEMBERS’ INTEREST 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 29, 2018 $ (4,392 ) $ (19,370 ) $ 146 $ (23,616 ) Foreign currency translation adjustment — 2,358 — 2,358 Loss on cash flow hedges — — (166 ) (166 ) Balance — March 30, 2019 $ (4,392 ) $ (17,012 ) $ (20 ) $ (21,424 ) Balance - December 30, 2017 $ (7,181 ) $ (17,790 ) $ (2,473 ) $ (27,444 ) Foreign currency translation adjustment — 706 — 706 Income on cash flow hedges — — 412 412 Balance - March 31, 2018 $ (7,181 ) $ (17,084 ) $ (2,061 ) $ (26,326 )

Supplemental Cash Flow Informat

Supplemental Cash Flow Information	3 Months Ended
	Mar. 30, 2019
Schedule Of Cash Flow Supplemental [Line Items]
Supplemental Cash Flow Information	SUPPLEMENTAL CASH FLOW INFORMATION Supplemental cash flow information is as follows: Three months ended March 30, 2019 March 31, 2018 Cash payments: Interest $ 21,126 $ 26,927 Income (refund) taxes (20 ) 1,582 Operating cash payments on operating leases 2,837 — Operating cash payments on finance leases 699 — Finance cash payments on finance leases 2,580 — Non cash financing activities: Right of use assets obtained in exchange for operating lease obligations $ 1,608 $ — Right of use assets obtained in exchange for finance leases obligations 9,442 — Exchange of LP Units to shares of Class A common stock 277 3,325
Summit Materials, LLC
Schedule Of Cash Flow Supplemental [Line Items]
Supplemental Cash Flow Information	SUPPLEMENTAL CASH FLOW INFORMATION Supplemental cash flow information is as follows: Three months ended March 30, 2019 March 31, 2018 Cash payments: Interest $ 21,126 $ 26,927 Income (refund) taxes (20 ) 1,582 Operating cash payments on operating leases 2,837 — Operating cash payments on finance leases 699 — Finance cash payments on finance leases 2,580 — Non cash financing activities: Right of use assets obtained in exchange for operating lease obligations $ 1,608 $ — Right of use assets obtained in exchange for finance leases obligations 9,442 —

Leases

Leases	3 Months Ended
	Mar. 30, 2019
Lessee, Lease, Description [Line Items]
LEASES	LEASES We lease construction and office equipment, distribution facilities and office space. Leases with an initial term of 12 months or less, including month to month leases, are not recorded on the balance sheet. Lease expense for short-term leases is recognized on a straight line basis over the lease term. For lease agreements entered into or reassessed after the adoption of ASC 842, we combine lease and nonlease components. While we also own mineral leases for mining operations, those leases are outside the scope of ASC 842. Assets acquired under finance leases are included in property, plant and equipment. Many of our leases include options to purchase the leased equipment. The depreciable life of assets and leasehold improvements are limited by the expected lease term, unless there is a transfer of title or purchase option reasonably certain of exercise. Our lease agreements do not contain any material residual value guarantees or material restrictive covenants. The components of lease expense were as follows: March 30, 2019 Operating lease cost $ 2,455 Variable lease cost 72 Short-term lease cost 6,581 Financing lease cost: Amortization of right-of-use assets 2,623 Interest on lease liabilities 755 Total lease cost $ 12,486 Supplemental balance sheet information related to leases: Operating leases: Operating lease right-of-use assets $ 34,403 Current operating lease liabilities $ 8,098 Noncurrent operating lease liabilities 27,200 Total operating lease liabilities $ 35,298 Finance leases: Property and equipment, gross $ 75,132 Less accumulated depreciation (20,581 ) Property and equipment, net $ 54,551 Current finance lease liabilities $ 17,407 Long-term finance lease liabilities 37,851 Total finance lease liabilities $ 55,258 March 30, 2019 Lease Term Discount Rate (years) (%) Weighted average: Operating leases 7.9 5.6 % Finance lease 2.8 5.3 % Maturities of lease liabilities were as follows: Operating Leases Finance Leases 2019 (nine months) $ 7,228 $ 15,217 2020 8,737 15,703 2021 7,138 17,974 2022 4,370 6,556 2023 3,419 1,509 2024 2,235 1,750 Thereafter 11,212 2,667 Total lease payments 44,339 61,376 Less imputed interest (9,041 ) (6,118 ) Present value of lease payments $ 35,298 $ 55,258 As previously disclosed, our future minimum lease payment obligations as of December 29, 2018 were as follows: Operating Leases 2019 $ 9,479 2020 8,101 2021 6,701 2022 4,279 2023 3,411
LEASES	LEASES We lease construction and office equipment, distribution facilities and office space. Leases with an initial term of 12 months or less, including month to month leases, are not recorded on the balance sheet. Lease expense for short-term leases is recognized on a straight line basis over the lease term. For lease agreements entered into or reassessed after the adoption of ASC 842, we combine lease and nonlease components. While we also own mineral leases for mining operations, those leases are outside the scope of ASC 842. Assets acquired under finance leases are included in property, plant and equipment. Many of our leases include options to purchase the leased equipment. The depreciable life of assets and leasehold improvements are limited by the expected lease term, unless there is a transfer of title or purchase option reasonably certain of exercise. Our lease agreements do not contain any material residual value guarantees or material restrictive covenants. The components of lease expense were as follows: March 30, 2019 Operating lease cost $ 2,455 Variable lease cost 72 Short-term lease cost 6,581 Financing lease cost: Amortization of right-of-use assets 2,623 Interest on lease liabilities 755 Total lease cost $ 12,486 Supplemental balance sheet information related to leases: Operating leases: Operating lease right-of-use assets $ 34,403 Current operating lease liabilities $ 8,098 Noncurrent operating lease liabilities 27,200 Total operating lease liabilities $ 35,298 Finance leases: Property and equipment, gross $ 75,132 Less accumulated depreciation (20,581 ) Property and equipment, net $ 54,551 Current finance lease liabilities $ 17,407 Long-term finance lease liabilities 37,851 Total finance lease liabilities $ 55,258 March 30, 2019 Lease Term Discount Rate (years) (%) Weighted average: Operating leases 7.9 5.6 % Finance lease 2.8 5.3 % Maturities of lease liabilities were as follows: Operating Leases Finance Leases 2019 (nine months) $ 7,228 $ 15,217 2020 8,737 15,703 2021 7,138 17,974 2022 4,370 6,556 2023 3,419 1,509 2024 2,235 1,750 Thereafter 11,212 2,667 Total lease payments 44,339 61,376 Less imputed interest (9,041 ) (6,118 ) Present value of lease payments $ 35,298 $ 55,258 As previously disclosed, our future minimum lease payment obligations as of December 29, 2018 were as follows: Operating Leases 2019 $ 9,479 2020 8,101 2021 6,701 2022 4,279 2023 3,411
Summit Materials, LLC
Lessee, Lease, Description [Line Items]
LEASES	LEASES We lease construction and office equipment, distribution facilities and office space. Leases with an initial term of 12 months or less, including month to month leases, are not recorded on the balance sheet. Lease expense for short-term leases is recognized on a straight line basis over the lease term. For lease agreements entered into or reassessed after the adoption of ASC 842, we combine lease and nonlease components. While we also own mineral leases for mining operations, those leases are outside the scope of ASC 842. Assets acquired under finance leases are included in property, plant and equipment. Many of our leases include options to purchase the leased equipment. The depreciable life of assets and leasehold improvements are limited by the expected lease term, unless there is a transfer of title or purchase option reasonably certain of exercise. Our lease agreements do not contain any material residual value guarantees or material restrictive covenants. The components of lease expense were as follows: March 30, 2019 Operating lease cost $ 2,455 Variable lease cost 72 Short-term lease cost 6,581 Financing lease cost: Amortization of right-of-use assets 2,623 Interest on lease liabilities 755 Total lease cost $ 12,486 Supplemental balance sheet information related to leases: Operating leases: Operating lease right-of-use assets $ 34,403 Current operating lease liabilities $ 8,098 Noncurrent operating lease liabilities 27,200 Total operating lease liabilities $ 35,298 Finance leases: Property and equipment, gross $ 75,132 Less accumulated depreciation (20,581 ) Property and equipment, net $ 54,551 Current finance lease liabilities $ 17,407 Long-term finance lease liabilities 37,851 Total finance lease liabilities $ 55,258 March 30, 2019 Lease Term Discount Rate (years) (%) Weighted average: Operating leases 7.9 5.6 % Finance lease 2.8 5.3 % Maturities of lease liabilities were as follows: Operating Leases Finance Leases 2019 (nine months) $ 7,228 $ 15,217 2020 8,737 15,703 2021 7,138 17,974 2022 4,370 6,556 2023 3,419 1,509 2024 2,235 1,750 Thereafter 11,212 2,667 Total lease payments 44,339 61,376 Less imputed interest (9,041 ) (6,118 ) Present value of lease payments $ 35,298 $ 55,258 As previously disclosed, our future minimum lease payment obligations as of December 29, 2018 were as follows: Operating Leases 2019 $ 9,479 2020 8,101 2021 6,701 2022 4,279 2023 3,411
LEASES	LEASES We lease construction and office equipment, distribution facilities and office space. Leases with an initial term of 12 months or less, including month to month leases, are not recorded on the balance sheet. Lease expense for short-term leases is recognized on a straight line basis over the lease term. For lease agreements entered into or reassessed after the adoption of ASC 842, we combine lease and nonlease components. While we also own mineral leases for mining operations, those leases are outside the scope of ASC 842. Assets acquired under finance leases are included in property, plant and equipment. Many of our leases include options to purchase the leased equipment. The depreciable life of assets and leasehold improvements are limited by the expected lease term, unless there is a transfer of title or purchase option reasonably certain of exercise. Our lease agreements do not contain any material residual value guarantees or material restrictive covenants. The components of lease expense were as follows: March 30, 2019 Operating lease cost $ 2,455 Variable lease cost 72 Short-term lease cost 6,581 Financing lease cost: Amortization of right-of-use assets 2,623 Interest on lease liabilities 755 Total lease cost $ 12,486 Supplemental balance sheet information related to leases: Operating leases: Operating lease right-of-use assets $ 34,403 Current operating lease liabilities $ 8,098 Noncurrent operating lease liabilities 27,200 Total operating lease liabilities $ 35,298 Finance leases: Property and equipment, gross $ 75,132 Less accumulated depreciation (20,581 ) Property and equipment, net $ 54,551 Current finance lease liabilities $ 17,407 Long-term finance lease liabilities 37,851 Total finance lease liabilities $ 55,258 March 30, 2019 Lease Term Discount Rate (years) (%) Weighted average: Operating leases 7.9 5.6 % Finance lease 2.8 5.3 % Maturities of lease liabilities were as follows: Operating Leases Finance Leases 2019 (nine months) $ 7,228 $ 15,217 2020 8,737 15,703 2021 7,138 17,974 2022 4,370 6,556 2023 3,419 1,509 2024 2,235 1,750 Thereafter 11,212 2,667 Total lease payments 44,339 61,376 Less imputed interest (9,041 ) (6,118 ) Present value of lease payments $ 35,298 $ 55,258 As previously disclosed, our future minimum lease payment obligations as of December 29, 2018 were as follows: Operating Leases 2019 $ 9,479 2020 8,101 2021 6,701 2022 4,279 2023 3,411

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 30, 2019
Loss Contingencies [Line Items]
Commitments and Contingencies	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 current pending or threatened claims and litigation will not have a material effect on the Company’s consolidated financial position, results of operations or liquidity. The Company records legal fees as incurred. In March 2018, we were notified of an investigation by the Canadian Competition Bureau (the “CCB”) into pricing practices by certain asphalt paving contractors in British Columbia, including Winvan Paving, Ltd. (“Winvan”). We believe the investigation is focused on time periods prior to our April 2017 acquisition of Winvan and we are cooperating with the CCB. 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. The Company has asset retirement obligations arising from regulatory and contractual requirements to perform reclamation activities at the time certain quarries and landfills are closed. As of March 30, 2019 and December 29, 2018 , $28.1 million and $26.9 million , respectively, were included in other noncurrent liabilities on the consolidated balance sheets and $4.0 million and $4.1 million , respectively, were included in accrued expenses for future reclamation costs. The total undiscounted anticipated costs for site reclamation as of March 30, 2019 and December 29, 2018 were $93.3 million and $92.5 million , respectively. 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
Loss Contingencies [Line Items]
Commitments and Contingencies	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 current pending or threatened claims and litigation will not have a material effect on the Company’s consolidated financial position, results of operations or liquidity. The Company records legal fees as incurred. In March 2018, we were notified of an investigation by the Canadian Competition Bureau (the “CCB”) into pricing practices by certain asphalt paving contractors in British Columbia, including Winvan Paving, Ltd. (“Winvan”). We believe the investigation is focused on time periods prior to our April 2017 acquisition of Winvan and we are cooperating with the CCB. 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. The Company has asset retirement obligations arising from regulatory and contractual requirements to perform reclamation activities at the time certain quarries and landfills are closed. As of March 30, 2019 and December 29, 2018 , $28.1 million and $26.9 million , respectively, were included in other noncurrent liabilities on the consolidated balance sheets and $4.0 million and $4.1 million , respectively, were included in accrued expenses for future reclamation costs. The total undiscounted anticipated costs for site reclamation as of March 30, 2019 and December 29, 2018 were $93.3 million and $92.5 million , respectively. 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 .

Fair Value

Fair Value	3 Months Ended
	Mar. 30, 2019
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	FAIR VALUE 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 interest rate derivative expires in September 2019. 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 (loss) 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 March 30, 2019 and December 29, 2018 was: March 30, 2019 December 29, 2018 Current portion of acquisition-related liabilities and Accrued expenses: Contingent consideration $ 4,568 $ 1,394 Cash flow hedges — — Acquisition-related liabilities and Other noncurrent liabilities: Contingent consideration $ 1,205 $ 5,175 Cash flow hedges — — The fair value of contingent consideration was based on unobservable, or Level 3, inputs, including projected probability-weighted cash payments and a 10.0% 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 is based on observable, or Level 2, inputs such as interest rates, bond yields and prices in inactive markets. There were no material valuation adjustments to contingent consideration or derivatives as of March 30, 2019 and March 31, 2018 . 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 March 30, 2019 and December 29, 2018 was: March 30, 2019 December 29, 2018 Fair Value Carrying Value Fair Value Carrying Value Level 2 Long-term debt(1) $ 1,865,816 $ 1,875,099 $ 1,777,722 $ 1,828,159 Level 3 Current portion of deferred consideration and noncompete obligations(2) 32,854 32,854 32,876 32,876 Long term portion of deferred consideration and noncompete obligations(3) 37,703 37,703 44,293 44,293 (1) $4.8 million and $6.4 million were included in current portion of debt as of March 30, 2019 and December 29, 2018 , respectively. (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.
Summit Materials, LLC
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	FAIR VALUE 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 interest rate derivative expires in September 2019. 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 (loss) 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 March 30, 2019 and December 29, 2018 was: March 30, 2019 December 29, 2018 Current portion of acquisition-related liabilities and Accrued expenses: Contingent consideration $ 4,568 $ 1,394 Cash flow hedges — — Acquisition-related liabilities and Other noncurrent liabilities: Contingent consideration $ 1,205 $ 5,175 Cash flow hedges — — The fair value of contingent consideration was based on unobservable, or Level 3, inputs, including projected probability-weighted cash payments and a 10.0% 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 is based on observable, or Level 2, inputs such as interest rates, bond yields and prices in inactive markets. There were no material valuation adjustments to contingent consideration or derivatives as of March 30, 2019 and March 31, 2018 . 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 March 30, 2019 and December 29, 2018 was: March 30, 2019 December 29, 2018 Fair Value Carrying Value Fair Value Carrying Value Level 2 Long-term debt(1) $ 1,865,816 $ 1,875,099 $ 1,777,722 $ 1,828,159 Level 3 Current portion of deferred consideration and noncompete obligations(2) 30,354 30,354 30,376 30,376 Long term portion of deferred consideration and noncompete obligations(3) 35,921 35,921 40,179 40,179 (1) $4.8 million and $6.4 million were included in current portion of debt as of March 30, 2019 and December 29, 2018 , respectively. (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.

Segment Information

Segment Information	3 Months Ended
	Mar. 30, 2019
Segment Reporting Information [Line Items]
Segment Information	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, our Company’s Chief Operating Decision Maker (“CODM”). The CODM primarily evaluates the performance of the Company’s 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 March 30, 2019 and December 29, 2018 and for the three months ended March 30, 2019 and March 31, 2018 : Three months ended March 30, 2019 March 31, 2018 Revenue*: West $ 181,945 $ 181,713 East 113,388 95,157 Cement 37,306 37,551 Total revenue $ 332,639 $ 314,421 *Intercompany sales are immaterial and the presentation above only reflects sales to external customers. Three months ended March 30, 2019 March 31, 2018 Loss from operations before taxes $ (99,538 ) $ (72,654 ) Interest expense 30,105 28,784 Depreciation, depletion and amortization 54,807 46,543 Accretion 581 415 Loss on debt financings 14,565 — Transaction costs 308 1,266 Non-cash compensation 5,906 8,507 Other (146 ) (7,348 ) Total Adjusted EBITDA $ 6,588 $ 5,513 Total Adjusted EBITDA by Segment: West $ 14,298 $ 16,173 East 3,242 (3,203 ) Cement (2,587 ) 3,667 Corporate and other (8,365 ) (11,124 ) Total Adjusted EBITDA $ 6,588 $ 5,513 Three months ended March 30, 2019 March 31, 2018 Purchases of property, plant and equipment West $ 30,375 $ 28,909 East 24,428 14,464 Cement 6,893 4,468 Total reportable segments 61,696 47,841 Corporate and other 492 1,664 Total purchases of property, plant and equipment $ 62,188 $ 49,505 Three months ended March 30, 2019 March 31, 2018 Depreciation, depletion, amortization and accretion: West $ 23,925 $ 22,151 East 20,211 17,727 Cement 10,300 6,370 Total reportable segments 54,436 46,248 Corporate and other 952 710 Total depreciation, depletion, amortization and accretion $ 55,388 $ 46,958 March 30, 2019 December 29, 2018 Total assets: West $ 1,379,580 $ 1,370,501 East 1,269,669 1,253,640 Cement 875,966 877,586 Total reportable segments 3,525,215 3,501,727 Corporate and other 336,146 355,914 Total $ 3,861,361 $ 3,857,641
Summit Materials, LLC
Segment Reporting Information [Line Items]
Segment Information	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, our Company’s Chief Operating Decision Maker (“CODM”). The CODM primarily evaluates the performance of the Company’s 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 March 30, 2019 and December 29, 2018 and for the three months ended March 30, 2019 and March 31, 2018 : Three months ended March 30, March 31, 2019 2018 Revenue*: West $ 181,945 $ 181,713 East 113,388 95,157 Cement 37,306 37,551 Total revenue $ 332,639 $ 314,421 *Intercompany sales are immaterial and the presentation above only reflects sales to external customers. Three months ended March 30, March 31, 2019 2018 Loss from operations before taxes $ (99,370 ) $ (72,440 ) Interest expense 29,937 28,570 Depreciation, depletion and amortization 54,807 46,543 Accretion 581 415 Loss on debt financings 14,565 — Transaction costs 308 1,266 Non-cash compensation 5,906 8,507 Other (146 ) (7,348 ) Total Adjusted EBITDA $ 6,588 $ 5,513 Total Adjusted EBITDA by Segment: West $ 14,298 $ 16,173 East 3,242 (3,203 ) Cement (2,587 ) 3,667 Corporate and other (8,365 ) (11,124 ) Total Adjusted EBITDA $ 6,588 $ 5,513 Three months ended March 30, 2019 March 31, 2018 Purchases of property, plant and equipment West $ 30,375 $ 28,909 East 24,428 14,464 Cement 6,893 4,468 Total reportable segments 61,696 47,841 Corporate and other 492 1,664 Total purchases of property, plant and equipment $ 62,188 $ 49,505 Three months ended March 30, March 31, 2019 2018 Depreciation, depletion, amortization and accretion: West $ 23,925 $ 22,151 East 20,211 17,727 Cement 10,300 6,370 Total reportable segments 54,436 46,248 Corporate and other 952 710 Total depreciation, depletion, amortization and accretion $ 55,388 $ 46,958 March 30, 2019 December 29, 2018 Total assets: West $ 1,379,580 $ 1,370,501 East 1,269,669 1,253,640 Cement 875,966 877,586 Total reportable segments 3,525,215 3,501,727 Corporate and other 84,042 131,517 Total $ 3,609,257 $ 3,633,244

Guarantor and Non-Guarantor Fin

Guarantor and Non-Guarantor Financial Information	3 Months Ended
	Mar. 30, 2019
Summit Materials, LLC
Guarantor and Non-Guarantor Financial Information	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. Finance Corp. does not and will not have any assets or operations other than as may be incidental to its activities as a co-issuer of the Senior Notes and other indebtedness. 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. 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 March 30, 2019 100% Owned Non- Issuers Guarantors Guarantors Eliminations Consolidated Assets Current assets: Cash and cash equivalents $ 69,094 $ 1,327 $ 3,733 $ (9,317 ) $ 64,837 Accounts receivable, net 9 182,644 12,934 (176 ) 195,411 Intercompany receivables 480,922 601,070 — (1,081,992 ) — Cost and estimated earnings in excess of billings — 15,609 1,470 — 17,079 Inventories — 210,662 3,376 — 214,038 Other current assets 1,963 13,908 3,374 — 19,245 Total current assets 551,988 1,025,220 24,887 (1,091,485 ) 510,610 Property, plant and equipment, net 12,817 1,727,295 59,829 — 1,799,941 Goodwill — 1,138,807 57,455 — 1,196,262 Intangible assets, net — 18,051 — — 18,051 Operating lease right-of-use assets 3,819 25,004 5,580 — 34,403 Other assets 3,270,321 153,303 1,005 (3,374,639 ) 49,990 Total assets $ 3,838,945 $ 4,087,680 $ 148,756 $ (4,466,124 ) $ 3,609,257 Liabilities and Member’s Interest Current liabilities: Current portion of debt $ 4,765 $ — $ — $ — $ 4,765 Current portion of acquisition-related liabilities — 34,922 — — 34,922 Accounts payable 2,435 92,173 8,022 (176 ) 102,454 Accrued expenses 37,556 66,582 1,886 (9,317 ) 96,707 Current operating lease liabilities 721 6,365 1,012 — 8,098 Intercompany payables 630,962 434,273 16,757 (1,081,992 ) — Billings in excess of costs and estimated earnings — 10,129 527 — 10,656 Total current liabilities 676,439 644,444 28,204 (1,091,485 ) 257,602 Long-term debt 1,855,346 — — — 1,855,346 Acquisition-related liabilities — 37,126 — — 37,126 Noncurrent operating lease liabilities 4,058 18,777 4,365 — 27,200 Other noncurrent liabilities 3,372 222,786 77,412 (171,317 ) 132,253 Total liabilities 2,539,215 923,133 109,981 (1,262,802 ) 2,309,527 Total member's interest 1,299,730 3,164,547 38,775 (3,203,322 ) 1,299,730 Total liabilities and member’s interest $ 3,838,945 $ 4,087,680 $ 148,756 $ (4,466,124 ) $ 3,609,257 Condensed Consolidating Balance Sheets December 29, 2018 100% Owned Non- Issuers Guarantors Guarantors Eliminations Consolidated Assets Current assets: Cash and cash equivalents $ 117,219 $ 8,440 $ 7,719 $ (4,870 ) $ 128,508 Accounts receivable, net — 199,538 15,165 (185 ) 214,518 Intercompany receivables 500,765 624,427 — (1,125,192 ) — Cost and estimated earnings in excess of billings — 17,711 891 — 18,602 Inventories — 210,149 3,702 — 213,851 Other current assets 1,953 11,308 2,800 — 16,061 Total current assets 619,937 1,071,573 30,277 (1,130,247 ) 591,540 Property, plant and equipment, net 13,300 1,709,083 57,749 — 1,780,132 Goodwill — 1,136,785 56,243 — 1,193,028 Intangible assets, net — 18,460 — — 18,460 Other assets 3,292,851 154,080 947 (3,397,794 ) 50,084 Total assets $ 3,926,088 $ 4,089,981 $ 145,216 $ (4,528,041 ) $ 3,633,244 Liabilities and Member’s Interest Current liabilities: Current portion of debt $ 6,354 $ — $ — $ — $ 6,354 Current portion of acquisition-related liabilities — 31,770 — — 31,770 Accounts payable 4,712 92,132 12,349 (185 ) 109,008 Accrued expenses 45,146 57,826 1,927 (4,870 ) 100,029 Intercompany payables 673,175 436,564 15,453 (1,125,192 ) — Billings in excess of costs and estimated earnings — 11,347 493 — 11,840 Total current liabilities 729,387 629,639 30,222 (1,130,247 ) 259,001 Long-term debt 1,807,502 — — — 1,807,502 Acquisition-related liabilities — 45,354 — — 45,354 Other noncurrent liabilities 3,768 226,137 77,368 (171,317 ) 135,956 Total liabilities 2,540,657 901,130 107,590 (1,301,564 ) 2,247,813 Total member's interest 1,385,431 3,188,851 37,626 (3,226,477 ) 1,385,431 Total liabilities and member’s interest $ 3,926,088 $ 4,089,981 $ 145,216 $ (4,528,041 ) $ 3,633,244 Condensed Consolidating Statements of Operations For the three months ended March 30, 2019 100% Owned Non- Issuers Guarantors Guarantors Eliminations Consolidated Revenue $ — $ 318,181 $ 15,641 $ (1,183 ) $ 332,639 Cost of revenue (excluding items shown separately below) — 256,166 12,021 (1,183 ) 267,004 General and administrative expenses 14,930 50,032 2,956 — 67,918 Depreciation, depletion, amortization and accretion 952 52,920 1,516 — 55,388 Operating (loss) income (15,882 ) (40,937 ) (852 ) — (57,671 ) Other (income) loss, net 43,611 (1,942 ) (403 ) (29,504 ) 11,762 Interest expense (income) 31,697 (2,964 ) 1,204 — 29,937 Gain on sale of business — — — — — Income from operations before taxes (91,190 ) (36,031 ) (1,653 ) 29,504 (99,370 ) Income tax expense 374 (7,737 ) (443 ) — (7,806 ) Net income attributable to member of Summit Materials, LLC $ (91,564 ) $ (28,294 ) $ (1,210 ) $ 29,504 $ (91,564 ) Comprehensive income attributable to member of Summit Materials, LLC $ (89,372 ) $ (28,128 ) $ (3,568 ) $ 31,696 $ (89,372 ) Condensed Consolidating Statements of Operations For the three months ended March 31, 2018 100% Owned Non- Issuers Guarantors Guarantors Eliminations Consolidated Revenue $ — $ 300,658 $ 15,181 $ (1,418 ) $ 314,421 Cost of revenue (excluding items shown separately below) — 238,127 11,152 (1,418 ) 247,861 General and administrative expenses 20,947 47,177 3,003 — 71,127 Depreciation, depletion, amortization and accretion 710 44,993 1,255 — 46,958 Operating (loss) income (21,657 ) (29,639 ) (229 ) — (51,525 ) Other income, net 17,365 (6,858 ) 51 (18,213 ) (7,655 ) Interest expense (income) 29,582 (2,203 ) 1,191 — 28,570 Income from operations before taxes (68,604 ) (20,578 ) (1,471 ) 18,213 (72,440 ) Income tax expense (benefit) (8 ) (3,454 ) (382 ) — (3,844 ) Net income attributable to member of Summit Materials, LLC $ (68,596 ) $ (17,124 ) $ (1,089 ) $ 18,213 $ (68,596 ) Comprehensive income (loss) attributable to member of Summit Materials, LLC $ (70,705 ) $ (18,119 ) $ 2,015 $ 16,104 $ (70,705 ) Condensed Consolidating Statements of Cash Flows For the three months ended March 30, 2019 100% Owned Non- Issuers Guarantors Guarantors Eliminations Consolidated Net cash (used in) provided by operating activities $ (57,399 ) $ 26,570 $ 153 $ — $ (30,676 ) Cash flow from investing activities: Acquisitions, net of cash acquired — (2,842 ) — — (2,842 ) Purchase of property, plant and equipment (492 ) (57,326 ) (4,370 ) — (62,188 ) Proceeds from the sale of property, plant, and equipment — 2,791 6 — 2,797 Other — (178 ) — — (178 ) Net cash used for investing activities (492 ) (57,555 ) (4,364 ) — (62,411 ) Cash flow from financing activities: Proceeds from investment by member (2,075 ) 2,841 — — 766 Net proceeds from debt issuance 300,000 — — — 300,000 Loans received from and payments made on loans from other Summit Companies (26,242 ) 30,576 113 (4,447 ) — Payments on long-term debt (253,178 ) (3,076 ) (79 ) — (256,333 ) Payments on acquisition-related liabilities — (6,433 ) — — (6,433 ) Debt issuance costs (5,774 ) — — — (5,774 ) Distributions from partnership (2,500 ) — — — (2,500 ) Other (465 ) (36 ) — — (501 ) Net cash (used in) provided by financing activities 9,766 23,872 34 (4,447 ) 29,225 Impact of cash on foreign currency — — 191 — 191 Net decrease in cash (48,125 ) (7,113 ) (3,986 ) (4,447 ) (63,671 ) Cash — Beginning of period 117,219 8,440 7,719 (4,870 ) 128,508 Cash — End of period $ 69,094 $ 1,327 $ 3,733 $ (9,317 ) $ 64,837 Condensed Consolidating Statements of Cash Flows For the three months ended March 31, 2018 100% Owned Non- Issuers Guarantors Guarantors Eliminations Consolidated Net cash (used in) provided by operating activities $ (38,210 ) $ (15,050 ) $ 1,893 $ — $ (51,367 ) Cash flow from investing activities: Acquisitions, net of cash acquired — (113,993 ) — — (113,993 ) Purchase of property, plant and equipment (1,664 ) (46,363 ) (1,478 ) — (49,505 ) Proceeds from the sale of property, plant, and equipment — 7,668 120 — 7,788 Other — 1,500 — — 1,500 Net cash used for investing activities (1,664 ) (151,188 ) (1,358 ) — (154,210 ) Cash flow from financing activities: Proceeds from investment by member (73,661 ) 89,136 — — 15,475 Loans received from and payments made on loans from other Summit Companies (83,090 ) 82,599 (2,192 ) 2,683 — Payments on long-term debt (1,588 ) (2,380 ) (4 ) — (3,972 ) Payments on acquisition-related liabilities — (6,462 ) — — (6,462 ) Distributions from partnership (2,509 ) — — — (2,509 ) Other (827 ) (960 ) (33 ) — (1,820 ) Net cash provided by financing activities (161,675 ) 161,933 (2,229 ) 2,683 712 Impact of cash on foreign currency — — (398 ) — (398 ) Net increase in cash (201,549 ) (4,305 ) (2,092 ) 2,683 (205,263 ) Cash — Beginning of period 370,741 10,254 14,933 (12,372 ) 383,556 Cash — End of period $ 169,192 $ 5,949 $ 12,841 $ (9,689 ) $ 178,293

Summary of Organization and S_2

Summary of Organization and Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 30, 2019
Summary Of Significant Accounting Policies And Recent Accounting Pronouncements [Line Items]
Basis of Presentation	Basis of Presentation —These unaudited consolidated financial statements were prepared in accordance with U.S. generally accepted accounting principles (“U.S. GAAP”) for interim financial information, without audit, pursuant to the rules and regulations of the Securities and Exchange Commission (“SEC”). Certain information and footnote disclosures typically included in financial statements prepared in accordance with U.S. GAAP have been condensed or omitted pursuant to such rules and regulations. These unaudited consolidated financial statements should be read in conjunction with the Company's audited consolidated financial statements and the notes thereto as of and for the year ended December 29, 2018 . The Company continues to follow the accounting policies set forth in those audited consolidated financial statements. Management believes that these consolidated interim financial statements include all adjustments, normal and recurring in nature, that are necessary to present fairly the financial position of the Company as of March 30, 2019 , the results of operations for the three months ended March 30, 2019 and March 31, 2018 and cash flows for the three months ended March 30, 2019 and March 31, 2018 .
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 into a holding company structure (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. For a summary of the changes in Summit Inc.’s ownership of Summit Holdings, see Note 9, Stockholders’ Equity.
Use of Estimates	Use of Estimates —Preparation of these consolidated financial statements in conformity with 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, the tax receivable agreement ("TRA") liability, 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 23 U.S. states and in British Columbia, Canada, with the most significant revenue generated in Texas, Utah, Kansas 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 the three months ended March 30, 2019 or March 31, 2018 .
Revenue Recognition	Revenue Recognition —We earn revenue from the sale of products, which primarily include aggregates, cement, ready-mix concrete and asphalt, but also include concrete products and plastics components, and from the provision of services, which are primarily paving and related services, but also include landfill operations, the receipt and disposal of waste that is converted to fuel for use in our cement plants and underground storage space rental. Products We earn revenue from the sale of products, which primarily include aggregates, cement, ready-mix concrete and asphalt, but also include concrete products, net of discounts or allowances, if any, and freight and delivery charges billed to customers. Freight and delivery charges associated with cement sales are recorded on a net basis together with freight costs within cost of sales. Revenue for product sales is recognized when evidence of an arrangement exists and when control passes, which generally is when the product is shipped. Services We earn revenue from the provision of services, which are primarily paving and related services, but also include landfill operations, the receipt and disposal of waste that is converted to fuel for use in our cement plants, and underground storage space rental. Revenue from the receipt of waste fuels is recognized when the waste is accepted and a corresponding liability is recognized for the costs to process the waste into fuel for the manufacturing of cement or to ship the waste offsite for disposal in accordance with applicable regulations. Revenue derived from paving and related services is recognized using the percentage of completion method, which approximates progress towards completion. Under the percentage of completion method, we recognize paving and related services revenue as services are rendered. The majority of our construction service contracts are completed within one year, but may occasionally extend beyond this time frame. We estimate profit as the difference between total estimated revenue and total estimated cost of a contract and recognize that profit over the life of the contract based on input measures. We generally measure progress toward completion on long-term paving and related services contracts based on the proportion of costs incurred to date relative to total estimated costs at completion. We include revisions of estimated profits on contracts in earnings under the cumulative catch-up method, under which the effect of revisions in estimates is recognized immediately. If a revised estimate of contract profitability reveals an anticipated loss on the contract, we recognize the loss in the period it is identified. The percentage of completion method of accounting involves the use of various estimating techniques to project costs at completion, and in some cases includes estimates of recoveries asserted against the customer for changes in specifications or other disputes. Contract estimates involve various assumptions and projections relative to the outcome of future events over multiple periods, including future labor productivity and availability, the nature and complexity of the work to be performed, the cost and availability of materials, the effect of delayed performance, and the availability and timing of funding from the customer. These estimates are based on our best judgment. A significant change in one or more of these estimates could affect the profitability of one or more of our contracts. We review our contract estimates regularly to assess revisions in contract values and estimated costs at completion. 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. No material adjustments to a contract were recognized in the three months ended March 30, 2019 . 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 amounts were not billable under the contract terms at the balance sheet date. In accordance with the contract terms, the unbilled receivables at the balance sheet date are expected to be billed in following periods. Billings in excess of costs and estimated earnings represent billings in excess of revenue recognized. Contract assets and liabilities are netted on a contract-by-contract basis.
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.
Tax Receivable Agreement	Tax Receivable Agreement — When Class A limited partnership units of Summit Holdings (“LP Units”) are exchanged for shares of Class A common stock of Summit Inc. or Summit Inc. purchases LP Units for cash, this results in increases in Summit Inc.’s share of the tax basis of the tangible and intangible assets, which increases the tax depreciation and amortization deductions that otherwise would not have been available to Summit Inc. These increases in tax basis and tax depreciation and amortization deductions are expected to reduce the amount of cash taxes that we would otherwise be required to pay in the future. Prior to our initial public offering (“IPO”), we entered into a TRA with the pre-IPO owners that requires us to pay the pre-IPO owners or their permitted assignees 85% of the amount of cash savings, if any, in U.S. federal, state, and local income tax that we actually realize as a result of these exchanges. These benefits include (1) increases in the tax basis of tangible and intangible assets of Summit Holdings and certain other tax benefits related to entering into the TRA, (2) tax benefits attributable to payments under the TRA, or (3) under certain circumstances such as an early termination of the TRA, we are deemed to realize, as a result of the increases in tax basis in connection with exchanges by the pre-IPO owners described above and certain other tax benefits attributable to payments under the TRA. We periodically evaluate the realizability of the deferred tax assets resulting from the exchange of LP Units for Class A common stock. If the deferred tax assets are determined to be realizable, we then assess whether payment of amounts under the TRA have become probable. If so, we record a TRA liability equal to 85% of such deferred tax assets, and the remaining 15% as an increase to additional paid-in capital. If a deferred tax asset subject to the TRA is determined not to be realizable and therefore subject to a valuation allowance, we do not record a TRA liability for such deferred tax assets. In subsequent periods, we assess the realizability of all of our deferred tax assets subject to the TRA. Should we determine a deferred tax asset with a valuation allowance is realizable in a subsequent period, the related valuation allowance will be released and consideration of a corresponding TRA liability will be assessed. The realizability of deferred tax assets, including those subject to the TRA, is dependent upon the generation of future taxable income during the periods in which those deferred tax assets become deductible and consideration of prudent and feasible tax-planning strategies. The measurement of the TRA liability is accounted for as a contingent liability. Therefore, once we determine that a payment to a pre-IPO owner has become probable and can be estimated, the estimate of payment will be accrued.
New Accounting Standards	New Accounting Standards — In February 2016, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2016-02, Leases (Topic 842), which will result in lessees recognizing most leases on the balance sheet. Lessees are required to disclose more quantitative and qualitative information about the leases than current U.S. GAAP requires. The ASU and subsequent amendments issued in 2018 are effective for public entities for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2018. We adopted the standard effective December 30, 2018 using the modified retrospective approach. The modified retrospective approach provides a method for recording existing leases at adoption. In addition, we elected the package of practical expedients permitted under the transition guidance within the new standard, which among other things, allowed us to carry forward the historical lease classification. In addition, we elected the hindsight practical expedient to determine the lease term for existing leases. The most significant impact upon adoption was the recognition of $36.8 million of operating lease right-of-use assets and $36.8 million operating lease liabilities. The standard had no material impact on our statement of cash flows. In August 2017, the FASB issued ASU No. 2017-12, Derivatives and Hedging (Topic 815): Targeted Improvements to Accounting for Hedging Activities, allowing more financial and nonfinancial hedging strategies to be eligible for hedge accounting. The ASU is effective for fiscal years beginning after December 15, 2018 and interim periods within those fiscal years. The adoption of this new ASU did not have a material impact on our consolidated financial results. In June 2018, the FASB issued ASU No. 2018-07, Compensation—Stock Compensation (Topic 718): Improvements to Nonemployee Share-Based Payment Accounting, increasing the scope of Topic 718 to include share-based payment transactions for acquiring goods and services from nonemployees. The ASU is effective for fiscal years beginning after December 15, 2018 and interim periods within those fiscal years. The adoption of this new ASU did not have a material impact on our consolidated financial results.
Leases	We lease construction and office equipment, distribution facilities and office space. Leases with an initial term of 12 months or less, including month to month leases, are not recorded on the balance sheet. Lease expense for short-term leases is recognized on a straight line basis over the lease term. For lease agreements entered into or reassessed after the adoption of ASC 842, we combine lease and nonlease components. While we also own mineral leases for mining operations, those leases are outside the scope of ASC 842. Assets acquired under finance leases are included in property, plant and equipment. Many of our leases include options to purchase the leased equipment. The depreciable life of assets and leasehold improvements are limited by the expected lease term, unless there is a transfer of title or purchase option reasonably certain of exercise. Our lease agreements do not contain any material residual value guarantees or material restrictive covenants. We lease construction and office equipment, distribution facilities and office space. Leases with an initial term of 12 months or less, including month to month leases, are not recorded on the balance sheet. Lease expense for short-term leases is recognized on a straight line basis over the lease term. For lease agreements entered into or reassessed after the adoption of ASC 842, we combine lease and nonlease components. While we also own mineral leases for mining operations, those leases are outside the scope of ASC 842. Assets acquired under finance leases are included in property, plant and equipment. Many of our leases include options to purchase the leased equipment. The depreciable life of assets and leasehold improvements are limited by the expected lease term, unless there is a transfer of title or purchase option reasonably certain of exercise. Our lease agreements do not contain any material residual value guarantees or material restrictive covenants.
Summit Materials, LLC
Summary Of Significant Accounting Policies And Recent Accounting Pronouncements [Line Items]
Basis of Presentation	Basis of Presentation —These unaudited consolidated financial statements were prepared in accordance with U.S. generally accepted accounting principles (“U.S. GAAP”) for interim financial information, without audit, pursuant to the rules and regulations of the Securities and Exchange Commission (“SEC”). Certain information and footnote disclosures typically included in financial statements prepared in accordance with U.S. GAAP have been condensed or omitted pursuant to such rules and regulations. These unaudited consolidated financial statements should be read in conjunction with the Company’s audited consolidated financial statements and the notes thereto as of and for the year ended December 29, 2018 . The Company continues to follow the accounting policies set forth in those audited consolidated financial statements. Management believes that these consolidated interim financial statements include all adjustments, normal and recurring in nature, that are necessary to present fairly the financial position of the Company as of March 30, 2019 , the results of operations for the three months ended March 30, 2019 and March 31, 2018 and cash flows for the three months ended March 30, 2019 and March 31, 2018 .
Use of Estimates	Use of Estimates —Preparation of these consolidated financial statements in conformity with 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 23 U.S. states and in British Columbia, Canada, with the most significant revenue generated in Texas, Utah, Kansas 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 the three months ended March 30, 2019 or March 31, 2018 .
Revenue Recognition	Revenue Recognition —We earn revenue from the sale of products, which primarily include aggregates, cement, ready-mix concrete and asphalt, but also include concrete products and plastics components, and from the provision of services, which are primarily paving and related services, but also include landfill operations, the receipt and disposal of waste that is converted to fuel for use in our cement plants and underground storage space rental. Products We earn revenue from the sale of products, which primarily include aggregates, cement, ready-mix concrete and asphalt, but also include concrete products, net of discounts or allowances, if any, and freight and delivery charges billed to customers. Freight and delivery charges associated with cement sales are recorded on a net basis together with freight costs within cost of sales. Revenue for product sales is recognized when evidence of an arrangement exists and when control passes, which generally is when the product is shipped. Services We earn revenue from the provision of services, which are primarily paving and related services, but also include landfill operations, the receipt and disposal of waste that is converted to fuel for use in our cement plants, and underground storage space rental. Revenue from the receipt of waste fuels is recognized when the waste is accepted and a corresponding liability is recognized for the costs to process the waste into fuel for the manufacturing of cement or to ship the waste offsite for disposal in accordance with applicable regulations. Revenue derived from paving and related services is recognized using the percentage of completion method, which approximates progress towards completion. Under the percentage of completion method, we recognize paving and related services revenue as services are rendered. The majority of our construction service contracts are completed within one year, but may occasionally extend beyond this time frame. We estimate profit as the difference between total estimated revenue and total estimated cost of a contract and recognize that profit over the life of the contract based on input measures. We generally measure progress toward completion on long-term paving and related services contracts based on the proportion of costs incurred to date relative to total estimated costs at completion. We include revisions of estimated profits on contracts in earnings under the cumulative catch-up method, under which the effect of revisions in estimates is recognized immediately. If a revised estimate of contract profitability reveals an anticipated loss on the contract, we recognize the loss in the period it is identified. The percentage of completion method of accounting involves the use of various estimating techniques to project costs at completion, and in some cases includes estimates of recoveries asserted against the customer for changes in specifications or other disputes. Contract estimates involve various assumptions and projections relative to the outcome of future events over multiple periods, including future labor productivity and availability, the nature and complexity of the work to be performed, the cost and availability of materials, the effect of delayed performance, and the availability and timing of funding from the customer. These estimates are based on our best judgment. A significant change in one or more of these estimates could affect the profitability of one or more of our contracts. We review our contract estimates regularly to assess revisions in contract values and estimated costs at completion. 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. No material adjustments to a contract were recognized in the three months ended March 30, 2019 . 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 amounts were not billable under the contract terms at the balance sheet date. In accordance with the contract terms, the unbilled receivables at the balance sheet date are expected to be billed in following periods. Billings in excess of costs and estimated earnings represent billings in excess of revenue recognized. Contract assets and liabilities are netted on a contract-by-contract basis.
New Accounting Standards	New Accounting Standards — In February 2016, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2016-02, Leases (Topic 842), which will result in lessees recognizing most leases on the balance sheet. Lessees are required to disclose more quantitative and qualitative information about the leases than current U.S. GAAP requires. The ASU and subsequent amendments issued in 2018 are effective for public entities for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2018. We adopted the standard effective December 30, 2018 using the modified retrospective approach. The modified retrospective approach provides a method for recording existing leases at adoption. In addition, we elected the package of practical expedients permitted under the transition guidance within the new standard, which among other things, allowed us to carry forward the historical lease classification. In addition, we elected the hindsight practical expedient to determine the lease term for existing leases. The most significant impact upon adoption was the recognition of $36.8 million of operating lease right-of-use assets and $36.8 million operating lease liabilities. The standard had no material impact on our statement of cash flows. In August 2017, the FASB issued ASU No. 2017-12, Derivatives and Hedging (Topic 815): Targeted Improvements to Accounting for Hedging Activities, allowing more financial and nonfinancial hedging strategies to be eligible for hedge accounting. The ASU is effective for fiscal years beginning after December 15, 2018 and interim periods within those fiscal years. The adoption of this new ASU did not have a material impact on our consolidated financial results. In June 2018, the FASB issued ASU No. 2018-07, Compensation-Stock Compensation (Topic 718): Improvements to Nonemployee Share-Based Payment Accounting, increasing the scope of Topic 718 to include share-based payment transactions for acquiring goods and services from nonemployees. The ASU is effective for fiscal years beginning after December 15, 2018 and interim periods within those fiscal years. The adoption of this new ASU did not have a material impact on our consolidated financial results.

Goodwill and Intangibles - (Tab

Goodwill and Intangibles - (Tables)	3 Months Ended
	Mar. 30, 2019
Business Acquisition [Line Items]
Goodwill by Reportable Segment and in Total	Changes in the carrying amount of goodwill, by reportable segment, from December 29, 2018 to March 30, 2019 are summarized as follows: West East Cement Total Balance, December 29, 2018 $ 580,567 $ 406,805 $ 204,656 $ 1,192,028 Acquisitions (1) 1,143 879 — 2,022 Foreign currency translation adjustments 1,212 — — 1,212 Balance, March 30, 2019 $ 582,922 $ 407,684 $ 204,656 $ 1,195,262 _____________________________________________________________________________________________ (1) Reflects goodwill from 2019 acquisitions and working capital adjustments from prior year acquisitions.
Intangible Assets by Type and in Total	The following table shows intangible assets by type and in total: March 30, 2019 December 29, 2018 Gross Carrying Amount Accumulated Amortization Net Carrying Amount Gross Carrying Amount Accumulated Amortization Net Carrying Amount Mineral leases $ 19,064 $ (5,548 ) $ 13,516 $ 19,064 $ (5,259 ) $ 13,805 Reserve rights 6,234 (2,024 ) 4,210 6,234 (1,940 ) 4,294 Trade names 1,000 (883 ) 117 1,000 (858 ) 142 Other 409 (201 ) 208 409 (190 ) 219 Total intangible assets $ 26,707 $ (8,656 ) $ 18,051 $ 26,707 $ (8,247 ) $ 18,460
Estimated Amortization Expense for Intangible Assets	The estimated amortization expense for the intangible assets for each of the five years subsequent to March 30, 2019 is as follows: 2019 (nine months) $ 1,189 2020 1,510 2021 1,475 2022 1,482 2023 1,349 2024 1,254 Thereafter 9,792 Total $ 18,051
Summit Materials, LLC
Business Acquisition [Line Items]
Goodwill by Reportable Segment and in Total	Changes in the carrying amount of goodwill, by reportable segment, from December 29, 2018 to March 30, 2019 are summarized as follows: West East Cement Total Balance, December 29, 2018 $ 581,567 $ 406,805 $ 204,656 $ 1,193,028 Acquisitions (1) 1,143 879 — 2,022 Foreign currency translation adjustments 1,212 — — 1,212 Balance, March 30, 2019 $ 583,922 $ 407,684 $ 204,656 $ 1,196,262 _______________________________________________________________________ (1) Reflects goodwill from 2019 acquisitions and working capital adjustments from prior year acquisitions.
Intangible Assets by Type and in Total	The following table shows intangible assets by type and in total: March 30, 2019 December 29, 2018 Gross Carrying Amount Accumulated Amortization Net Carrying Amount Gross Carrying Amount Accumulated Amortization Net Carrying Amount Mineral leases $ 19,064 $ (5,548 ) $ 13,516 $ 19,064 $ (5,259 ) $ 13,805 Reserve rights 6,234 (2,024 ) 4,210 6,234 (1,940 ) 4,294 Trade names 1,000 (883 ) 117 1,000 (858 ) 142 Other 409 (201 ) 208 409 (190 ) 219 Total intangible assets $ 26,707 $ (8,656 ) $ 18,051 $ 26,707 $ (8,247 ) $ 18,460
Estimated Amortization Expense for Intangible Assets	The estimated amortization expense for the intangible assets for each of the five years subsequent to March 30, 2019 is as follows: 2019 (nine months) $ 1,189 2020 1,510 2021 1,475 2022 1,482 2023 1,349 2024 1,254 Thereafter 9,792 Total $ 18,051

Revenue Recognition (Tables)

Revenue Recognition (Tables)	3 Months Ended
	Mar. 30, 2019
Revenue from External Customer [Line Items]
Revenue by Product	Revenue by product for the three months ended March 30, 2019 and March 31, 2018 is as follows: Three months ended March 30, 2019 March 31, 2018 Revenue by product*: Aggregates $ 87,872 $ 67,450 Cement 32,499 33,117 Ready-mix concrete 117,320 122,015 Asphalt 23,038 18,141 Paving and related services 34,345 34,336 Other 37,565 39,362 Total revenue $ 332,639 $ 314,421 *Revenue from liquid asphalt terminals is included in asphalt revenue.
Schedule of Contract Asset and Liability	The following table outlines the significant changes in contract assets and contract liability balances from December 29, 2018 to March 30, 2019 . Also included in the table is the net change in estimate as a percentage of aggregate revenue for such contracts: Costs and estimated earnings in excess of billings Billings in excess of costs and estimated earnings Balance - December 29, 2018 $ 18,602 $ 11,840 Changes in revenue billed, contract price or cost estimates (1,541 ) (1,195 ) Other 18 11 Balance - March 30, 2019 $ 17,079 $ 10,656
Summary of Accounts Receivable, Net	Accounts receivable, net consisted of the following as of March 30, 2019 and December 29, 2018 : March 30, 2019 December 29, 2018 Trade accounts receivable $ 167,337 $ 157,601 Construction contract receivables 20,755 47,994 Retention receivables 12,902 15,010 Receivables from related parties 575 629 Accounts receivable 201,569 221,234 Less: Allowance for doubtful accounts (6,158 ) (6,716 ) Accounts receivable, net $ 195,411 $ 214,518
Summit Materials, LLC
Revenue from External Customer [Line Items]
Revenue by Product	Revenue by product for the three months ended March 30, 2019 and March 31, 2018 is as follows: Three months ended March 30, March 31, 2019 2018 Revenue by product*: Aggregates $ 87,872 $ 67,450 Cement 32,499 33,117 Ready-mix concrete 117,320 122,015 Asphalt 23,038 18,141 Paving and related services 34,345 34,336 Other 37,565 39,362 Total revenue $ 332,639 $ 314,421 *Revenue from liquid asphalt terminals is included in asphalt revenue.
Schedule of Contract Asset and Liability	The following table outlines the significant changes in contract assets and contract liability balances from December 29, 2018 to March 30, 2019 . Also included in the table is the net change in estimate as a percentage of aggregate revenue for such contracts: Costs and estimated Billings in excess earnings in of costs and excess of billings estimated earnings Balance - December 29, 2018 $ 18,602 $ 11,840 Changes in revenue billed, contract price or cost estimates (1,541 ) (1,195 ) Other 18 11 Balance - March 30, 2019 $ 17,079 $ 10,656
Summary of Accounts Receivable, Net	Accounts receivable, net consisted of the following as of March 30, 2019 and December 29, 2018 : March 30, December 29, 2019 2018 Trade accounts receivable $ 167,337 $ 157,601 Construction contract receivables 20,755 47,994 Retention receivables 12,902 15,010 Receivables from related parties 575 629 Accounts receivable 201,569 221,234 Less: Allowance for doubtful accounts (6,158 ) (6,716 ) Accounts receivable, net $ 195,411 $ 214,518

Inventories (Tables)

Inventories (Tables)	3 Months Ended
	Mar. 30, 2019
Inventory [Line Items]
Components of Inventories	Inventories consisted of the following as of March 30, 2019 and December 29, 2018 : March 30, 2019 December 29, 2018 Aggregate stockpiles $ 146,132 $ 151,300 Finished goods 35,275 34,993 Work in process 7,947 7,478 Raw materials 24,684 20,080 Total $ 214,038 $ 213,851
Summit Materials, LLC
Inventory [Line Items]
Components of Inventories	Inventories consisted of the following as of March 30, 2019 and December 29, 2018 : March 30, 2019 December 29, 2018 Aggregate stockpiles $ 146,132 $ 151,300 Finished goods 35,275 34,993 Work in process 7,947 7,478 Raw materials 24,684 20,080 Total $ 214,038 $ 213,851

Accrued Expenses (Tables)

Accrued Expenses (Tables)	3 Months Ended
	Mar. 30, 2019
Schedule Of Accrued Expenses [Line Items]
Components of Accrued Expenses	Accrued expenses consisted of the following as of March 30, 2019 and December 29, 2018 : March 30, 2019 December 29, 2018 Interest $ 14,553 $ 26,223 Payroll and benefits 19,126 15,952 Finance lease obligations 17,407 15,557 Insurance 16,071 13,625 Non-income taxes 9,876 7,442 Professional fees 625 1,408 Other (1) 18,818 20,284 Total $ 96,476 $ 100,491 (1) Consists primarily of subcontractor and working capital settlement accruals.
Summit Materials, LLC
Schedule Of Accrued Expenses [Line Items]
Components of Accrued Expenses	Accrued expenses consisted of the following as of March 30, 2019 and December 29, 2018 : March 30, 2019 December 29, 2018 Interest $ 14,553 $ 26,223 Payroll and benefits 19,126 15,952 Finance lease obligations 17,407 15,557 Insurance 16,071 13,625 Non-income taxes 10,107 7,674 Professional fees 625 1,408 Other (1) 18,818 19,590 Total $ 96,707 $ 100,029 _______________________________________________________________________ (1) Consists primarily of subcontractor and working capital settlement accruals.

Debt (Tables)

Debt (Tables)	3 Months Ended
	Mar. 30, 2019
Debt Instrument [Line Items]
Schedule of Debt	Debt consisted of the following as of March 30, 2019 and December 29, 2018 : March 30, 2019 December 29, 2018 Term Loan, due 2024: $627.4 million and $630.6 million, net of $1.3 million and $1.3 million discount at March 30, 2019 and December 29, 2018, respectively $ 626,147 $ 629,268 8 1 ⁄ 2 % Senior Notes, due 2022 — 250,000 6 1 ⁄ 8 % Senior Notes, due 2023: $650.0 million, net of $1.0 million and $1.1 million discount at March 30, 2019 and December 29, 2018, respectively 648,952 648,891 5 1 ⁄ 8 % Senior Notes, due 2025 300,000 300,000 6 1 ⁄ 2 % Senior Notes, due 2027 300,000 — Total 1,875,099 1,828,159 Current portion of long-term debt 4,765 6,354 Long-term debt $ 1,870,334 $ 1,821,805
Schedule of Contractual Payments of Long-Term Debt	The contractual payments of long-term debt, including current maturities, for the five years subsequent to March 30, 2019 , are as follows: 2019 (nine months) $ 3,177 2020 7,942 2021 6,354 2022 6,354 2023 656,354 2024 597,253 Thereafter 600,000 Total 1,877,434 Less: Original issue net discount (2,335 ) Less: Capitalized loan costs (14,988 ) Total debt $ 1,860,111
Summary of Activity for Deferred Financing Fees	The following table presents the activity for the deferred financing fees for the three months ended March 30, 2019 and March 31, 2018 : Deferred financing fees Balance—December 29, 2018 $ 15,475 Loan origination fees 5,774 Amortization (998 ) Write off of deferred financing fees (2,851 ) Balance—March 30, 2019 $ 17,400 Balance - December 30, 2017 $ 19,033 Amortization (1,013 ) Balance - March 31, 2018 $ 18,020
Summit Materials, LLC
Debt Instrument [Line Items]
Schedule of Debt	Debt consisted of the following as of March 30, 2019 and December 29, 2018 : March 30, 2019 December 29, 2018 Term Loan, due 2024: $627.4 million and $630.6 million, net of $1.3 million and $1.3 million discount at March 30, 2019 and December 29, 2018, respectively $ 626,147 $ 629,268 8 1/2 % Senior Notes, due 2022 — 250,000 6 1/8 % Senior Notes, due 2023: $650.0 million, net of $1.0 million and $1.1 million discount at March 30, 2019 and December 29, 2018, respectively 648,952 648,891 5 1⁄8 % Senior Notes, due 2025 300,000 300,000 6 1⁄2 % Senior Notes, due 2027 300,000 — Total 1,875,099 1,828,159 Current portion of long-term debt 4,765 6,354 Long-term debt $ 1,870,334 $ 1,821,805
Schedule of Contractual Payments of Long-Term Debt	The contractual payments of long-term debt, including current maturities, for the five years subsequent to March 30, 2019 , are as follows: 2019 (nine months) $ 3,177 2020 7,942 2021 6,354 2022 6,354 2023 656,354 2024 597,253 Thereafter 600,000 Total 1,877,434 Less: Original issue net discount (2,335 ) Less: Capitalized loan costs (14,988 ) Total debt $ 1,860,111
Summary of Activity for Deferred Financing Fees	The following table presents the activity for the deferred financing fees for the three months ended March 30, 2019 and March 31, 2018 : Deferred financing fees Balance—December 29, 2018 $ 15,475 Loan origination fees 5,774 Amortization (998 ) Write off of deferred financing fees (2,851 ) Balance—March 30, 2019 $ 17,400 Balance - December 30, 2017 $ 19,033 Amortization (1,013 ) Balance - March 31, 2018 $ 18,020

Earnings Per Share (Tables)

Earnings Per Share (Tables)	3 Months Ended
	Mar. 30, 2019
Earnings Per Share [Abstract]
Schedule of Basic Earnings Per Share	The following table shows the calculation of basic and diluted loss per share: Three months ended March 30, 2019 March 31, 2018 Net loss attributable to Summit Inc. $ (68,772 ) $ (53,729 ) Weighted average shares of Class A stock outstanding 111,811,679 110,659,098 Basic and diluted loss per share $ (0.62 ) $ (0.49 )
Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share	Excluded from the above calculations were the shares noted below as they were antidilutive: Three months ended March 30, 2019 March 31, 2018 Antidilutive shares: LP Units 3,418,018 3,585,516 Time-vesting stock options 3,192,674 3,296,133 Warrants 100,037 100,037 Time-vesting restricted stock units 1,589,396 854,482 Market-based restricted stock units 419,247 295,252

Stockholders' Equity_Members'_2

Stockholders' Equity/Members' Interest (Tables)	3 Months Ended
	Mar. 30, 2019
Schedule of Capitalization, Equity [Line Items]
Schedule of changes in ownership of Summit Holdings	The following table summarizes the changes in our ownership of Summit Holdings: Summit Inc. LP Units Total Summit Inc. Balance — December 29, 2018 111,658,927 3,435,518 115,094,445 97.0 % Exchanges during period 17,500 (17,500 ) — Other equity transactions 391,104 — 391,104 Balance — March 30, 2019 112,067,531 3,418,018 115,485,549 97.0 % Balance — December 30, 2017 110,350,594 3,689,620 114,040,214 96.8 % Exchanges during period 104,104 (104,104 ) — Other equity transactions 1,033,875 — 1,033,875 Balance — March 31, 2018 111,488,573 3,585,516 115,074,089 96.9 %
Schedule of Changes in Each Component of Accumulated Other Comprehensive Income (Loss)	The changes in each component of accumulated other comprehensive income (loss) consisted of the following: Change in retirement plans Foreign currency translation adjustments Cash flow hedge adjustments Accumulated other comprehensive income (loss) Balance — December 29, 2018 $ 3,573 $ (2,147 ) $ 1,255 $ 2,681 Foreign currency translation adjustment, net of tax — 1,704 — 1,704 Loss on cash flow hedges, net of tax — — (120 ) (120 ) Balance — March 30, 2019 $ 3,573 $ (443 ) $ 1,135 $ 4,265 Balance — December 30, 2017 $ 2,364 $ 4,637 $ 385 $ 7,386 Foreign currency translation adjustment, net of tax — (3,772 ) — (3,772 ) Income on cash flow hedges, net of tax — — 1,209 1,209 Balance — March 31, 2018 $ 2,364 $ 865 $ 1,594 $ 4,823
Summit Materials, LLC
Schedule of Capitalization, Equity [Line Items]
Schedule of Changes in Each Component of 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 29, 2018 $ (4,392 ) $ (19,370 ) $ 146 $ (23,616 ) Foreign currency translation adjustment — 2,358 — 2,358 Loss on cash flow hedges — — (166 ) (166 ) Balance — March 30, 2019 $ (4,392 ) $ (17,012 ) $ (20 ) $ (21,424 ) Balance - December 30, 2017 $ (7,181 ) $ (17,790 ) $ (2,473 ) $ (27,444 ) Foreign currency translation adjustment — 706 — 706 Income on cash flow hedges — — 412 412 Balance - March 31, 2018 $ (7,181 ) $ (17,084 ) $ (2,061 ) $ (26,326 )

Supplemental Cash Flow Inform_2

Supplemental Cash Flow Information (Tables)	3 Months Ended
	Mar. 30, 2019
Schedule Of Cash Flow Supplemental [Line Items]
Schedule of Supplemental Cash Flow Information	Supplemental cash flow information is as follows: Three months ended March 30, 2019 March 31, 2018 Cash payments: Interest $ 21,126 $ 26,927 Income (refund) taxes (20 ) 1,582 Operating cash payments on operating leases 2,837 — Operating cash payments on finance leases 699 — Finance cash payments on finance leases 2,580 — Non cash financing activities: Right of use assets obtained in exchange for operating lease obligations $ 1,608 $ — Right of use assets obtained in exchange for finance leases obligations 9,442 — Exchange of LP Units to shares of Class A common stock 277 3,325
Summit Materials, LLC
Schedule Of Cash Flow Supplemental [Line Items]
Schedule of Supplemental Cash Flow Information	Supplemental cash flow information is as follows: Three months ended March 30, 2019 March 31, 2018 Cash payments: Interest $ 21,126 $ 26,927 Income (refund) taxes (20 ) 1,582 Operating cash payments on operating leases 2,837 — Operating cash payments on finance leases 699 — Finance cash payments on finance leases 2,580 — Non cash financing activities: Right of use assets obtained in exchange for operating lease obligations $ 1,608 $ — Right of use assets obtained in exchange for finance leases obligations 9,442 —

Leases - (Tables)

Leases - (Tables)	3 Months Ended
	Mar. 30, 2019
Lessee, Lease, Description [Line Items]
Schedule of Lease Cost	The components of lease expense were as follows: March 30, 2019 Operating lease cost $ 2,455 Variable lease cost 72 Short-term lease cost 6,581 Financing lease cost: Amortization of right-of-use assets 2,623 Interest on lease liabilities 755 Total lease cost $ 12,486 Supplemental balance sheet information related to leases: Operating leases: Operating lease right-of-use assets $ 34,403 Current operating lease liabilities $ 8,098 Noncurrent operating lease liabilities 27,200 Total operating lease liabilities $ 35,298 Finance leases: Property and equipment, gross $ 75,132 Less accumulated depreciation (20,581 ) Property and equipment, net $ 54,551 Current finance lease liabilities $ 17,407 Long-term finance lease liabilities 37,851 Total finance lease liabilities $ 55,258 March 30, 2019 Lease Term Discount Rate (years) (%) Weighted average: Operating leases 7.9 5.6 % Finance lease 2.8 5.3 % Maturities of lease liabilities were as follows: Operating Leases Finance Leases 2019 (nine months) $ 7,228 $ 15,217 2020 8,737 15,703 2021 7,138 17,974 2022 4,370 6,556 2023 3,419 1,509 2024 2,235 1,750 Thereafter 11,212 2,667 Total lease payments 44,339 61,376 Less imputed interest (9,041 ) (6,118 ) Present value of lease payments $ 35,298 $ 55,258
Schedule of Lease Assets and Liabilities	The components of lease expense were as follows: March 30, 2019 Operating lease cost $ 2,455 Variable lease cost 72 Short-term lease cost 6,581 Financing lease cost: Amortization of right-of-use assets 2,623 Interest on lease liabilities 755 Total lease cost $ 12,486 Supplemental balance sheet information related to leases: Operating leases: Operating lease right-of-use assets $ 34,403 Current operating lease liabilities $ 8,098 Noncurrent operating lease liabilities 27,200 Total operating lease liabilities $ 35,298 Finance leases: Property and equipment, gross $ 75,132 Less accumulated depreciation (20,581 ) Property and equipment, net $ 54,551 Current finance lease liabilities $ 17,407 Long-term finance lease liabilities 37,851 Total finance lease liabilities $ 55,258 March 30, 2019 Lease Term Discount Rate (years) (%) Weighted average: Operating leases 7.9 5.6 % Finance lease 2.8 5.3 % Maturities of lease liabilities were as follows: Operating Leases Finance Leases 2019 (nine months) $ 7,228 $ 15,217 2020 8,737 15,703 2021 7,138 17,974 2022 4,370 6,556 2023 3,419 1,509 2024 2,235 1,750 Thereafter 11,212 2,667 Total lease payments 44,339 61,376 Less imputed interest (9,041 ) (6,118 ) Present value of lease payments $ 35,298 $ 55,258 As previously disclosed, our future minimum lease payment obligations as of December 29, 2018 were as follows: Operating Leases 2019 $ 9,479 2020 8,101 2021 6,701 2022 4,279 2023 3,411
Schedule of Finance Lease Liability Maturities	The components of lease expense were as follows: March 30, 2019 Operating lease cost $ 2,455 Variable lease cost 72 Short-term lease cost 6,581 Financing lease cost: Amortization of right-of-use assets 2,623 Interest on lease liabilities 755 Total lease cost $ 12,486 Supplemental balance sheet information related to leases: Operating leases: Operating lease right-of-use assets $ 34,403 Current operating lease liabilities $ 8,098 Noncurrent operating lease liabilities 27,200 Total operating lease liabilities $ 35,298 Finance leases: Property and equipment, gross $ 75,132 Less accumulated depreciation (20,581 ) Property and equipment, net $ 54,551 Current finance lease liabilities $ 17,407 Long-term finance lease liabilities 37,851 Total finance lease liabilities $ 55,258 March 30, 2019 Lease Term Discount Rate (years) (%) Weighted average: Operating leases 7.9 5.6 % Finance lease 2.8 5.3 % Maturities of lease liabilities were as follows: Operating Leases Finance Leases 2019 (nine months) $ 7,228 $ 15,217 2020 8,737 15,703 2021 7,138 17,974 2022 4,370 6,556 2023 3,419 1,509 2024 2,235 1,750 Thereafter 11,212 2,667 Total lease payments 44,339 61,376 Less imputed interest (9,041 ) (6,118 ) Present value of lease payments $ 35,298 $ 55,258
Schedule of Operating Lease Liability Maturities	The components of lease expense were as follows: March 30, 2019 Operating lease cost $ 2,455 Variable lease cost 72 Short-term lease cost 6,581 Financing lease cost: Amortization of right-of-use assets 2,623 Interest on lease liabilities 755 Total lease cost $ 12,486 Supplemental balance sheet information related to leases: Operating leases: Operating lease right-of-use assets $ 34,403 Current operating lease liabilities $ 8,098 Noncurrent operating lease liabilities 27,200 Total operating lease liabilities $ 35,298 Finance leases: Property and equipment, gross $ 75,132 Less accumulated depreciation (20,581 ) Property and equipment, net $ 54,551 Current finance lease liabilities $ 17,407 Long-term finance lease liabilities 37,851 Total finance lease liabilities $ 55,258 March 30, 2019 Lease Term Discount Rate (years) (%) Weighted average: Operating leases 7.9 5.6 % Finance lease 2.8 5.3 % Maturities of lease liabilities were as follows: Operating Leases Finance Leases 2019 (nine months) $ 7,228 $ 15,217 2020 8,737 15,703 2021 7,138 17,974 2022 4,370 6,556 2023 3,419 1,509 2024 2,235 1,750 Thereafter 11,212 2,667 Total lease payments 44,339 61,376 Less imputed interest (9,041 ) (6,118 ) Present value of lease payments $ 35,298 $ 55,258
Schedule of Future Minimum Rental Payments for Operating Leases	As previously disclosed, our future minimum lease payment obligations as of December 29, 2018 were as follows: Operating Leases 2019 $ 9,479 2020 8,101 2021 6,701 2022 4,279 2023 3,411
Summit Materials, LLC
Lessee, Lease, Description [Line Items]
Schedule of Lease Cost	The components of lease expense were as follows: March 30, 2019 Operating lease cost $ 2,455 Variable lease cost 72 Short-term lease cost 6,581 Financing lease cost: Amortization of right-of-use assets 2,623 Interest on lease liabilities 755 Total lease cost $ 12,486 Supplemental balance sheet information related to leases: Operating leases: Operating lease right-of-use assets $ 34,403 Current operating lease liabilities $ 8,098 Noncurrent operating lease liabilities 27,200 Total operating lease liabilities $ 35,298 Finance leases: Property and equipment, gross $ 75,132 Less accumulated depreciation (20,581 ) Property and equipment, net $ 54,551 Current finance lease liabilities $ 17,407 Long-term finance lease liabilities 37,851 Total finance lease liabilities $ 55,258 March 30, 2019 Lease Term Discount Rate (years) (%) Weighted average: Operating leases 7.9 5.6 % Finance lease 2.8 5.3 % Maturities of lease liabilities were as follows: Operating Leases Finance Leases 2019 (nine months) $ 7,228 $ 15,217 2020 8,737 15,703 2021 7,138 17,974 2022 4,370 6,556 2023 3,419 1,509 2024 2,235 1,750 Thereafter 11,212 2,667 Total lease payments 44,339 61,376 Less imputed interest (9,041 ) (6,118 ) Present value of lease payments $ 35,298 $ 55,258 As previously disclosed, our future minimum lease payment obligations as of December 29, 2018 were as follows: Operating Leases 2019 $ 9,479 2020 8,101 2021 6,701 2022 4,279 2023 3,411
Schedule of Lease Assets and Liabilities	The components of lease expense were as follows: March 30, 2019 Operating lease cost $ 2,455 Variable lease cost 72 Short-term lease cost 6,581 Financing lease cost: Amortization of right-of-use assets 2,623 Interest on lease liabilities 755 Total lease cost $ 12,486 Supplemental balance sheet information related to leases: Operating leases: Operating lease right-of-use assets $ 34,403 Current operating lease liabilities $ 8,098 Noncurrent operating lease liabilities 27,200 Total operating lease liabilities $ 35,298 Finance leases: Property and equipment, gross $ 75,132 Less accumulated depreciation (20,581 ) Property and equipment, net $ 54,551 Current finance lease liabilities $ 17,407 Long-term finance lease liabilities 37,851 Total finance lease liabilities $ 55,258 March 30, 2019 Lease Term Discount Rate (years) (%) Weighted average: Operating leases 7.9 5.6 % Finance lease 2.8 5.3 % Maturities of lease liabilities were as follows: Operating Leases Finance Leases 2019 (nine months) $ 7,228 $ 15,217 2020 8,737 15,703 2021 7,138 17,974 2022 4,370 6,556 2023 3,419 1,509 2024 2,235 1,750 Thereafter 11,212 2,667 Total lease payments 44,339 61,376 Less imputed interest (9,041 ) (6,118 ) Present value of lease payments $ 35,298 $ 55,258
Schedule of Finance Lease Liability Maturities	The components of lease expense were as follows: March 30, 2019 Operating lease cost $ 2,455 Variable lease cost 72 Short-term lease cost 6,581 Financing lease cost: Amortization of right-of-use assets 2,623 Interest on lease liabilities 755 Total lease cost $ 12,486 Supplemental balance sheet information related to leases: Operating leases: Operating lease right-of-use assets $ 34,403 Current operating lease liabilities $ 8,098 Noncurrent operating lease liabilities 27,200 Total operating lease liabilities $ 35,298 Finance leases: Property and equipment, gross $ 75,132 Less accumulated depreciation (20,581 ) Property and equipment, net $ 54,551 Current finance lease liabilities $ 17,407 Long-term finance lease liabilities 37,851 Total finance lease liabilities $ 55,258 March 30, 2019 Lease Term Discount Rate (years) (%) Weighted average: Operating leases 7.9 5.6 % Finance lease 2.8 5.3 % Maturities of lease liabilities were as follows: Operating Leases Finance Leases 2019 (nine months) $ 7,228 $ 15,217 2020 8,737 15,703 2021 7,138 17,974 2022 4,370 6,556 2023 3,419 1,509 2024 2,235 1,750 Thereafter 11,212 2,667 Total lease payments 44,339 61,376 Less imputed interest (9,041 ) (6,118 ) Present value of lease payments $ 35,298 $ 55,258
Schedule of Operating Lease Liability Maturities	The components of lease expense were as follows: March 30, 2019 Operating lease cost $ 2,455 Variable lease cost 72 Short-term lease cost 6,581 Financing lease cost: Amortization of right-of-use assets 2,623 Interest on lease liabilities 755 Total lease cost $ 12,486 Supplemental balance sheet information related to leases: Operating leases: Operating lease right-of-use assets $ 34,403 Current operating lease liabilities $ 8,098 Noncurrent operating lease liabilities 27,200 Total operating lease liabilities $ 35,298 Finance leases: Property and equipment, gross $ 75,132 Less accumulated depreciation (20,581 ) Property and equipment, net $ 54,551 Current finance lease liabilities $ 17,407 Long-term finance lease liabilities 37,851 Total finance lease liabilities $ 55,258 March 30, 2019 Lease Term Discount Rate (years) (%) Weighted average: Operating leases 7.9 5.6 % Finance lease 2.8 5.3 % Maturities of lease liabilities were as follows: Operating Leases Finance Leases 2019 (nine months) $ 7,228 $ 15,217 2020 8,737 15,703 2021 7,138 17,974 2022 4,370 6,556 2023 3,419 1,509 2024 2,235 1,750 Thereafter 11,212 2,667 Total lease payments 44,339 61,376 Less imputed interest (9,041 ) (6,118 ) Present value of lease payments $ 35,298 $ 55,258

Fair Value (Tables)

Fair Value (Tables)	3 Months Ended
	Mar. 30, 2019
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Schedule of Contingent Consideration and Derivatives Measured at Fair Value	The fair value of contingent consideration and derivatives as of March 30, 2019 and December 29, 2018 was: March 30, 2019 December 29, 2018 Current portion of acquisition-related liabilities and Accrued expenses: Contingent consideration $ 4,568 $ 1,394 Cash flow hedges — — Acquisition-related liabilities and Other noncurrent liabilities: Contingent consideration $ 1,205 $ 5,175 Cash flow hedges — —
Schedule of Carrying Value and Fair Value of Financial Instruments	The carrying value and fair value of these financial instruments as of March 30, 2019 and December 29, 2018 was: March 30, 2019 December 29, 2018 Fair Value Carrying Value Fair Value Carrying Value Level 2 Long-term debt(1) $ 1,865,816 $ 1,875,099 $ 1,777,722 $ 1,828,159 Level 3 Current portion of deferred consideration and noncompete obligations(2) 32,854 32,854 32,876 32,876 Long term portion of deferred consideration and noncompete obligations(3) 37,703 37,703 44,293 44,293 (1) $4.8 million and $6.4 million were included in current portion of debt as of March 30, 2019 and December 29, 2018 , respectively. (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
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Schedule of Contingent Consideration and Derivatives Measured at Fair Value	The fair value of contingent consideration and derivatives as of March 30, 2019 and December 29, 2018 was: March 30, 2019 December 29, 2018 Current portion of acquisition-related liabilities and Accrued expenses: Contingent consideration $ 4,568 $ 1,394 Cash flow hedges — — Acquisition-related liabilities and Other noncurrent liabilities: Contingent consideration $ 1,205 $ 5,175 Cash flow hedges — —
Schedule of Carrying Value and Fair Value of Financial Instruments	The carrying value and fair value of these financial instruments as of March 30, 2019 and December 29, 2018 was: March 30, 2019 December 29, 2018 Fair Value Carrying Value Fair Value Carrying Value Level 2 Long-term debt(1) $ 1,865,816 $ 1,875,099 $ 1,777,722 $ 1,828,159 Level 3 Current portion of deferred consideration and noncompete obligations(2) 30,354 30,354 30,376 30,376 Long term portion of deferred consideration and noncompete obligations(3) 35,921 35,921 40,179 40,179 (1) $4.8 million and $6.4 million were included in current portion of debt as of March 30, 2019 and December 29, 2018 , respectively. (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.

Segment Information (Tables)

Segment Information (Tables)	3 Months Ended
	Mar. 30, 2019
Segment Reporting Information [Line Items]
Summary of Financial Data for Company's Reportable Business Segments	The following tables display selected financial data for the Company’s reportable business segments as of March 30, 2019 and December 29, 2018 and for the three months ended March 30, 2019 and March 31, 2018 : Three months ended March 30, 2019 March 31, 2018 Revenue*: West $ 181,945 $ 181,713 East 113,388 95,157 Cement 37,306 37,551 Total revenue $ 332,639 $ 314,421 *Intercompany sales are immaterial and the presentation above only reflects sales to external customers. Three months ended March 30, 2019 March 31, 2018 Loss from operations before taxes $ (99,538 ) $ (72,654 ) Interest expense 30,105 28,784 Depreciation, depletion and amortization 54,807 46,543 Accretion 581 415 Loss on debt financings 14,565 — Transaction costs 308 1,266 Non-cash compensation 5,906 8,507 Other (146 ) (7,348 ) Total Adjusted EBITDA $ 6,588 $ 5,513 Total Adjusted EBITDA by Segment: West $ 14,298 $ 16,173 East 3,242 (3,203 ) Cement (2,587 ) 3,667 Corporate and other (8,365 ) (11,124 ) Total Adjusted EBITDA $ 6,588 $ 5,513 Three months ended March 30, 2019 March 31, 2018 Purchases of property, plant and equipment West $ 30,375 $ 28,909 East 24,428 14,464 Cement 6,893 4,468 Total reportable segments 61,696 47,841 Corporate and other 492 1,664 Total purchases of property, plant and equipment $ 62,188 $ 49,505 Three months ended March 30, 2019 March 31, 2018 Depreciation, depletion, amortization and accretion: West $ 23,925 $ 22,151 East 20,211 17,727 Cement 10,300 6,370 Total reportable segments 54,436 46,248 Corporate and other 952 710 Total depreciation, depletion, amortization and accretion $ 55,388 $ 46,958 March 30, 2019 December 29, 2018 Total assets: West $ 1,379,580 $ 1,370,501 East 1,269,669 1,253,640 Cement 875,966 877,586 Total reportable segments 3,525,215 3,501,727 Corporate and other 336,146 355,914 Total $ 3,861,361 $ 3,857,641
Summit Materials, LLC
Segment Reporting Information [Line Items]
Summary of Financial Data for Company's Reportable Business Segments	The following tables display selected financial data for the Company’s reportable business segments as of March 30, 2019 and December 29, 2018 and for the three months ended March 30, 2019 and March 31, 2018 : Three months ended March 30, March 31, 2019 2018 Revenue*: West $ 181,945 $ 181,713 East 113,388 95,157 Cement 37,306 37,551 Total revenue $ 332,639 $ 314,421 *Intercompany sales are immaterial and the presentation above only reflects sales to external customers. Three months ended March 30, March 31, 2019 2018 Loss from operations before taxes $ (99,370 ) $ (72,440 ) Interest expense 29,937 28,570 Depreciation, depletion and amortization 54,807 46,543 Accretion 581 415 Loss on debt financings 14,565 — Transaction costs 308 1,266 Non-cash compensation 5,906 8,507 Other (146 ) (7,348 ) Total Adjusted EBITDA $ 6,588 $ 5,513 Total Adjusted EBITDA by Segment: West $ 14,298 $ 16,173 East 3,242 (3,203 ) Cement (2,587 ) 3,667 Corporate and other (8,365 ) (11,124 ) Total Adjusted EBITDA $ 6,588 $ 5,513 Three months ended March 30, 2019 March 31, 2018 Purchases of property, plant and equipment West $ 30,375 $ 28,909 East 24,428 14,464 Cement 6,893 4,468 Total reportable segments 61,696 47,841 Corporate and other 492 1,664 Total purchases of property, plant and equipment $ 62,188 $ 49,505 Three months ended March 30, March 31, 2019 2018 Depreciation, depletion, amortization and accretion: West $ 23,925 $ 22,151 East 20,211 17,727 Cement 10,300 6,370 Total reportable segments 54,436 46,248 Corporate and other 952 710 Total depreciation, depletion, amortization and accretion $ 55,388 $ 46,958 March 30, 2019 December 29, 2018 Total assets: West $ 1,379,580 $ 1,370,501 East 1,269,669 1,253,640 Cement 875,966 877,586 Total reportable segments 3,525,215 3,501,727 Corporate and other 84,042 131,517 Total $ 3,609,257 $ 3,633,244

Guarantor and Non-Guarantor F_2

Guarantor and Non-Guarantor Financial Information (Tables) - Summit Materials, LLC	3 Months Ended
	Mar. 30, 2019
Condensed Consolidating Balance Sheets	Condensed Consolidating Balance Sheets March 30, 2019 100% Owned Non- Issuers Guarantors Guarantors Eliminations Consolidated Assets Current assets: Cash and cash equivalents $ 69,094 $ 1,327 $ 3,733 $ (9,317 ) $ 64,837 Accounts receivable, net 9 182,644 12,934 (176 ) 195,411 Intercompany receivables 480,922 601,070 — (1,081,992 ) — Cost and estimated earnings in excess of billings — 15,609 1,470 — 17,079 Inventories — 210,662 3,376 — 214,038 Other current assets 1,963 13,908 3,374 — 19,245 Total current assets 551,988 1,025,220 24,887 (1,091,485 ) 510,610 Property, plant and equipment, net 12,817 1,727,295 59,829 — 1,799,941 Goodwill — 1,138,807 57,455 — 1,196,262 Intangible assets, net — 18,051 — — 18,051 Operating lease right-of-use assets 3,819 25,004 5,580 — 34,403 Other assets 3,270,321 153,303 1,005 (3,374,639 ) 49,990 Total assets $ 3,838,945 $ 4,087,680 $ 148,756 $ (4,466,124 ) $ 3,609,257 Liabilities and Member’s Interest Current liabilities: Current portion of debt $ 4,765 $ — $ — $ — $ 4,765 Current portion of acquisition-related liabilities — 34,922 — — 34,922 Accounts payable 2,435 92,173 8,022 (176 ) 102,454 Accrued expenses 37,556 66,582 1,886 (9,317 ) 96,707 Current operating lease liabilities 721 6,365 1,012 — 8,098 Intercompany payables 630,962 434,273 16,757 (1,081,992 ) — Billings in excess of costs and estimated earnings — 10,129 527 — 10,656 Total current liabilities 676,439 644,444 28,204 (1,091,485 ) 257,602 Long-term debt 1,855,346 — — — 1,855,346 Acquisition-related liabilities — 37,126 — — 37,126 Noncurrent operating lease liabilities 4,058 18,777 4,365 — 27,200 Other noncurrent liabilities 3,372 222,786 77,412 (171,317 ) 132,253 Total liabilities 2,539,215 923,133 109,981 (1,262,802 ) 2,309,527 Total member's interest 1,299,730 3,164,547 38,775 (3,203,322 ) 1,299,730 Total liabilities and member’s interest $ 3,838,945 $ 4,087,680 $ 148,756 $ (4,466,124 ) $ 3,609,257 Condensed Consolidating Balance Sheets December 29, 2018 100% Owned Non- Issuers Guarantors Guarantors Eliminations Consolidated Assets Current assets: Cash and cash equivalents $ 117,219 $ 8,440 $ 7,719 $ (4,870 ) $ 128,508 Accounts receivable, net — 199,538 15,165 (185 ) 214,518 Intercompany receivables 500,765 624,427 — (1,125,192 ) — Cost and estimated earnings in excess of billings — 17,711 891 — 18,602 Inventories — 210,149 3,702 — 213,851 Other current assets 1,953 11,308 2,800 — 16,061 Total current assets 619,937 1,071,573 30,277 (1,130,247 ) 591,540 Property, plant and equipment, net 13,300 1,709,083 57,749 — 1,780,132 Goodwill — 1,136,785 56,243 — 1,193,028 Intangible assets, net — 18,460 — — 18,460 Other assets 3,292,851 154,080 947 (3,397,794 ) 50,084 Total assets $ 3,926,088 $ 4,089,981 $ 145,216 $ (4,528,041 ) $ 3,633,244 Liabilities and Member’s Interest Current liabilities: Current portion of debt $ 6,354 $ — $ — $ — $ 6,354 Current portion of acquisition-related liabilities — 31,770 — — 31,770 Accounts payable 4,712 92,132 12,349 (185 ) 109,008 Accrued expenses 45,146 57,826 1,927 (4,870 ) 100,029 Intercompany payables 673,175 436,564 15,453 (1,125,192 ) — Billings in excess of costs and estimated earnings — 11,347 493 — 11,840 Total current liabilities 729,387 629,639 30,222 (1,130,247 ) 259,001 Long-term debt 1,807,502 — — — 1,807,502 Acquisition-related liabilities — 45,354 — — 45,354 Other noncurrent liabilities 3,768 226,137 77,368 (171,317 ) 135,956 Total liabilities 2,540,657 901,130 107,590 (1,301,564 ) 2,247,813 Total member's interest 1,385,431 3,188,851 37,626 (3,226,477 ) 1,385,431 Total liabilities and member’s interest $ 3,926,088 $ 4,089,981 $ 145,216 $ (4,528,041 ) $ 3,633,244
Condensed Consolidating Statements of Operations and Comprehensive Loss	Condensed Consolidating Statements of Operations For the three months ended March 30, 2019 100% Owned Non- Issuers Guarantors Guarantors Eliminations Consolidated Revenue $ — $ 318,181 $ 15,641 $ (1,183 ) $ 332,639 Cost of revenue (excluding items shown separately below) — 256,166 12,021 (1,183 ) 267,004 General and administrative expenses 14,930 50,032 2,956 — 67,918 Depreciation, depletion, amortization and accretion 952 52,920 1,516 — 55,388 Operating (loss) income (15,882 ) (40,937 ) (852 ) — (57,671 ) Other (income) loss, net 43,611 (1,942 ) (403 ) (29,504 ) 11,762 Interest expense (income) 31,697 (2,964 ) 1,204 — 29,937 Gain on sale of business — — — — — Income from operations before taxes (91,190 ) (36,031 ) (1,653 ) 29,504 (99,370 ) Income tax expense 374 (7,737 ) (443 ) — (7,806 ) Net income attributable to member of Summit Materials, LLC $ (91,564 ) $ (28,294 ) $ (1,210 ) $ 29,504 $ (91,564 ) Comprehensive income attributable to member of Summit Materials, LLC $ (89,372 ) $ (28,128 ) $ (3,568 ) $ 31,696 $ (89,372 ) Condensed Consolidating Statements of Operations For the three months ended March 31, 2018 100% Owned Non- Issuers Guarantors Guarantors Eliminations Consolidated Revenue $ — $ 300,658 $ 15,181 $ (1,418 ) $ 314,421 Cost of revenue (excluding items shown separately below) — 238,127 11,152 (1,418 ) 247,861 General and administrative expenses 20,947 47,177 3,003 — 71,127 Depreciation, depletion, amortization and accretion 710 44,993 1,255 — 46,958 Operating (loss) income (21,657 ) (29,639 ) (229 ) — (51,525 ) Other income, net 17,365 (6,858 ) 51 (18,213 ) (7,655 ) Interest expense (income) 29,582 (2,203 ) 1,191 — 28,570 Income from operations before taxes (68,604 ) (20,578 ) (1,471 ) 18,213 (72,440 ) Income tax expense (benefit) (8 ) (3,454 ) (382 ) — (3,844 ) Net income attributable to member of Summit Materials, LLC $ (68,596 ) $ (17,124 ) $ (1,089 ) $ 18,213 $ (68,596 ) Comprehensive income (loss) attributable to member of Summit Materials, LLC $ (70,705 ) $ (18,119 ) $ 2,015 $ 16,104 $ (70,705 )
Condensed Consolidating Statements of Cash Flows	Condensed Consolidating Statements of Cash Flows For the three months ended March 30, 2019 100% Owned Non- Issuers Guarantors Guarantors Eliminations Consolidated Net cash (used in) provided by operating activities $ (57,399 ) $ 26,570 $ 153 $ — $ (30,676 ) Cash flow from investing activities: Acquisitions, net of cash acquired — (2,842 ) — — (2,842 ) Purchase of property, plant and equipment (492 ) (57,326 ) (4,370 ) — (62,188 ) Proceeds from the sale of property, plant, and equipment — 2,791 6 — 2,797 Other — (178 ) — — (178 ) Net cash used for investing activities (492 ) (57,555 ) (4,364 ) — (62,411 ) Cash flow from financing activities: Proceeds from investment by member (2,075 ) 2,841 — — 766 Net proceeds from debt issuance 300,000 — — — 300,000 Loans received from and payments made on loans from other Summit Companies (26,242 ) 30,576 113 (4,447 ) — Payments on long-term debt (253,178 ) (3,076 ) (79 ) — (256,333 ) Payments on acquisition-related liabilities — (6,433 ) — — (6,433 ) Debt issuance costs (5,774 ) — — — (5,774 ) Distributions from partnership (2,500 ) — — — (2,500 ) Other (465 ) (36 ) — — (501 ) Net cash (used in) provided by financing activities 9,766 23,872 34 (4,447 ) 29,225 Impact of cash on foreign currency — — 191 — 191 Net decrease in cash (48,125 ) (7,113 ) (3,986 ) (4,447 ) (63,671 ) Cash — Beginning of period 117,219 8,440 7,719 (4,870 ) 128,508 Cash — End of period $ 69,094 $ 1,327 $ 3,733 $ (9,317 ) $ 64,837 Condensed Consolidating Statements of Cash Flows For the three months ended March 31, 2018 100% Owned Non- Issuers Guarantors Guarantors Eliminations Consolidated Net cash (used in) provided by operating activities $ (38,210 ) $ (15,050 ) $ 1,893 $ — $ (51,367 ) Cash flow from investing activities: Acquisitions, net of cash acquired — (113,993 ) — — (113,993 ) Purchase of property, plant and equipment (1,664 ) (46,363 ) (1,478 ) — (49,505 ) Proceeds from the sale of property, plant, and equipment — 7,668 120 — 7,788 Other — 1,500 — — 1,500 Net cash used for investing activities (1,664 ) (151,188 ) (1,358 ) — (154,210 ) Cash flow from financing activities: Proceeds from investment by member (73,661 ) 89,136 — — 15,475 Loans received from and payments made on loans from other Summit Companies (83,090 ) 82,599 (2,192 ) 2,683 — Payments on long-term debt (1,588 ) (2,380 ) (4 ) — (3,972 ) Payments on acquisition-related liabilities — (6,462 ) — — (6,462 ) Distributions from partnership (2,509 ) — — — (2,509 ) Other (827 ) (960 ) (33 ) — (1,820 ) Net cash provided by financing activities (161,675 ) 161,933 (2,229 ) 2,683 712 Impact of cash on foreign currency — — (398 ) — (398 ) Net increase in cash (201,549 ) (4,305 ) (2,092 ) 2,683 (205,263 ) Cash — Beginning of period 370,741 10,254 14,933 (12,372 ) 383,556 Cash — End of period $ 169,192 $ 5,949 $ 12,841 $ (9,689 ) $ 178,293

Summary of Organization and S_3

Summary of Organization and Significant Accounting Policies - General Information (Details)	3 Months Ended
	Mar. 30, 2019segmentplant
Summary Of Significant Accounting Policies And Recent Accounting Pronouncements [Line Items]
Number of operating segments	3
Number of reportable segments	3
Cement plant
Summary Of Significant Accounting Policies And Recent Accounting Pronouncements [Line Items]
Number of plants | plant	2
Summit Materials, LLC
Summary Of Significant Accounting Policies And Recent Accounting Pronouncements [Line Items]
Number of operating segments	3
Number of reportable segments	3
Summit Materials, LLC | Cement plant
Summary Of Significant Accounting Policies And Recent Accounting Pronouncements [Line Items]
Number of plants | plant	2
Summit Holdings LP
Summary Of Significant Accounting Policies And Recent Accounting Pronouncements [Line Items]
Voting power (as a percent)	100.00%

Summary of Organization and S_4

Summary of Organization and Significant Accounting Policies - Business and Credit Concentration (Details)	3 Months Ended
	Mar. 30, 2019state
Business and Credit Concentrations
Number of states in which the entity operates	23
Tax Receivable Agreement | Summit Holdings LP
Business and Credit Concentrations
Percentage of benefits to be paid on tax receivable agreement	85.00%
Percentage of the tax receivable agreement allocated to additional paid-in capital	15.00%

Summary of Organization and S_5

Summary of Organization and Significant Accounting Policies - New Accounting Standards (Details) - USD ($) $ in Thousands	Mar. 30, 2019	Dec. 30, 2018
Accounting Policies [Abstract]
Operating lease right-of-use assets	$ 34,403	$ 36,800
Operating lease liability	$ 35,298	$ 36,800

Goodwill and Intangibles - Summ

Goodwill and Intangibles - Summary of Goodwill by Reportable Segments (Details) $ in Thousands	3 Months Ended
	Mar. 30, 2019USD ($)
Goodwill [Roll Forward]
Balance, December 29, 2018	$ 1,192,028
Acquisitions	2,022
Foreign currency translation adjustments	1,212
Balance, March 30, 2019	1,195,262
West
Goodwill [Roll Forward]
Balance, December 29, 2018	580,567
Acquisitions	1,143
Foreign currency translation adjustments	1,212
Balance, March 30, 2019	582,922
East
Goodwill [Roll Forward]
Balance, December 29, 2018	406,805
Acquisitions	879
Foreign currency translation adjustments	0
Balance, March 30, 2019	407,684
Cement
Goodwill [Roll Forward]
Balance, December 29, 2018	204,656
Acquisitions	0
Foreign currency translation adjustments	0
Balance, March 30, 2019	204,656
Summit Materials, LLC
Goodwill [Roll Forward]
Balance, December 29, 2018	1,193,028
Acquisitions	2,022
Foreign currency translation adjustments	1,212
Balance, March 30, 2019	1,196,262
Summit Materials, LLC | West
Goodwill [Roll Forward]
Balance, December 29, 2018	581,567
Acquisitions	1,143
Foreign currency translation adjustments	1,212
Balance, March 30, 2019	583,922
Summit Materials, LLC | East
Goodwill [Roll Forward]
Balance, December 29, 2018	406,805
Acquisitions	879
Foreign currency translation adjustments	0
Balance, March 30, 2019	407,684
Summit Materials, LLC | Cement
Goodwill [Roll Forward]
Balance, December 29, 2018	204,656
Acquisitions	0
Foreign currency translation adjustments	0
Balance, March 30, 2019	$ 204,656

Goodwill and Intangibles - Inta

Goodwill and Intangibles - Intangible Assets By Type (Details) - USD ($) $ in Thousands	Mar. 30, 2019	Dec. 29, 2018
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 26,707	$ 26,707
Accumulated Amortization	(8,656)	(8,247)
Net Carrying Amount	18,051	18,460
Mineral leases
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	19,064	19,064
Accumulated Amortization	(5,548)	(5,259)
Net Carrying Amount	13,516	13,805
Reserve rights
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	6,234	6,234
Accumulated Amortization	(2,024)	(1,940)
Net Carrying Amount	4,210	4,294
Trade names
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	1,000	1,000
Accumulated Amortization	(883)	(858)
Net Carrying Amount	117	142
Other
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	409	409
Accumulated Amortization	(201)	(190)
Net Carrying Amount	208	219
Summit Materials, LLC
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	26,707	26,707
Accumulated Amortization	(8,656)	(8,247)
Net Carrying Amount	18,051	18,460
Summit Materials, LLC | Mineral leases
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	19,064	19,064
Accumulated Amortization	(5,548)	(5,259)
Net Carrying Amount	13,516	13,805
Summit Materials, LLC | Reserve rights
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	6,234	6,234
Accumulated Amortization	(2,024)	(1,940)
Net Carrying Amount	4,210	4,294
Summit Materials, LLC | Trade names
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	1,000	1,000
Accumulated Amortization	(883)	(858)
Net Carrying Amount	117	142
Summit Materials, LLC | Other
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	409	409
Accumulated Amortization	(201)	(190)
Net Carrying Amount	$ 208	$ 219

Goodwill and Intangibles - Amor

Goodwill and Intangibles - Amortization Expense (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 30, 2019	Mar. 31, 2018	Dec. 29, 2018
Business Acquisition [Line Items]
Amortization expense	$ 400	$ 300
Estimated amortization expense
2019 (nine months)	1,189
2020	1,510
2021	1,475
2022	1,482
2023	1,349
2024	1,254
Thereafter	9,792
Total	18,051		$ 18,460
Summit Materials, LLC
Business Acquisition [Line Items]
Amortization expense	400	$ 300
Estimated amortization expense
2019 (nine months)	1,189
2020	1,510
2021	1,475
2022	1,482
2023	1,349
2024	1,254
Thereafter	9,792
Total	$ 18,051		$ 18,460

Revenue Recognition - By Produc

Revenue Recognition - By Product (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 30, 2019	Mar. 31, 2018
Revenue from External Customer [Line Items]
Total revenue	$ 332,639	$ 314,421
Aggregates
Revenue from External Customer [Line Items]
Total revenue	87,872	67,450
Cement
Revenue from External Customer [Line Items]
Total revenue	32,499	33,117
Ready-mix concrete
Revenue from External Customer [Line Items]
Total revenue	117,320	122,015
Asphalt
Revenue from External Customer [Line Items]
Total revenue	23,038	18,141
Paving and related services
Revenue from External Customer [Line Items]
Total revenue	34,345	34,336
Other
Revenue from External Customer [Line Items]
Total revenue	37,565	39,362
Summit Materials, LLC
Revenue from External Customer [Line Items]
Total revenue	332,639	314,421
Summit Materials, LLC | Aggregates
Revenue from External Customer [Line Items]
Total revenue	87,872	67,450
Summit Materials, LLC | Cement
Revenue from External Customer [Line Items]
Total revenue	32,499	33,117
Summit Materials, LLC | Ready-mix concrete
Revenue from External Customer [Line Items]
Total revenue	117,320	122,015
Summit Materials, LLC | Asphalt
Revenue from External Customer [Line Items]
Total revenue	23,038	18,141
Summit Materials, LLC | Paving and related services
Revenue from External Customer [Line Items]
Total revenue	34,345	34,336
Summit Materials, LLC | Other
Revenue from External Customer [Line Items]
Total revenue	$ 37,565	$ 39,362

Revenue Recognition - Contract

Revenue Recognition - Contract Assets and Liabilities (Details) $ in Thousands	3 Months Ended
	Mar. 30, 2019USD ($)
Change in Contract with Customer, Asset [Abstract]
Beginning balance	$ 18,602
Changes in revenue billed, contract price or cost estimates	(1,541)
Other	18
Ending balance	17,079
Change in Contract with Customer, Liability [Abstract]
Beginning balance	11,840
Changes in revenue billed, contract price or cost estimates	(1,195)
Other	11
Ending balance	10,656
Summit Materials, LLC
Change in Contract with Customer, Asset [Abstract]
Beginning balance	18,602
Changes in revenue billed, contract price or cost estimates	(1,541)
Other	18
Ending balance	17,079
Change in Contract with Customer, Liability [Abstract]
Beginning balance	11,840
Changes in revenue billed, contract price or cost estimates	(1,195)
Other	11
Ending balance	$ 10,656

Revenue Recognition - Summary o

Revenue Recognition - Summary of Accounts Receivable, Net (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 30, 2019	Dec. 29, 2018
Accounts, Notes, Loans and Financing Receivable [Line Items]
Trade accounts receivable	$ 167,337	$ 157,601
Construction contract receivables	20,755	47,994
Retention receivables	12,902	15,010
Receivables from related parties	575	629
Accounts receivable	201,569	221,234
Less: Allowance for doubtful accounts	(6,158)	(6,716)
Accounts receivable, net	$ 195,411	214,518
Maximum
Accounts, Notes, Loans and Financing Receivable [Line Items]
General collection and billing period for retention receivables	1 year
Summit Materials, LLC
Accounts, Notes, Loans and Financing Receivable [Line Items]
Trade accounts receivable	$ 167,337	157,601
Construction contract receivables	20,755	47,994
Retention receivables	12,902	15,010
Receivables from related parties	575	629
Accounts receivable	201,569	221,234
Less: Allowance for doubtful accounts	(6,158)	(6,716)
Accounts receivable, net	$ 195,411	$ 214,518
Summit Materials, LLC | Maximum
Accounts, Notes, Loans and Financing Receivable [Line Items]
General collection and billing period for retention receivables	1 year

Inventories - Components of Inv

Inventories - Components of Inventories (Details) - USD ($) $ in Thousands	Mar. 30, 2019	Dec. 29, 2018
Inventory [Line Items]
Aggregate stockpiles	$ 146,132	$ 151,300
Finished goods	35,275	34,993
Work in process	7,947	7,478
Raw materials	24,684	20,080
Total	214,038	213,851
Summit Materials, LLC
Inventory [Line Items]
Aggregate stockpiles	146,132	151,300
Finished goods	35,275	34,993
Work in process	7,947	7,478
Raw materials	24,684	20,080
Total	$ 214,038	$ 213,851

Accrued Expenses - Components o

Accrued Expenses - Components of Accrued Expenses (Details) - USD ($) $ in Thousands	Mar. 30, 2019	Dec. 29, 2018
Schedule Of Accrued Expenses [Line Items]
Interest	$ 14,553	$ 26,223
Payroll and benefits	19,126	15,952
Finance lease obligations	17,407
Finance lease obligations		15,557
Insurance	16,071	13,625
Non-income taxes	9,876	7,442
Professional fees	625	1,408
Other	18,818	20,284
Total	96,476	100,491
Summit Materials, LLC
Schedule Of Accrued Expenses [Line Items]
Interest	14,553	26,223
Payroll and benefits	19,126	15,952
Finance lease obligations	17,407
Finance lease obligations		15,557
Insurance	16,071	13,625
Non-income taxes	10,107	7,674
Professional fees	625	1,408
Other	18,818	19,590
Total	$ 96,707	$ 100,029

Debt - Schedule of Debt (Detail

Debt - Schedule of Debt (Details) - USD ($) $ in Thousands	Mar. 30, 2019	Mar. 15, 2019	Dec. 29, 2018	Jun. 01, 2017	Jul. 08, 2015
Debt Instrument [Line Items]
Total debt	$ 1,875,099		$ 1,828,159
Total	4,765		6,354
Current portion of long-term debt	1,870,334		1,821,805
Gross amount	1,877,434
Debt discount	2,335
Term Loan, due 2024
Debt Instrument [Line Items]
Total debt	626,147		629,268
Gross amount	627,400		630,600
Debt discount	1,300		1,300
8 1/2% Senior Notes, due 2022
Debt Instrument [Line Items]
Total debt	$ 0		250,000
Debt instrument interest rate (as a percent)	8.50%
6 1/8% Senior Notes, due 2023
Debt Instrument [Line Items]
Total debt	$ 648,952		648,891
Gross amount	650,000		650,000
Debt discount	$ 1,000		1,100
Debt instrument interest rate (as a percent)	6.125%
5 1/8% Senior Notes, due 2025
Debt Instrument [Line Items]
Total debt	$ 300,000		300,000	$ 300,000
Debt instrument interest rate (as a percent)	5.125%
Summit Materials, LLC
Debt Instrument [Line Items]
Total	$ 1,875,099		1,828,159
Current portion of long-term debt	4,765		6,354
Gross amount	1,877,434
Debt discount	2,335
Summit Materials, LLC | Term Loan, due 2024
Debt Instrument [Line Items]
Total debt	626,147		629,268
Gross amount	627,400		630,600
Debt discount	1,300		1,300
Summit Materials, LLC | 8 1/2% Senior Notes, due 2022
Debt Instrument [Line Items]
Total debt	$ 0		250,000
Debt instrument interest rate (as a percent)	8.50%
Summit Materials, LLC | 6 1/8% Senior Notes, due 2023
Debt Instrument [Line Items]
Total debt	$ 648,952		648,891
Gross amount	650,000		650,000
Debt discount	$ 1,000		11,000
Debt instrument interest rate (as a percent)	6.125%				6.125%
Summit Materials, LLC | 5 1/8% Senior Notes, due 2025
Debt Instrument [Line Items]
Total debt	$ 300,000		300,000	$ 300,000
Debt instrument interest rate (as a percent)	5.125%			5.125%
Summit Materials, LLC | 6 1/2% Senior Notes, due 2027
Debt Instrument [Line Items]
Debt instrument interest rate (as a percent)	6.50%
Senior Notes | 6 1/2% Senior Notes, due 2027
Debt Instrument [Line Items]
Total debt	$ 300,000		0
Debt instrument interest rate (as a percent)	6.50%
Senior Notes | Summit Materials, LLC | 6 1/2% Senior Notes, due 2027
Debt Instrument [Line Items]
Total debt	$ 300,000	$ 300,000	$ 0
Debt instrument interest rate (as a percent)		6.50%

Debt - Schedule of Contractual

Debt - Schedule of Contractual Payments of Long-Term Debt (Details) $ in Thousands	Mar. 30, 2019USD ($)
Debt Instrument [Line Items]
2019 (nine months)	$ 3,177
2020	7,942
2021	6,354
2022	6,354
2023	656,354
2024	597,253
Thereafter	600,000
Total	1,877,434
Less: Original issue net discount	(2,335)
Less: Capitalized loan costs	(14,988)
Total debt	1,860,111
Summit Materials, LLC
Debt Instrument [Line Items]
2019 (nine months)	3,177
2020	7,942
2021	6,354
2022	6,354
2023	656,354
2024	597,253
Thereafter	600,000
Total	1,877,434
Less: Original issue net discount	(2,335)
Less: Capitalized loan costs	(14,988)
Total debt	$ 1,860,111

Debt - Senior Notes (Details)

Debt - Senior Notes (Details) - USD ($) $ in Thousands	Jun. 01, 2017	Jul. 08, 2015	Mar. 30, 2019	Mar. 15, 2019	Dec. 29, 2018
Debt Instrument [Line Items]
Long-term debt			$ 1,875,099		$ 1,828,159
Write off of deferred financing fees			2,851
5 1/8% Senior Notes, due 2025
Debt Instrument [Line Items]
Long-term debt	$ 300,000		$ 300,000		300,000
Senior notes, interest rate (as a percent)			5.125%
8 1/2% Senior Notes, due 2022
Debt Instrument [Line Items]
Long-term debt			$ 0		250,000
Senior notes, interest rate (as a percent)			8.50%
6 1/8% Senior Notes, due 2023
Debt Instrument [Line Items]
Long-term debt			$ 648,952		648,891
Senior notes, interest rate (as a percent)			6.125%
Issuers
Debt Instrument [Line Items]
Percentage of par value of senior notes	100.00%
Proceeds net of related fees and expenses	$ 295,400
Issuers | 5 1/8% Senior Notes, due 2025
Debt Instrument [Line Items]
Senior notes, interest rate (as a percent)	5.125%
Issuers | 8 1/2% Senior Notes, due 2022
Debt Instrument [Line Items]
Senior notes, interest rate (as a percent)			8.50%
Debt instrument, repurchased face amount			$ 250,000
Debt instrument redemption charge			14,565
Debt instrument, prepayment premium			11,700
Write off of deferred financing fees			2,900
Issuers | 6 1/8% Senior Notes, due 2023
Debt Instrument [Line Items]
Senior notes, interest rate (as a percent)		6.125%
Debt instrument, face amount		$ 650,000
Issuers | 6 1/8% Senior Notes, due 2023, issued at par
Debt Instrument [Line Items]
Debt instrument, face amount		$ 350,000
Issuers | 6 1/8% Senior Notes, due 2023, issued at 99.375% of par
Debt Instrument [Line Items]
Percentage of par value of senior notes		99.375%
Debt instrument, face amount		$ 300,000
Summit Materials, LLC
Debt Instrument [Line Items]
Write off of deferred financing fees			2,851
Summit Materials, LLC | 5 1/8% Senior Notes, due 2025
Debt Instrument [Line Items]
Long-term debt	$ 300,000		$ 300,000		300,000
Senior notes, interest rate (as a percent)	5.125%		5.125%
Summit Materials, LLC | 8 1/2% Senior Notes, due 2022
Debt Instrument [Line Items]
Long-term debt			$ 0		250,000
Senior notes, interest rate (as a percent)			8.50%
Debt instrument, repurchased face amount			$ 250,000
Debt instrument, prepayment premium			11,700
Write off of deferred financing fees			2,900
Summit Materials, LLC | 6 1/8% Senior Notes, due 2023
Debt Instrument [Line Items]
Long-term debt			$ 648,952		648,891
Senior notes, interest rate (as a percent)		6.125%	6.125%
Debt instrument, face amount		$ 650,000
Summit Materials, LLC | 6 1/2% Senior Notes, due 2027
Debt Instrument [Line Items]
Senior notes, interest rate (as a percent)			6.50%
Debt instrument redemption charge			$ 14,600
Senior Notes | 6 1/2% Senior Notes, due 2027
Debt Instrument [Line Items]
Long-term debt			$ 300,000		0
Senior notes, interest rate (as a percent)			6.50%
Senior Notes | Issuers | 6 1/2% Senior Notes, due 2027
Debt Instrument [Line Items]
Long-term debt				$ 300,000
Senior notes, interest rate (as a percent)				6.50%
Percentage of par value of senior notes	100.00%
Proceeds net of related fees and expenses	$ 296,300
Senior Notes | Summit Materials, LLC | 6 1/2% Senior Notes, due 2027
Debt Instrument [Line Items]
Long-term debt			$ 300,000	$ 300,000	$ 0
Senior notes, interest rate (as a percent)				6.50%
Percentage of par value of senior notes	100.00%
Proceeds net of related fees and expenses	$ 296,300

Debt - Senior Secured Credit Fa

Debt - Senior Secured Credit Facilities (Details) - USD ($)	May 22, 2018	Mar. 30, 2019	Feb. 28, 2019	Dec. 29, 2018	Jul. 08, 2015
Debt Instrument [Line Items]
Outstanding principal amount		$ 1,877,434,000
Summit Materials, LLC
Debt Instrument [Line Items]
Outstanding principal amount		1,877,434,000
6 1/8% Senior Notes, due 2023
Debt Instrument [Line Items]
Outstanding principal amount		650,000,000		$ 650,000,000
6 1/8% Senior Notes, due 2023 | Summit Materials, LLC
Debt Instrument [Line Items]
Debt instrument, face amount					$ 650,000,000
Outstanding principal amount		$ 650,000,000		650,000,000
Senior Secured Credit Facilities | Summit Materials, LLC
Debt Instrument [Line Items]
First lien leverage ratio		0.0475
Term Loan, due 2024
Debt Instrument [Line Items]
Outstanding principal amount		$ 627,400,000		630,600,000
Term Loan, due 2024 | Summit Materials, LLC
Debt Instrument [Line Items]
Debt instrument, face amount		$ 650,000,000
Quarterly principal repayments percentage		0.25%
Outstanding principal amount		$ 627,400,000		630,600,000
Revolving Credit Facility | Summit Materials, LLC
Debt Instrument [Line Items]
Maximum borrowing capacity		345,000,000	$ 345,000,000
Amount outstanding		0		$ 0
Remaining borrowing capacity		329,800,000
Revolving Credit Facility | Summit Materials, LLC | Federal funds rate
Debt Instrument [Line Items]
Basis spread on variable rate	0.50%
Revolving Credit Facility | Summit Materials, LLC | LIBOR Plus 1%
Debt Instrument [Line Items]
Basis spread on variable rate	2.00%
Percentage added to base rate	1.00%
Revolving Credit Facility | Summit Materials, LLC | LIBOR
Debt Instrument [Line Items]
Basis spread on variable rate	3.00%
Letter of Credit | Summit Materials, LLC
Debt Instrument [Line Items]
Amount outstanding		$ 15,200,000

Debt - Summary of Activity for

Debt - Summary of Activity for Deferred Financing Fees (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 30, 2019	Mar. 31, 2018
Deferred Finance Costs, Own-share Lending Arrangement, Issuance Costs, Accumulated Amortization [Roll Forward]
Beginning balance	$ 15,475	$ 19,033
Loan origination fees	5,774
Amortization	(998)	(1,013)
Write off of deferred financing fees	(2,851)
Ending balance	17,400	18,020
Summit Materials, LLC
Deferred Finance Costs, Own-share Lending Arrangement, Issuance Costs, Accumulated Amortization [Roll Forward]
Beginning balance	15,475	19,033
Loan origination fees	5,774
Amortization	(998)	(1,013)
Write off of deferred financing fees	(2,851)
Ending balance	$ 17,400	$ 18,020

Debt - Other (Details)

Debt - Other (Details) - CAD ($)	Jan. 15, 2015	Mar. 30, 2019	Dec. 29, 2018
Canadian subsidiary credit agreement, Operating activities
Debt Instrument [Line Items]
Revolving credit commitment	$ 6,000,000
Canadian subsidiary credit agreement, Capital equipment
Debt Instrument [Line Items]
Revolving credit commitment	$ 500,000
Basis spread on variable rate	0.90%
Canadian subsidiary credit agreement, Guarantees
Debt Instrument [Line Items]
Revolving credit commitment	$ 400,000
Canadian subsidiary credit agreement
Debt Instrument [Line Items]
Amount outstanding		$ 0	$ 0
Prime rate | Canadian subsidiary credit agreement, Operating activities
Debt Instrument [Line Items]
Basis spread on variable rate	0.20%
Summit Materials, LLC | Canadian subsidiary credit agreement, Operating activities
Debt Instrument [Line Items]
Revolving credit commitment	$ 6,000,000
Summit Materials, LLC | Canadian subsidiary credit agreement, Capital equipment
Debt Instrument [Line Items]
Revolving credit commitment	$ 500,000
Basis spread on variable rate	0.90%
Summit Materials, LLC | Canadian subsidiary credit agreement, Guarantees
Debt Instrument [Line Items]
Revolving credit commitment	$ 400,000
Summit Materials, LLC | Canadian subsidiary credit agreement
Debt Instrument [Line Items]
Amount outstanding		$ 0	$ 0
Summit Materials, LLC | Prime rate | Canadian subsidiary credit agreement, Operating activities
Debt Instrument [Line Items]
Basis spread on variable rate	0.20%

Income Taxes - Deferred Tax Ass

Income Taxes - Deferred Tax Assets and Tax Receivable Agreement (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 30, 2019	Mar. 31, 2018	Dec. 29, 2018
Income Taxes [Line Items]
Income tax expense (benefit)	$ (28,037)	$ (16,706)
Valuation Allowance
Valuation allowance	21,859		$ 19,366
Income tax provision, interest or penalties recognized	0	0
Deferred tax asset, Investment in limited partnership	100
Tax receivable agreement liability	309,733		309,674
Tax Receivable Agreement
Valuation Allowance
Tax receivable agreement liability			310,300
Tax Receivable Agreement | Accrued expenses.
Valuation Allowance
Tax receivable agreement liability			$ 600
Summit Holdings LP
Valuation Allowance
Distributions to LP Unitholders	$ 0	100
Summit Holdings LP | Tax Receivable Agreement
Valuation Allowance
Percentage of benefits to be paid on tax receivable agreement	85.00%
Summit Materials, LLC
Income Taxes [Line Items]
Income tax expense (benefit)	$ (7,806)	(3,844)
Valuation Allowance
Income tax provision, interest or penalties recognized	$ 0	$ 0
Common Class A
Valuation Allowance
Exchanges during period (in shares)	17,500	104,104

Earnings Per Share - Schedule o

Earnings Per Share - Schedule of Basic to Diluted Income Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 30, 2019	Mar. 31, 2018
Reconciliation of basic to diluted loss per share
Net loss attributable to Summit Inc.	$ (68,772)	$ (53,729)
Stock options
Reconciliation of basic to diluted loss per share
Anti dilutive shares excluded from calculation of earnings per share (in shares)	3,192,674	3,296,133
LP Units
Reconciliation of basic to diluted loss per share
Anti dilutive shares excluded from calculation of earnings per share (in shares)	3,418,018	3,585,516
Warrants
Reconciliation of basic to diluted loss per share
Anti dilutive shares excluded from calculation of earnings per share (in shares)	100,037	100,037
Time-vesting restricted stock units
Reconciliation of basic to diluted loss per share
Anti dilutive shares excluded from calculation of earnings per share (in shares)	1,589,396	854,482
Market-based restricted stock units
Reconciliation of basic to diluted loss per share
Anti dilutive shares excluded from calculation of earnings per share (in shares)	419,247	295,252
Common Class A
Reconciliation of basic to diluted loss per share
Weighted average shares of Class A stock outstanding (in shares)	111,811,679	110,659,098
Basic and diluted loss per share (usd per share)	$ (0.62)	$ (0.49)

Stockholders' Equity_Members'_3

Stockholders' Equity/Members' Interest - Equity Offerings (Details) - shares	3 Months Ended
	Mar. 30, 2019	Mar. 31, 2018	Dec. 29, 2018	Dec. 30, 2017
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Other (in shares)	391,104	1,033,875
Ownership percentage	97.00%	96.90%	97.00%	96.80%
Common Class A
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance (in shares)	111,658,927	110,350,594
Exchanges during period (in shares)	17,500	104,104
Other (in shares)	391,104	1,033,875
Ending balance (in shares)	112,067,531	111,488,573
Summit Materials, Inc. and Summit Holdings, LP
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance (in shares)	115,094,445	114,040,214
Exchanges during period (in shares)	0	0
Ending balance (in shares)	115,485,549	115,074,089
LP Units
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Number of LP Units exchanged (in shares)	(17,500)	(104,104)
LP Units | Summit Holdings LP
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Number of LP Units outstanding, beginning balance (in shares)	3,435,518	3,689,620
Number of LP Units outstanding, ending balance (in shares)	3,418,018	3,585,516
Summit Holdings LP
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Noncontrolling interest elimination (as a percent)	3.00%		3.00%

Stockholders' Equity_Members'_4

Stockholders' Equity/Members' Interest - Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 30, 2019	Mar. 31, 2018
Changes in each component of accumulated other comprehensive loss
Beginning balance	$ 1,327,741
Foreign currency translation adjustment, net of tax	1,704	$ (3,772)
Loss on cash flow hedges, net of tax	(120)	1,209
Ending balance	1,266,856
Summit Materials, LLC
Changes in each component of accumulated other comprehensive loss
Foreign currency translation adjustment, net of tax	2,358	706
Loss on cash flow hedges, net of tax	(166)	412
Change in retirement plans
Changes in each component of accumulated other comprehensive loss
Beginning balance	3,573	2,364
Ending balance	3,573	2,364
Change in retirement plans | Summit Materials, LLC
Changes in each component of accumulated other comprehensive loss
Beginning balance	(4,392)	(7,181)
Ending balance	(4,392)	(7,181)
Foreign currency translation adjustment
Changes in each component of accumulated other comprehensive loss
Beginning balance	(2,147)	4,637
Foreign currency translation adjustment, net of tax	1,704	(3,772)
Ending balance	(443)	865
Foreign currency translation adjustment | Summit Materials, LLC
Changes in each component of accumulated other comprehensive loss
Beginning balance	(19,370)	(17,790)
Foreign currency translation adjustment, net of tax	2,358	706
Ending balance	(17,012)	(17,084)
Cash flow hedge adjustments
Changes in each component of accumulated other comprehensive loss
Beginning balance	1,255	385
Loss on cash flow hedges, net of tax	(120)	1,209
Ending balance	1,135	1,594
Cash flow hedge adjustments | Summit Materials, LLC
Changes in each component of accumulated other comprehensive loss
Beginning balance	146	(2,473)
Loss on cash flow hedges, net of tax	(166)	412
Ending balance	(20)	(2,061)
Accumulated Other Comprehensive Income (Loss)
Changes in each component of accumulated other comprehensive loss
Beginning balance	2,681	7,386
Ending balance	4,265	4,823
Accumulated Other Comprehensive Income (Loss) | Summit Materials, LLC
Changes in each component of accumulated other comprehensive loss
Beginning balance	(23,616)	(27,444)
Ending balance	$ (21,424)	$ (26,326)

Supplemental Cash Flow Inform_3

Supplemental Cash Flow Information - Schedule of Supplemental Cash Flow Information (Details) - USD ($)	3 Months Ended
	Mar. 30, 2019	Mar. 31, 2018
Cash payments:
Interest	$ 21,126,000	$ 26,927,000
Income (refund) taxes	(20,000)
Income (refund) taxes		1,582,000
Operating cash payments on operating leases	2,837
Operating cash payments on finance leases	699
Non cash financing activities:	2,580
Right of use assets obtained in exchange for finance leases obligations
Right of use assets obtained in exchange for operating lease obligations	1,608,000
Right of use assets obtained in exchange for finance leases obligations	9,442,000
Exchange of LP Units to shares of Class A common stock	277,000	3,325,000
Summit Materials, LLC
Cash payments:
Interest	21,126,000	26,927,000
Income (refund) taxes	(20,000)
Income (refund) taxes		$ 1,582,000
Operating cash payments on operating leases	2,837,000
Operating cash payments on finance leases	699,000
Non cash financing activities:	2,580,000
Right of use assets obtained in exchange for finance leases obligations
Right of use assets obtained in exchange for operating lease obligations	1,608,000
Right of use assets obtained in exchange for finance leases obligations	$ 9,442,000

Leases - (Details)

Leases - (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 30, 2019	Dec. 30, 2018
Lease, Cost [Abstract]
Operating lease cost	$ 2,455
Variable lease cost	72
Short-term lease cost	6,581
Financing lease cost:
Amortization of right-of-use assets	2,623
Interest on lease liabilities	755
Total lease cost	12,486
Operating leases:
Operating lease right-of-use assets	34,403	$ 36,800
Current operating lease liabilities	8,098
Noncurrent operating lease liabilities	27,200
Total operating lease liabilities	35,298	36,800
Finance leases:
Property and equipment, gross	75,132
Less accumulated depreciation	(20,581)
Property and equipment, net	54,551
Current finance lease liabilities	17,407
Long-term finance lease liabilities	37,851
Total finance lease liabilities	$ 55,258
Lease Term
Operating leases	7 years 10 months 24 days
Finance lease	2 years 9 months 18 days
Discount Rate
Operating leases	5.60%
Finance lease	5.30%
Operating Leases
2019 (nine months)	$ 7,228
2020	8,737
2021	7,138
2022	4,370
2023	3,419
2024	2,235
Thereafter	11,212
Total lease payments	44,339
Less imputed interest	(9,041)
Finance Leases
2019 (nine months)	15,217
2020	15,703
2021	17,974
2022	6,556
2023	1,509
2024	1,750
Thereafter	2,667
Total lease payments	61,376
Less imputed interest	(6,118)
Summit Materials, LLC
Lease, Cost [Abstract]
Operating lease cost	2,455
Variable lease cost	72
Short-term lease cost	6,581
Financing lease cost:
Amortization of right-of-use assets	2,623
Interest on lease liabilities	755
Total lease cost	12,486
Operating leases:
Operating lease right-of-use assets	34,403	36,800
Current operating lease liabilities	8,098
Noncurrent operating lease liabilities	27,200
Total operating lease liabilities	35,298	$ 36,800
Finance leases:
Property and equipment, gross	75,132
Less accumulated depreciation	(20,581)
Property and equipment, net	54,551
Current finance lease liabilities	17,407
Long-term finance lease liabilities	37,851
Total finance lease liabilities	$ 55,258
Lease Term
Operating leases	7 years 10 months 24 days
Finance lease	2 years 9 months 18 days
Discount Rate
Operating leases	5.60%
Finance lease	5.30%
Operating Leases
2019 (nine months)	$ 7,228
2020	8,737
2021	7,138
2022	4,370
2023	3,419
2024	2,235
Thereafter	11,212
Total lease payments	44,339
Less imputed interest	(9,041)
Finance Leases
2019 (nine months)	15,217
2020	15,703
2021	17,974
2022	6,556
2023	1,509
2024	1,750
Thereafter	2,667
Total lease payments	61,376
Less imputed interest	$ (6,118)

Leases - Future Minimum Lease P

Leases - Future Minimum Lease Payments Under Topic 840 (Details) $ in Thousands	Dec. 29, 2018USD ($)
Lessee, Lease, Description [Line Items]
2019	$ 9,479
2020	8,101
2021	6,701
2022	4,279
2023	3,411
Summit Materials, LLC
Lessee, Lease, Description [Line Items]
2019	9,479
2020	8,101
2021	6,701
2022	4,279
2023	$ 3,411

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 30, 2019	Dec. 29, 2018
Loss Contingencies [Line Items]
Term of purchase commitments	1 year
Site Restoration Obligations
Loss Contingencies [Line Items]
Anticipated costs	$ 93.3	$ 92.5
Site Restoration Obligations | Other noncurrent liabilities
Loss Contingencies [Line Items]
Site restoration obligation, non-current	28.1	26.9
Site Restoration Obligations | Accrued expenses.
Loss Contingencies [Line Items]
Asset retirement obligation, current	$ 4	4.1
Summit Materials, LLC
Loss Contingencies [Line Items]
Term of purchase commitments	1 year
Summit Materials, LLC | Site Restoration Obligations
Loss Contingencies [Line Items]
Anticipated costs	$ 93.3	92.5
Summit Materials, LLC | Site Restoration Obligations | Other noncurrent liabilities
Loss Contingencies [Line Items]
Site restoration obligation, non-current	28.1	26.9
Summit Materials, LLC | Site Restoration Obligations | Accrued expenses.
Loss Contingencies [Line Items]
Asset retirement obligation, current	$ 4	$ 4.1

Fair Value - Fair Value Measure

Fair Value - Fair Value Measurements (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 30, 2019	Mar. 31, 2018	Dec. 29, 2018
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Current portion of acquisition-related liabilities and accrued expenses - contingent consideration	$ 4,568		$ 1,394
Acquisition-related liabilities and other noncurrent liabilities - contingent consideration	$ 1,205		5,175
Discount rate	10.00%
Adjustment to contingent consideration	$ 0	$ 0
Cash flow hedges | Interest rate derivatives | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Current portion of acquisition-related liabilities and accrued expenses - cash flow hedge	0		0
Acquisition-related liabilities and other noncurrent liabilities - cash flow hedge	0		0
Cash flow hedges | Interest rate derivatives | Term Loan, due 2022
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Term loan borrowings hedged by derivatives	200,000
Summit Materials, LLC | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Current portion of acquisition-related liabilities and accrued expenses - contingent consideration	4,568		1,394
Acquisition-related liabilities and other noncurrent liabilities - contingent consideration	$ 1,205		5,175
Discount rate	10.00%
Summit Materials, LLC | Cash flow hedges | Interest rate derivatives | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Current portion of acquisition-related liabilities and accrued expenses - cash flow hedge	$ 0		0
Acquisition-related liabilities and other noncurrent liabilities - cash flow hedge	0		$ 0
Summit Materials, LLC | Cash flow hedges | Interest rate derivatives | Term Loan, due 2022
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Term loan borrowings hedged by derivatives	$ 200,000

Fair Value - Carrying Value and

Fair Value - Carrying Value and Fair Value of Financial Instruments (Details) - USD ($) $ in Thousands	Mar. 30, 2019	Dec. 29, 2018
Financial Instruments
Current portion of debt	$ 4,765	$ 6,354
Summit Materials, LLC
Financial Instruments
Current portion of debt	1,875,099	1,828,159
Level 2
Financial Instruments
Current portion of debt	4,800	6,400
Level 2 | Fair Value
Financial Instruments
Long-term debt	1,865,816	1,777,722
Level 2 | Carrying Value
Financial Instruments
Long-term debt	1,875,099	1,828,159
Level 2 | Summit Materials, LLC
Financial Instruments
Current portion of debt	4,800	6,400
Level 2 | Summit Materials, LLC | Fair Value
Financial Instruments
Long-term debt	1,865,816	1,777,722
Level 2 | Summit Materials, LLC | Carrying Value
Financial Instruments
Long-term debt	1,875,099	1,828,159
Level 3 | Fair Value
Financial Instruments
Current portion of deferred consideration and noncompete obligations	32,854	32,876
Long term portion of deferred consideration and noncompete obligations	37,703	44,293
Level 3 | Carrying Value
Financial Instruments
Current portion of deferred consideration and noncompete obligations	32,854	32,876
Long term portion of deferred consideration and noncompete obligations	37,703	44,293
Level 3 | Summit Materials, LLC | Fair Value
Financial Instruments
Current portion of deferred consideration and noncompete obligations	30,354	30,376
Long term portion of deferred consideration and noncompete obligations	35,921	40,179
Level 3 | Summit Materials, LLC | Carrying Value
Financial Instruments
Current portion of deferred consideration and noncompete obligations	30,354	30,376
Long term portion of deferred consideration and noncompete obligations	$ 35,921	$ 40,179

Segment Information - Financial

Segment Information - Financial Data (Details) $ in Thousands	3 Months Ended
	Mar. 30, 2019USD ($)segment	Mar. 31, 2018USD ($)	Dec. 29, 2018USD ($)
Segment Reporting Information [Line Items]
Number of operating segments | segment	3
Number of reportable segments | segment	3
Total revenue	$ 332,639	$ 314,421
Loss from operations before taxes	(99,538)	(72,654)
Interest expense	30,105	28,784
Depreciation, depletion and amortization	54,807	46,543
Accretion	581	415
Loss on debt financings	14,565	0
Transaction costs	308	1,266
Non-cash compensation	5,906	8,507
Other	(146)	(7,348)
Total Adjusted EBITDA	6,588	5,513
Total purchases of property, plant and equipment	62,188	49,505
Total depreciation, depletion, amortization and accretion	55,388	46,958
Total assets	3,861,361		$ 3,857,641
West
Segment Reporting Information [Line Items]
Total revenue	181,945	181,713
East
Segment Reporting Information [Line Items]
Total revenue	113,388	95,157
Cement
Segment Reporting Information [Line Items]
Total revenue	37,306	37,551
Operating segment
Segment Reporting Information [Line Items]
Total purchases of property, plant and equipment	61,696	47,841
Total depreciation, depletion, amortization and accretion	54,436	46,248
Total assets	3,525,215		3,501,727
Operating segment | West
Segment Reporting Information [Line Items]
Total Adjusted EBITDA	14,298	16,173
Total purchases of property, plant and equipment	30,375	28,909
Total depreciation, depletion, amortization and accretion	23,925	22,151
Total assets	1,379,580		1,370,501
Operating segment | East
Segment Reporting Information [Line Items]
Total Adjusted EBITDA	3,242	(3,203)
Total purchases of property, plant and equipment	24,428	14,464
Total depreciation, depletion, amortization and accretion	20,211	17,727
Total assets	1,269,669		1,253,640
Operating segment | Cement
Segment Reporting Information [Line Items]
Total Adjusted EBITDA	(2,587)	3,667
Total purchases of property, plant and equipment	6,893	4,468
Total depreciation, depletion, amortization and accretion	10,300	6,370
Total assets	875,966		877,586
Corporate, Non-Segment
Segment Reporting Information [Line Items]
Total Adjusted EBITDA	(8,365)	(11,124)
Total purchases of property, plant and equipment	492	1,664
Total depreciation, depletion, amortization and accretion	952	710
Total assets	$ 336,146		355,914
Summit Materials, LLC
Segment Reporting Information [Line Items]
Number of operating segments | segment	3
Number of reportable segments | segment	3
Total revenue	$ 332,639	314,421
Loss from operations before taxes	(99,370)	(72,440)
Interest expense	29,937	28,570
Depreciation, depletion and amortization	54,807	46,543
Accretion	581	415
Loss on debt financings	14,565	0
Transaction costs	308	1,266
Non-cash compensation	5,906	8,507
Other	(146)	(7,348)
Total Adjusted EBITDA	6,588	5,513
Total purchases of property, plant and equipment	62,188	49,505
Total depreciation, depletion, amortization and accretion	55,388	46,958
Total assets	3,609,257		3,633,244
Summit Materials, LLC | West
Segment Reporting Information [Line Items]
Total revenue	181,945	181,713
Summit Materials, LLC | East
Segment Reporting Information [Line Items]
Total revenue	113,388	95,157
Summit Materials, LLC | Cement
Segment Reporting Information [Line Items]
Total revenue	37,306	37,551
Summit Materials, LLC | Operating segment
Segment Reporting Information [Line Items]
Total purchases of property, plant and equipment	61,696	47,841
Total depreciation, depletion, amortization and accretion	54,436	46,248
Total assets	3,525,215		3,501,727
Summit Materials, LLC | Operating segment | West
Segment Reporting Information [Line Items]
Total Adjusted EBITDA	14,298	16,173
Total purchases of property, plant and equipment	30,375	28,909
Total depreciation, depletion, amortization and accretion	23,925	22,151
Total assets	1,379,580		1,370,501
Summit Materials, LLC | Operating segment | East
Segment Reporting Information [Line Items]
Total Adjusted EBITDA	3,242	(3,203)
Total purchases of property, plant and equipment	24,428	14,464
Total depreciation, depletion, amortization and accretion	20,211	17,727
Total assets	1,269,669		1,253,640
Summit Materials, LLC | Operating segment | Cement
Segment Reporting Information [Line Items]
Total Adjusted EBITDA	(2,587)	3,667
Total purchases of property, plant and equipment	6,893	4,468
Total depreciation, depletion, amortization and accretion	10,300	6,370
Total assets	875,966		877,586
Summit Materials, LLC | Corporate, Non-Segment
Segment Reporting Information [Line Items]
Total Adjusted EBITDA	(8,365)	(11,124)
Total purchases of property, plant and equipment	492	1,664
Total depreciation, depletion, amortization and accretion	952	$ 710
Total assets	$ 84,042		$ 131,517

Guarantor and Non-Guarantor F_3

Guarantor and Non-Guarantor Financial Information - Schedule of Condensed Consolidating Balance Sheets (Details) - USD ($) $ in Thousands	Mar. 30, 2019	Dec. 30, 2018	Dec. 29, 2018	Mar. 31, 2018	Dec. 30, 2017
Current assets:
Cash and cash equivalents	$ 64,837		$ 128,508
Accounts receivable, net	195,411		214,518
Cost and estimated earnings in excess of billings	17,079		18,602
Inventories	214,038		213,851
Other current assets	19,245		16,061
Total current assets	510,610		591,540
Property, plant and equipment, net	1,799,941		1,780,132
Goodwill	1,195,262		1,192,028
Intangible assets	18,051		18,460
Operating lease right-of-use assets	34,403	$ 36,800
Other assets	49,990		50,084
Total assets	3,861,361		3,857,641
Current liabilities:
Current portion of debt	4,765		6,354
Current portion of acquisition-related liabilities	37,422		34,270
Accounts payable	101,843		107,702
Accrued expenses	96,476		100,491
Current operating lease liabilities	8,098
Billings in excess of costs and estimated earnings	10,656		11,840
Total current liabilities	259,260		260,657
Long-term debt	1,855,346		1,807,502
Acquisition-related liabilities	38,908		49,468
Noncurrent operating lease liabilities	27,200
Other noncurrent liabilities	92,439		88,195
Total liabilities	2,582,886		2,515,496
Total liabilities and stockholders’ equity	3,861,361		3,857,641
Summit Materials, LLC
Current assets:
Cash and cash equivalents	64,837		128,508	$ 178,293	$ 383,556
Accounts receivable, net	195,411		214,518
Intercompany receivables	0		0
Cost and estimated earnings in excess of billings	17,079		18,602
Inventories	214,038		213,851
Other current assets	19,245		16,061
Total current assets	510,610		591,540
Property, plant and equipment, net	1,799,941		1,780,132
Goodwill	1,196,262		1,193,028
Intangible assets	18,051		18,460
Operating lease right-of-use assets	34,403	$ 36,800
Other assets	49,990		50,084
Total assets	3,609,257		3,633,244
Current liabilities:
Current portion of debt	4,765		6,354
Current portion of acquisition-related liabilities	34,922		31,770
Accounts payable	102,454		109,008
Accrued expenses	96,707		100,029
Current operating lease liabilities	8,098
Intercompany payables	0		0
Billings in excess of costs and estimated earnings	10,656		11,840
Total current liabilities	257,602		259,001
Long-term debt	1,855,346		1,807,502
Acquisition-related liabilities	37,126		45,354
Noncurrent operating lease liabilities	27,200
Other noncurrent liabilities	132,253		135,956
Total liabilities	2,309,527		2,247,813
Total member's interest	1,299,730		1,385,431	1,240,542	1,291,594
Total liabilities and stockholders’ equity	3,609,257		3,633,244
Summit Materials, LLC | Eliminations
Current assets:
Cash and cash equivalents	(9,317)		(4,870)	(9,689)	(12,372)
Accounts receivable, net	(176)		(185)
Intercompany receivables	(1,081,992)		(1,125,192)
Cost and estimated earnings in excess of billings	0		0
Inventories	0		0
Other current assets	0		0
Total current assets	(1,091,485)		(1,130,247)
Property, plant and equipment, net	0		0
Goodwill	0		0
Intangible assets	0		0
Operating lease right-of-use assets	0
Other assets	(3,374,639)		(3,397,794)
Total assets	(4,466,124)		(4,528,041)
Current liabilities:
Current portion of debt	0		0
Current portion of acquisition-related liabilities	0		0
Accounts payable	(176)		(185)
Accrued expenses	(9,317)		(4,870)
Current operating lease liabilities	0
Intercompany payables	(1,081,992)		(1,125,192)
Billings in excess of costs and estimated earnings	0		0
Total current liabilities	(1,091,485)		(1,130,247)
Long-term debt	0		0
Acquisition-related liabilities	0		0
Noncurrent operating lease liabilities	0
Other noncurrent liabilities	(171,317)		(171,317)
Total liabilities	(1,262,802)		(1,301,564)
Total member's interest	(3,203,322)		(3,226,477)
Total liabilities and stockholders’ equity	(4,466,124)		(4,528,041)
Summit Materials, LLC | Issuers | Reportable Legal Entities
Current assets:
Cash and cash equivalents	69,094		117,219	169,192	370,741
Accounts receivable, net	9		0
Intercompany receivables	480,922		500,765
Cost and estimated earnings in excess of billings	0		0
Inventories	0		0
Other current assets	1,963		1,953
Total current assets	551,988		619,937
Property, plant and equipment, net	12,817		13,300
Goodwill	0		0
Intangible assets	0		0
Operating lease right-of-use assets	3,819
Other assets	3,270,321		3,292,851
Total assets	3,838,945		3,926,088
Current liabilities:
Current portion of debt	4,765		6,354
Current portion of acquisition-related liabilities	0		0
Accounts payable	2,435		4,712
Accrued expenses	37,556		45,146
Current operating lease liabilities	721
Intercompany payables	630,962		673,175
Billings in excess of costs and estimated earnings	0		0
Total current liabilities	676,439		729,387
Long-term debt	1,855,346		1,807,502
Acquisition-related liabilities	0		0
Noncurrent operating lease liabilities	4,058
Other noncurrent liabilities	3,372		3,768
Total liabilities	2,539,215		2,540,657
Total member's interest	1,299,730		1,385,431
Total liabilities and stockholders’ equity	3,838,945		3,926,088
Summit Materials, LLC | 100% Owned Guarantors | Reportable Legal Entities
Current assets:
Cash and cash equivalents	1,327		8,440	5,949	10,254
Accounts receivable, net	182,644		199,538
Intercompany receivables	601,070		624,427
Cost and estimated earnings in excess of billings	15,609		17,711
Inventories	210,662		210,149
Other current assets	13,908		11,308
Total current assets	1,025,220		1,071,573
Property, plant and equipment, net	1,727,295		1,709,083
Goodwill	1,138,807		1,136,785
Intangible assets	18,051		18,460
Operating lease right-of-use assets	25,004
Other assets	153,303		154,080
Total assets	4,087,680		4,089,981
Current liabilities:
Current portion of debt	0		0
Current portion of acquisition-related liabilities	34,922		31,770
Accounts payable	92,173		92,132
Accrued expenses	66,582		57,826
Current operating lease liabilities	6,365
Intercompany payables	434,273		436,564
Billings in excess of costs and estimated earnings	10,129		11,347
Total current liabilities	644,444		629,639
Long-term debt	0		0
Acquisition-related liabilities	37,126		45,354
Noncurrent operating lease liabilities	18,777
Other noncurrent liabilities	222,786		226,137
Total liabilities	923,133		901,130
Total member's interest	3,164,547		3,188,851
Total liabilities and stockholders’ equity	4,087,680		4,089,981
Summit Materials, LLC | Non-Guarantors | Reportable Legal Entities
Current assets:
Cash and cash equivalents	3,733		7,719	$ 12,841	$ 14,933
Accounts receivable, net	12,934		15,165
Intercompany receivables	0		0
Cost and estimated earnings in excess of billings	1,470		891
Inventories	3,376		3,702
Other current assets	3,374		2,800
Total current assets	24,887		30,277
Property, plant and equipment, net	59,829		57,749
Goodwill	57,455		56,243
Intangible assets	0		0
Operating lease right-of-use assets	5,580
Other assets	1,005		947
Total assets	148,756		145,216
Current liabilities:
Current portion of debt	0		0
Current portion of acquisition-related liabilities	0		0
Accounts payable	8,022		12,349
Accrued expenses	1,886		1,927
Current operating lease liabilities	1,012
Intercompany payables	16,757		15,453
Billings in excess of costs and estimated earnings	527		493
Total current liabilities	28,204		30,222
Long-term debt	0		0
Acquisition-related liabilities	0		0
Noncurrent operating lease liabilities	4,365
Other noncurrent liabilities	77,412		77,368
Total liabilities	109,981		107,590
Total member's interest	38,775		37,626
Total liabilities and stockholders’ equity	$ 148,756		$ 145,216

Guarantor and Non-Guarantor F_4

Guarantor and Non-Guarantor Financial Information - Schedule of Condensed Consolidating Statements of Operations and Comprehensive Loss (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 30, 2019	Mar. 31, 2018
Condensed Consolidating Statements of Operations
Revenue	$ 332,639	$ 314,421
Cost of revenue (excluding items shown separately below)	267,004	247,861
Depreciation, depletion, amortization and accretion	55,388	46,958
Operating loss	(57,671)	(51,525)
Loss from operations before taxes	(99,538)	(72,654)
Income tax expense (benefit)	(28,037)	(16,706)
Net loss attributable to Summit Inc.	(68,772)	(53,729)
Comprehensive income (loss) income attributable to member of Summit Materials, LLC	(67,188)	(56,292)
Summit Materials, LLC
Condensed Consolidating Statements of Operations
Revenue	332,639	314,421
Cost of revenue (excluding items shown separately below)	267,004	247,861
General and administrative expenses	67,918	71,127
Depreciation, depletion, amortization and accretion	55,388	46,958
Operating loss	(57,671)	(51,525)
Other (income) expense, net	11,762	(7,655)
Interest expense (income)	29,937	28,570
Gain on sale of business	0
Loss from operations before taxes	(99,370)	(72,440)
Income tax expense (benefit)	(7,806)	(3,844)
Net loss attributable to Summit Inc.	(91,564)	(68,596)
Comprehensive income (loss) income attributable to member of Summit Materials, LLC	(89,372)	(70,705)
Summit Materials, LLC | Eliminations
Condensed Consolidating Statements of Operations
Revenue	(1,183)	(1,418)
Cost of revenue (excluding items shown separately below)	(1,183)	(1,418)
General and administrative expenses	0	0
Depreciation, depletion, amortization and accretion	0	0
Operating loss	0	0
Other (income) expense, net	(29,504)	(18,213)
Interest expense (income)	0	0
Gain on sale of business	0
Loss from operations before taxes	29,504	18,213
Income tax expense (benefit)	0	0
Net loss attributable to Summit Inc.	29,504	18,213
Comprehensive income (loss) income attributable to member of Summit Materials, LLC	31,696	16,104
Issuers | Summit Materials, LLC | Reportable Legal Entities
Condensed Consolidating Statements of Operations
Revenue	0	0
Cost of revenue (excluding items shown separately below)	0	0
General and administrative expenses	14,930	20,947
Depreciation, depletion, amortization and accretion	952	710
Operating loss	(15,882)	(21,657)
Other (income) expense, net	43,611	17,365
Interest expense (income)	31,697	29,582
Gain on sale of business	0
Loss from operations before taxes	(91,190)	(68,604)
Income tax expense (benefit)	374	(8)
Net loss attributable to Summit Inc.	(91,564)	(68,596)
Comprehensive income (loss) income attributable to member of Summit Materials, LLC	(89,372)	(70,705)
100% Owned Guarantors | Summit Materials, LLC | Reportable Legal Entities
Condensed Consolidating Statements of Operations
Revenue	318,181	300,658
Cost of revenue (excluding items shown separately below)	256,166	238,127
General and administrative expenses	50,032	47,177
Depreciation, depletion, amortization and accretion	52,920	44,993
Operating loss	(40,937)	(29,639)
Other (income) expense, net	(1,942)	(6,858)
Interest expense (income)	(2,964)	(2,203)
Gain on sale of business	0
Loss from operations before taxes	(36,031)	(20,578)
Income tax expense (benefit)	(7,737)	(3,454)
Net loss attributable to Summit Inc.	(28,294)	(17,124)
Comprehensive income (loss) income attributable to member of Summit Materials, LLC	(28,128)	(18,119)
Non-Guarantors | Summit Materials, LLC | Reportable Legal Entities
Condensed Consolidating Statements of Operations
Revenue	15,641	15,181
Cost of revenue (excluding items shown separately below)	12,021	11,152
General and administrative expenses	2,956	3,003
Depreciation, depletion, amortization and accretion	1,516	1,255
Operating loss	(852)	(229)
Other (income) expense, net	(403)	51
Interest expense (income)	1,204	1,191
Gain on sale of business	0
Loss from operations before taxes	(1,653)	(1,471)
Income tax expense (benefit)	(443)	(382)
Net loss attributable to Summit Inc.	(1,210)	(1,089)
Comprehensive income (loss) income attributable to member of Summit Materials, LLC	$ (3,568)	$ 2,015

Guarantor and Non-Guarantor F_5

Guarantor and Non-Guarantor Financial Information - Schedule of Condensed Consolidating Statements of Cash Flows (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 30, 2019	Mar. 31, 2018
Condensed Consolidating Statements of Operations
Net cash (used in) provided by operating activities	$ (30,676)	$ (51,367)
Cash flow from investing activities:
Acquisitions, net of cash acquired	(2,842)	(113,993)
Purchase of property, plant and equipment	(62,188)	(49,505)
Proceeds from the sale of property, plant, and equipment	2,797	7,788
Other	(178)	1,500
Net cash used for investing activities	(62,411)	(154,210)
Cash flow from financing activities:
Net proceeds from debt issuance	300,000	0
Payments on long-term debt	(256,333)	(3,972)
Payments on acquisition-related liabilities	(8,933)	(8,962)
Financing costs	(5,774)	0
Distributions from partnership	0	(9)
Other	(501)	(1,820)
Net cash provided by financing activities	29,225	712
Cash and cash equivalents—beginning of period	128,508
Cash and cash equivalents—end of period	64,837
Summit Materials, LLC
Condensed Consolidating Statements of Operations
Net cash (used in) provided by operating activities	(30,676)	(51,367)
Cash flow from investing activities:
Acquisitions, net of cash acquired	(2,842)	(113,993)
Purchase of property, plant and equipment	(62,188)	(49,505)
Proceeds from the sale of property, plant, and equipment	2,797	7,788
Other	(178)	1,500
Net cash used for investing activities	(62,411)	(154,210)
Cash flow from financing activities:
Proceeds from investment by member	766	15,475
Net proceeds from debt issuance	300,000	0
Loans received from and payments made on loans from other Summit Companies	0	0
Payments on long-term debt	(256,333)	(3,972)
Payments on acquisition-related liabilities	(6,433)	(6,462)
Financing costs	(5,774)	0
Distributions from partnership	(2,500)	(2,509)
Other	(501)	(1,820)
Net cash provided by financing activities	29,225	712
Impact of foreign currency on cash	191	(398)
Net (decrease) increase in cash	(63,671)	(205,263)
Cash and cash equivalents—beginning of period	128,508	383,556
Cash and cash equivalents—end of period	64,837	178,293
Summit Materials, LLC | Eliminations
Condensed Consolidating Statements of Operations
Net cash (used in) provided by operating activities	0	0
Cash flow from investing activities:
Acquisitions, net of cash acquired	0	0
Purchase of property, plant and equipment	0	0
Proceeds from the sale of property, plant, and equipment	0	0
Other	0	0
Net cash used for investing activities	0	0
Cash flow from financing activities:
Proceeds from investment by member	0	0
Net proceeds from debt issuance	0
Loans received from and payments made on loans from other Summit Companies	(4,447)	2,683
Payments on long-term debt	0	0
Payments on acquisition-related liabilities	0	0
Financing costs	0
Distributions from partnership	0	0
Other	0	0
Net cash provided by financing activities	(4,447)	2,683
Impact of foreign currency on cash	0	0
Net (decrease) increase in cash	(4,447)	2,683
Cash and cash equivalents—beginning of period	(4,870)	(12,372)
Cash and cash equivalents—end of period	(9,317)	(9,689)
Summit Materials, LLC | Issuers | Reportable Legal Entities
Condensed Consolidating Statements of Operations
Net cash (used in) provided by operating activities	(57,399)	(38,210)
Cash flow from investing activities:
Acquisitions, net of cash acquired	0	0
Purchase of property, plant and equipment	(492)	(1,664)
Proceeds from the sale of property, plant, and equipment	0	0
Other	0	0
Net cash used for investing activities	(492)	(1,664)
Cash flow from financing activities:
Proceeds from investment by member	(2,075)	(73,661)
Net proceeds from debt issuance	300,000
Loans received from and payments made on loans from other Summit Companies	(26,242)	(83,090)
Payments on long-term debt	(253,178)	(1,588)
Payments on acquisition-related liabilities	0	0
Financing costs	(5,774)
Distributions from partnership	(2,500)	(2,509)
Other	(465)	(827)
Net cash provided by financing activities	9,766	(161,675)
Impact of foreign currency on cash	0	0
Net (decrease) increase in cash	(48,125)	(201,549)
Cash and cash equivalents—beginning of period	117,219	370,741
Cash and cash equivalents—end of period	69,094	169,192
Summit Materials, LLC | 100% Owned Guarantors | Reportable Legal Entities
Condensed Consolidating Statements of Operations
Net cash (used in) provided by operating activities	26,570	(15,050)
Cash flow from investing activities:
Acquisitions, net of cash acquired	(2,842)	(113,993)
Purchase of property, plant and equipment	(57,326)	(46,363)
Proceeds from the sale of property, plant, and equipment	2,791	7,668
Other	(178)	1,500
Net cash used for investing activities	(57,555)	(151,188)
Cash flow from financing activities:
Proceeds from investment by member	2,841	89,136
Net proceeds from debt issuance	0
Loans received from and payments made on loans from other Summit Companies	30,576	82,599
Payments on long-term debt	(3,076)	(2,380)
Payments on acquisition-related liabilities	(6,433)	(6,462)
Financing costs	0
Distributions from partnership	0	0
Other	(36)	(960)
Net cash provided by financing activities	23,872	161,933
Impact of foreign currency on cash	0	0
Net (decrease) increase in cash	(7,113)	(4,305)
Cash and cash equivalents—beginning of period	8,440	10,254
Cash and cash equivalents—end of period	1,327	5,949
Summit Materials, LLC | Non-Guarantors | Reportable Legal Entities
Condensed Consolidating Statements of Operations
Net cash (used in) provided by operating activities	153	1,893
Cash flow from investing activities:
Acquisitions, net of cash acquired	0	0
Purchase of property, plant and equipment	(4,370)	(1,478)
Proceeds from the sale of property, plant, and equipment	6	120
Other	0	0
Net cash used for investing activities	(4,364)	(1,358)
Cash flow from financing activities:
Proceeds from investment by member	0	0
Net proceeds from debt issuance	0
Loans received from and payments made on loans from other Summit Companies	113	(2,192)
Payments on long-term debt	(79)	(4)
Payments on acquisition-related liabilities	0	0
Financing costs	0
Distributions from partnership	0	0
Other	0	(33)
Net cash provided by financing activities	34	(2,229)
Impact of foreign currency on cash	191	(398)
Net (decrease) increase in cash	(3,986)	(2,092)
Cash and cash equivalents—beginning of period	7,719	14,933
Cash and cash equivalents—end of period	$ 3,733	$ 12,841