Summit Materials (SUM) 10-Q 6 Nov 18 2018 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 29, 2018	Nov. 01, 2018
Document Information [Line Items]
Entity Registrant Name	Summit Materials, Inc.
Entity Central Index Key	1,621,563
Document Type	10-Q
Document Period End Date	Sep. 29, 2018
Amendment Flag	false
Current Fiscal Year End Date	--12-29
Entity Filer Category	Large Accelerated Filer
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	Q3
Common Class A
Document Information [Line Items]
Entity common stock, shares outstanding (in shares)		111,656,101
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	1,571,371
Document Type	10-Q
Document Period End Date	Sep. 29, 2018
Amendment Flag	false
Current Fiscal Year End Date	--12-29
Entity Filer Category	Non-accelerated Filer
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	Q3

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 29, 2018	Dec. 30, 2017
Current assets:
Cash and cash equivalents	$ 64,930	$ 383,556
Accounts receivable, net	301,670	198,330
Costs and estimated earnings in excess of billings	47,629	9,512
Inventories	229,761	184,439
Other current assets	15,690	7,764
Total current assets	659,680	783,601
Property, plant and equipment, less accumulated depreciation, depletion and amortization (September 29, 2018 - $748,265 and December 30, 2017 - $631,841)	1,751,810	1,615,424
Goodwill	1,147,588	1,036,320
Intangible assets, less accumulated amortization (September 29, 2018 - $7,819 and December 30, 2017 - $6,698)	18,892	16,833
Deferred tax assets, less valuation allowance (September 29, 2018 and December 30, 2017 - $1,675)	267,532	284,092
Other assets	50,832	51,063
Total assets	3,896,334	3,787,333
Current liabilities:
Current portion of debt	4,765	4,765
Current portion of acquisition-related liabilities	14,148	14,087
Accounts payable	140,174	98,744
Accrued expenses	114,257	116,629
Billings in excess of costs and estimated earnings	13,072	15,750
Total current liabilities	286,416	249,975
Long-term debt	1,808,190	1,810,833
Acquisition-related liabilities	29,129	58,135
Tax receivable agreement liability	333,152	331,340
Other noncurrent liabilities	80,577	65,329
Total liabilities	2,537,464	2,515,612
Commitments and contingencies (see note 11)
Stockholders’ equity:
Additional paid-in capital	1,188,707	1,154,220
Accumulated earnings	148,902	95,833
Accumulated other comprehensive income	6,134	7,386
Stockholders’ equity	1,344,860	1,258,543
Noncontrolling interest in Summit Holdings	14,010	13,178
Total stockholders’ equity	1,358,870	1,271,721
Total liabilities and stockholders’ equity	3,896,334	3,787,333
Summit Materials, LLC
Current assets:
Cash and cash equivalents	64,930	383,556
Accounts receivable, net	301,670	198,330
Costs and estimated earnings in excess of billings	47,629	9,512
Inventories	229,761	184,439
Other current assets	15,690	7,764
Total current assets	659,680	783,601
Property, plant and equipment, less accumulated depreciation, depletion and amortization (September 29, 2018 - $748,265 and December 30, 2017 - $631,841)	1,751,810	1,615,424
Goodwill	1,148,588	1,037,320
Intangible assets, less accumulated amortization (September 29, 2018 - $7,819 and December 30, 2017 - $6,698)	18,892	16,833
Other assets	50,832	51,063
Total assets	3,629,802	3,504,241
Current liabilities:
Current portion of debt	4,765	4,765
Current portion of acquisition-related liabilities	11,648	11,587
Accounts payable	141,480	100,637
Accrued expenses	114,488	116,274
Billings in excess of costs and estimated earnings	13,072	15,750
Total current liabilities	285,453	249,013
Long-term debt	1,808,190	1,810,833
Acquisition-related liabilities	25,185	52,239
Other noncurrent liabilities	121,717	100,562
Total liabilities	2,240,545	2,212,647
Commitments and contingencies (see note 11)
Stockholders’ equity:
Members' equity	1,390,726	1,359,760
Accumulated earnings	17,402	(51,031)
Accumulated other comprehensive income	(18,871)	(17,135)
Total member's interest	1,389,257	1,291,594
Total liabilities and stockholders’ equity	3,629,802	3,504,241
Common Class A
Stockholders’ equity:
Common stock	1,117	1,104
Class B Common Stock
Stockholders’ equity:
Common stock	$ 0	$ 0

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Sep. 29, 2018	Dec. 30, 2017
Property, plant and equipment, accumulated depreciation, depletion and amortization	$ 748,265	$ 631,841
Intangible assets, accumulated amortization	7,819	6,698
Deferred tax assets, valuation allowance	1,675	1,675
Summit Materials, LLC
Property, plant and equipment, accumulated depreciation, depletion and amortization	748,265	631,841
Intangible assets, accumulated amortization	$ 7,819	$ 6,698
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)	111,654,552	110,350,594
Common stock, shares outstanding (in shares)	111,654,552	110,350,594
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	100
Common stock, shares outstanding (in shares)	99	100

Unaudited Consolidated Statemen

Unaudited Consolidated Statements of Operations - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 29, 2018	Sep. 30, 2017	Sep. 29, 2018	Sep. 30, 2017
Revenue:
Product	$ 512,822	$ 465,556	$ 1,229,596	$ 1,088,299
Service	112,195	108,831	234,572	223,500
Net revenue	625,017	574,387	1,464,168	1,311,799
Delivery and subcontract revenue	69,644	59,794	145,804	130,752
Total revenue	694,661	634,181	1,609,972	1,442,551
Cost of revenue (excluding items shown separately below):
Product	321,586	277,301	814,166	677,861
Service	80,573	72,450	170,626	154,408
Net cost of revenue	402,159	349,751	984,792	832,269
Delivery and subcontract cost	69,644	59,794	145,804	130,752
Total cost of revenue	471,803	409,545	1,130,596	963,021
General and administrative expenses	59,457	59,175	190,975	175,729
Depreciation, depletion, amortization and accretion	53,974	48,969	150,663	133,756
Transaction costs	1,260	2,581	3,817	6,474
Operating income	108,167	113,911	133,921	163,571
Interest expense	28,889	28,921	86,616	79,876
Loss on debt financings	0	0	149	190
Tax receivable agreement expense	0	501,752	0	503,277
Gain on sale of business	(12,108)	0	(12,108)	0
Other income, net	(3,371)	(2,716)	(11,942)	(3,963)
Income (loss) from operations before taxes	94,757	(414,046)	71,206	(415,809)
Income tax expense (benefit)	20,765	(498,333)	16,249	(497,076)
Net income	73,992	84,287	54,957	81,267
Net income (loss) attributable to noncontrolling interest in subsidiaries	0	59	0	(27)
Net income attributable to Summit Holdings	2,703	2,964	1,888	2,474
Net income attributable to Summit Inc.	71,289	81,264	53,069	78,820
Summit Materials, LLC
Revenue:
Product	512,822	465,556	1,229,596	1,088,299
Service	112,195	108,831	234,572	223,500
Net revenue	625,017	574,387	1,464,168	1,311,799
Delivery and subcontract revenue	69,644	59,794	145,804	130,752
Total revenue	694,661	634,181	1,609,972	1,442,551
Cost of revenue (excluding items shown separately below):
Product	321,586	277,301	814,166	677,861
Service	80,573	72,450	170,626	154,408
Net cost of revenue	402,159	349,751	984,792	832,269
Delivery and subcontract cost	69,644	59,794	145,804	130,752
Total cost of revenue	471,803	409,545	1,130,596	963,021
General and administrative expenses	59,457	59,175	190,975	175,729
Depreciation, depletion, amortization and accretion	53,974	48,969	150,663	133,756
Transaction costs	1,260	2,581	3,817	6,474
Operating income	108,167	113,911	133,921	163,571
Interest expense	28,720	28,708	86,066	79,195
Loss on debt financings	0	0	149	190
Gain on sale of business	(12,108)	0	(12,108)	0
Other income, net	(3,371)	(2,716)	(11,942)	(3,963)
Income (loss) from operations before taxes	94,926	87,919	71,756	88,149
Income tax expense (benefit)	4,499	5,286	3,323	6,543
Net income	90,427	82,633	68,433	81,606
Net income (loss) attributable to noncontrolling interest	0	59	0	(27)
Net income attributable to Summit Inc.	$ 90,427	$ 82,574	$ 68,433	$ 81,633
Common Class A
Income per share of Class A common stock:
Basic (usd per share)	$ 0.64	$ 0.74	$ 0.48	$ 0.73
Diluted (usd per share)	$ 0.64	$ 0.73	$ 0.47	$ 0.72
Weighted average shares of Class A common stock:
Basic (in shares)	111,641,344	109,545,111	111,288,211	108,219,132
Diluted (in shares)	111,940,067	110,824,468	112,472,724	108,848,680

Unaudited Consolidated Statem_2

Unaudited Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 29, 2018	Sep. 30, 2017	Sep. 29, 2018	Sep. 30, 2017
Comprehensive income (loss)
Net income	$ 73,992	$ 84,287	$ 54,957	$ 81,267
Other comprehensive income (loss):
Postretirement liability adjustment	0	0	0	413
Foreign currency translation adjustment	1,970	4,374	(3,179)	8,498
Income on cash flow hedges	87	212	1,443	384
Less tax effect of other comprehensive income (loss) items	(507)	0	428	0
Other comprehensive income (loss):	1,550	4,586	(1,308)	9,295
Comprehensive income	75,542	88,873	53,649	90,562
Less comprehensive income (loss) attributable to the noncontrolling interest in consolidated subsidiaries	0	59	0	(27)
Less comprehensive income attributable to Summit Holdings	5,505	3,135	1,832	2,832
Comprehensive income attributable to Summit Inc.	70,037	85,679	51,817	87,757
Summit Materials, LLC
Comprehensive income (loss)
Net income	90,427	82,633	68,433	81,606
Other comprehensive income (loss):
Postretirement liability adjustment	0	0	0	413
Foreign currency translation adjustment	1,970	4,374	(3,179)	8,498
Income on cash flow hedges	87	212	1,443	384
Other comprehensive income (loss):	2,057	4,586	(1,736)	9,295
Comprehensive income	92,484	87,219	66,697	90,901
Less comprehensive income (loss) attributable to noncontrolling interest	0	59	0	(27)
Comprehensive income attributable to Summit Inc.	$ 92,484	$ 87,160	$ 66,697	$ 90,928

Unaudited Consolidated Statem_3

Unaudited Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 29, 2018	Sep. 30, 2017
Cash flow from operating activities:
Net income	$ 54,957	$ 81,267
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, depletion, amortization and accretion	152,829	140,634
Share-based compensation expense	19,833	14,148
Net gain on asset disposals	(27,261)	(6,063)
Non-cash loss on debt financings	0	85
Change in deferred tax asset, net	12,577	(498,816)
Other	873	(855)
(Increase) decrease in operating assets, net of acquisitions and dispositions:
Accounts receivable, net	(90,481)	(98,961)
Inventories	(26,027)	(12,835)
Costs and estimated earnings in excess of billings	(37,643)	(31,606)
Other current assets	(6,819)	6,026
Other assets	(1,217)	(3,141)
Increase (decrease) in operating liabilities, net of acquisitions and dispositions:
Accounts payable	24,978	38,357
Accrued expenses	(2,197)	3,854
Billings in excess of costs and estimated earnings	(3,850)	2,386
Tax receivable agreement liability	1,812	503,277
Other liabilities	(1,807)	(5,324)
Net cash provided by operating activities	70,557	132,433
Cash flow from investing activities:
Acquisitions, net of cash acquired	(210,894)	(371,479)
Purchases of property, plant and equipment	(183,752)	(147,478)
Proceeds from the sale of property, plant and equipment	18,426	13,290
Proceeds from sale of business	21,564	0
Other	2,660	182
Net cash used for investing activities	(351,996)	(505,485)
Cash flow from financing activities:
Proceeds from equity offerings	0	237,600
Capital issuance costs	0	(627)
Proceeds from debt issuances	64,500	302,000
Debt issuance costs	(550)	(5,317)
Payments on debt	(79,027)	(12,887)
Payments on acquisition-related liabilities	(35,321)	(22,616)
Distributions from partnership	(69)	(109)
Proceeds from stock option exercises	15,615	18,810
Other	(1,913)	(846)
Net cash (used in) provided by financing activities	(36,765)	516,008
Impact of foreign currency on cash	(422)	734
Net (decrease) increase in cash	(318,626)	143,690
Cash and cash equivalents—beginning of period	383,556	143,392
Cash and cash equivalents—end of period	64,930	287,082
Summit Materials, LLC
Cash flow from operating activities:
Net income	68,433	81,606
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, depletion, amortization and accretion	152,279	139,953
Share-based compensation expense	19,833	14,148
Net gain on asset disposals	(27,261)	(6,063)
Non-cash loss on debt financings	0	85
Change in deferred tax asset, net	1,463	4,768
Other	873	(855)
(Increase) decrease in operating assets, net of acquisitions and dispositions:
Accounts receivable, net	(90,481)	(98,961)
Inventories	(26,027)	(12,835)
Costs and estimated earnings in excess of billings	(37,643)	(31,606)
Other current assets	(6,819)	6,043
Other assets	(1,217)	(3,141)
Increase (decrease) in operating liabilities, net of acquisitions and dispositions:
Accounts payable	24,392	37,705
Accrued expenses	(1,611)	4,986
Billings in excess of costs and estimated earnings	(3,850)	2,386
Other liabilities	(1,807)	(5,324)
Net cash provided by operating activities	70,557	132,895
Cash flow from investing activities:
Acquisitions, net of cash acquired	(210,894)	(371,479)
Purchases of property, plant and equipment	(183,752)	(147,478)
Proceeds from the sale of property, plant and equipment	18,426	13,290
Proceeds from sale of business	21,564	0
Other	2,660	182
Net cash used for investing activities	(351,996)	(505,485)
Cash flow from financing activities:
Capital contributions by member	15,615	256,667
Capital issuance costs	0	(627)
Proceeds from debt issuances	64,500	302,000
Debt issuance costs	(550)	(5,317)
Payments on debt	(79,027)	(12,887)
Payments on acquisition-related liabilities	(32,821)	(20,116)
Distributions from partnership	(2,569)	(2,609)
Other	(1,913)	(845)
Net cash (used in) provided by financing activities	(36,765)	516,266
Impact of foreign currency on cash	(422)	734
Net (decrease) increase in cash	(318,626)	144,410
Cash and cash equivalents—beginning of period	383,556	142,672
Cash and cash equivalents—end of period	$ 64,930	$ 287,082

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 (in shares) at Dec. 31, 2016			97,554,278
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	$ 81,267	$ 81,606										$ 1,154,220
LP Unit exchanges (in shares)			1,255,266
Other comprehensive loss, net of tax	9,295	9,295
Other (in shares)			1,177,200
Ending balance (in shares) at Sep. 30, 2017			109,986,744
Beginning balance at Dec. 30, 2017	1,271,721					$ 95,833		$ 7,386		$ 1,104			$ 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	100						110,350,594	100
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net contributed capital		15,615			15,615
Net income	54,957	68,433				53,069	68,433				$ 0		1,888
LP Unit exchanges (in shares)										254,102
LP Unit exchanges	0									$ 2		929	(931)
Other comprehensive loss, net of tax	(1,308)	(1,736)						(1,252)	(1,736)				(56)
Stock option exercises (in shares)										863,898
Stock option exercises	15,616									$ 9		15,607
Share-based compensation	19,833	19,833			19,833							19,833
Distributions from partnership	(69)												(69)
Distributions		(2,569)			(2,569)
Other (in shares)			1,049,856							185,958	(1)
Other	(1,880)	(1,913)			(1,913)					$ 2		(1,882)
Ending balance at Sep. 29, 2018	$ 1,358,870					$ 148,902		$ 6,134		$ 1,117	$ 0	$ 1,188,707	$ 14,010
Ending balance at Sep. 29, 2018		$ 1,389,257			$ 1,390,726		$ 17,402		$ (18,871)
Ending balance (in shares) at Sep. 29, 2018			111,654,552	99						111,654,552	99

Summary of Organization and Sig

Summary of Organization and Significant Accounting Policies	9 Months Ended
	Sep. 29, 2018
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 30, 2017 . 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 September 29, 2018 , the results of operations for the three and nine months ended September 29, 2018 and September 30, 2017 and cash flows for the nine months ended September 29, 2018 and September 30, 2017 . 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. The Company attributes consolidated stockholders’ equity and net income separately to the controlling and noncontrolling interests. The Company accounts for investments in entities for which it has an ownership of 20% to 50% using the equity method of accounting. In October 2017, the Company acquired the 20% of Ohio Valley Asphalt, LLC held by noncontrolling interests, making it a wholly owned subsidiary. 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 those states, as well as specific situations affecting individual customers. Credit granted within the Company’s trade areas has been extended 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 and nine months ended September 29, 2018 and September 30, 2017 . 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. Aggregates and cement products are sold point-of-sale through purchase orders. When the product is sold on account, collectability typically occurs 30 to 60 days after the sale. Revenue is recognized when cash is received from the customer at the point of sale or when the products are delivered or collected on site. There are no other timing implications that will create a contract asset or liability, and contract modifications are unlikely given the timing and nature of the transaction. Material sales are likely to have multiple performance obligations if the product is sold with delivery. In these instances, delivery most often occurs on the same day as the control of the product transfers to the customer. As a result, even in the case of multiple performance obligations, the performance obligations are satisfied concurrently and revenue is recognized simultaneously. 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. Collectability of service contracts is due reasonably after certain milestones in the contract are performed. Milestones vary by project, but are typically calculated using monthly progress based on the percentage of completion or a customer’s engineer review of progress. The majority of the time, collection occurs within 90 days of billing and cash is received within the same fiscal year as services performed. On most projects, the customer will withhold a portion of the invoice for retainage, which may last longer than a year depending on the job. 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 and nine months ended September 29, 2018 . We recognize claims when the amount of the claim can be estimated reliably and its realization is probable. In evaluating these criteria, we consider the contractual basis for the claim, the cause of any additional costs incurred, the reasonableness of those costs and the objective evidence available to support the claim. When the contract includes variable consideration, we estimate the amount of consideration to which we will be entitled in exchange for transferring the promised goods or services to a customer. The amount of estimated variable consideration included in the transaction price is the amount for which it is probable that a significant reversal in the amount of cumulative revenue recognized will not occur when the uncertainty associated with the variable consideration is subsequently resolved. Types of variable consideration include, but are not limited to, liquidated damages and other performance penalties and production and placement bonuses. The majority of contract modifications relate to the original contract and are often an extension of the original performance obligation. Predominately modifications are not distinct from the terms in the original contract; therefore, they are considered part of a single performance obligation. We account for the modification using a cumulative catch-up adjustment. However, there are instances where goods or services in a modification are distinct from those transferred prior to the modification. In these situations, we account for the modifications as either a separate contract or prospectively depending on the facts and circumstances of the modification. Generally, construction contracts contain mobilization costs which are categorized as costs to fulfill a contract. These costs are excluded from any measure of progress toward contract fulfillment. These costs do not result in the transfer of control of a good or service to the customer and are amortized over the life of the contract. 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 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 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. Reclassification — Within the operating activities section on the consolidated statement of cash flows for the nine month period ended September 30, 2017 , the Company reclassified $4.8 million from deferred income tax benefit, $ 17,000 from other current assets and $498.8 million from deferred tax assets, net, to change in deferred tax asset, net, to conform to the current year presentation. New Accounting Standards — In May 2014, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2014-09, Revenue from Contracts with Customers , which prescribes a five-step model for revenue recognition that replaced most existing revenue recognition guidance in U.S. GAAP. The ASU supersedes nearly all existing revenue recognition guidance under U.S. GAAP and provides that an entity recognize revenue when it transfers promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. This update also requires additional disclosure about the nature, amount, timing and uncertainty of revenue and cash flows arising from customer contracts, including significant judgments and changes in judgments, and assets recognized from costs incurred to obtain or fulfill a contract. In July 2015, the FASB postponed the effective date of the new revenue standard by one year to the first quarter of 2018. We adopted this ASU in the first quarter of 2018 using the modified retrospective approach, which did not have a material impact on our consolidated financial statements. In January 2017, the FASB issued ASU No. 2017-01, Clarifying the Definition of a Business, which narrows the definition of a business. This ASU provides a screen to determine whether a group of assets constitutes a business. The screen requires that when substantially all of the fair value of the gross assets acquired (or disposed of) is concentrated in a single identifiable asset or a group of similar identifiable assets, the set is not a business. This screen reduces the number of transactions that need to be further evaluated as acquisitions. If the screen is not met, this ASU (1) requires that to be considered a business, a set must include, at a minimum, an input and a substantive process that together significantly contribute to the ability to create an output and (2) removes the evaluation of whether a market participant could replace missing elements. Although outputs are not required for a set to be a business, outputs generally are a key element of a business; therefore, the FASB has developed more stringent criteria for sets without outputs. We adopted this ASU in the first quarter of 2018 and the adoption of this ASU did not have a material impact on the consolidated financial statements.
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. Summit Inc. Equity Offering —On January 10, 2017, Summit Inc. raised $237.6 million , net of underwriting discounts, through the issuance of 10,000,000 shares of Class A common stock at a public offering price of $24.05 per share. Summit Inc. used these proceeds to purchase an equal number of limited partnership interests in Summit Holdings (“LP Units”) and caused Summit Holdings to use a portion of the proceeds from the offering to acquire two materials-based companies for a combined purchase price of approximately $110 million in cash. 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 30, 2017. 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 September 29, 2018 , the results of operations for the three and nine months ended September 29, 2018 and September 30, 2017 and cash flows for the nine months ended September 29, 2018 and September 30, 2017 . Principles of Consolidation —The consolidated financial statements include the accounts of Summit LLC and its majority owned subsidiaries. All intercompany balances and transactions have been eliminated. The Company attributes consolidated member’s interest and net income separately to the controlling and noncontrolling interests. The Company accounts for investments in entities for which it has an ownership of 20% to 50% using the equity method of accounting. In October 2017, the Company acquired the 20% of Ohio Valley Asphalt, LLC held by noncontrolling interests, making it a wholly-owned subsidiary. 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 those states, as well as specific situations affecting individual customers. Credit granted within the Company’s trade areas has been extended 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 and nine months ended September 29, 2018 and September 30, 2017 . 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. Aggregates and cement products are sold point-of-sale through purchase orders. When the product is sold on account, collectability typically occurs 30 to 60 days after the sale. Revenue is recognized when cash is received from the customer at the point of sale or when the products are delivered or collected on site. There are no other timing implications that will create a contract asset or liability, and contract modifications are unlikely given the timing and nature of the transaction. Material sales are likely to have multiple performance obligations if the product is sold with delivery. In these instances, delivery most often occurs on the same day as the control of the product transfers to the customer. As a result, even in the case of multiple performance obligations, the performance obligations are satisfied concurrently and revenue is recognized simultaneously. 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. Collectability of service contracts is due reasonably after certain milestones in the contract are performed. Milestones vary by project, but are typically calculated using monthly progress based on the percentage of completion or a customer’s engineer review of progress. The majority of the time, collection occurs within 90 days of billing and cash is received within the same fiscal year as services performed. On most projects, the customer will withhold a portion of the invoice for retainage, which may last longer than a year depending on the job. 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 and nine months ended September 29, 2018 . We recognize claims when the amount of the claim can be estimated reliably and its realization is probable. In evaluating these criteria, we consider the contractual basis for the claim, the cause of any additional costs incurred, the reasonableness of those costs and the objective evidence available to support the claim. When the contract includes variable consideration, we estimate the amount of consideration to which we will be entitled in exchange for transferring the promised goods or services to a customer. The amount of estimated variable consideration included in the transaction price is the amount for which it is probable that a significant reversal in the amount of cumulative revenue recognized will not occur when the uncertainty associated with the variable consideration is subsequently resolved. Types of variable consideration include, but are not limited to, liquidated damages and other performance penalties and production and placement bonuses. The majority of contract modifications relate to the original contract and are often an extension of the original performance obligation. Predominately modifications are not distinct from the terms in the original contract; therefore, they are considered part of a single performance obligation. We account for the modification using a cumulative catch-up adjustment. However, there are instances where goods or services in a modification are distinct from those transferred prior to the modification. In these situations, we account for the modifications as either a separate contract or prospectively depending on the facts and circumstances of the modification. Generally, construction contracts contain mobilization costs which are categorized as costs to fulfill a contract. These costs are excluded from any measure of progress toward contract fulfillment. These costs do not result in the transfer of control of a good or service to the customer and are amortized over the life of the contract. 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 May 2014, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2014-09, Revenue from Contracts with Customers , which prescribes a five-step model for revenue recognition that replaced most existing revenue recognition guidance in U.S. GAAP. The ASU supersedes nearly all existing revenue recognition guidance under U.S. GAAP and provides that an entity recognize revenue when it transfers promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. This update also requires additional disclosure about the nature, amount, timing and uncertainty of revenue and cash flows arising from customer contracts, including significant judgments and changes in judgments, and assets recognized from costs incurred to obtain or fulfill a contract. In July 2015, the FASB postponed the effective date of the new revenue standard by one year to the first quarter of 2018. We adopted this ASU in the first quarter of 2018 using the modified retrospective approach, which did not have a material impact on our consolidated financial statements. In January 2017, the FASB issued ASU No. 2017-01, Clarifying the Definition of a Business, which narrows the definition of a business. This ASU provides a screen to determine whether a group of assets constitutes a business. The screen requires that when substantially all of the fair value of the gross assets acquired (or disposed of) is concentrated in a single identifiable asset or a group of similar identifiable assets, the set is not a business. This screen reduces the number of transactions that need to be further evaluated as acquisitions. If the screen is not met, this ASU (1) requires that to be considered a business, a set must include, at a minimum, an input and a substantive process that together significantly contribute to the ability to create an output and (2) removes the evaluation of whether a market participant could replace missing elements. Although outputs are not required for a set to be a business, outputs generally are a key element of a business; therefore, the FASB has developed more stringent criteria for sets without outputs. We adopted this ASU in the first quarter of 2018 and the adoption of this ASU did not have a material impact on the consolidated financial statements.

Acquisitions and Dispositions

Acquisitions and Dispositions	9 Months Ended
	Sep. 29, 2018
Business Acquisition [Line Items]
Acquisitions and Dispositions	ACQUISITIONS AND DISPOSITIONS Since its formation, the Company has completed numerous acquisitions, 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. The following table summarizes the Company’s acquisitions by region and period: Nine months ended Year ended September 29, 2018 December 30, 2017 West 4 6 East (1) 6 8 _____________________________________________________________________________________________ (1) In addition, the Company acquired certain assets of a small ready-mix concrete operation in the second quarter of 2018. The purchase price allocation, primarily the valuation of property, plant and equipment for the 2018 acquisitions, as well as the 2017 acquisitions that occurred after September 30, 2017 , has not yet been finalized due to the recent timing of the acquisitions and status of the valuation of property, plant and equipment. The following table summarizes aggregated information regarding the fair values of the assets acquired and liabilities assumed as of the respective acquisition dates: Nine months ended Year ended September 29, 2018 December 30, 2017 Financial assets $ 14,275 $ 31,615 Inventories 19,607 8,300 Property, plant and equipment 94,576 160,975 Intangible assets 3,179 161 Other assets 1,264 4,200 Financial liabilities (11,914 ) (15,501 ) Other long-term liabilities (8,255 ) (17,610 ) Net assets acquired 112,732 172,140 Goodwill 106,504 247,536 Purchase price 219,236 419,676 Acquisition-related liabilities (8,342 ) (43,452 ) Other — (1,294 ) Net cash paid for acquisitions $ 210,894 $ 374,930 Changes in the carrying amount of goodwill, by reportable segment, from December 30, 2017 to September 29, 2018 are summarized as follows: West East Cement Total Balance, December 30, 2017 $ 526,290 $ 305,374 $ 204,656 $ 1,036,320 Acquisitions (1) 55,013 57,950 — 112,963 Foreign currency translation adjustments (1,695 ) — — (1,695 ) Balance, September 29, 2018 $ 579,608 $ 363,324 $ 204,656 $ 1,147,588 _____________________________________________________________________________________________ (1) Reflects goodwill from 2018 acquisitions and working capital adjustments from prior year acquisitions. The Company’s intangible assets are primarily composed of goodwill, lease agreements and reserve rights. The assets related to lease agreements reflect the submarket royalty rates paid under agreements, primarily for extracting aggregates. The values were determined as of the respective acquisition dates by a comparison of market-royalty rates. 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: September 29, 2018 December 30, 2017 Gross Carrying Amount Accumulated Amortization Net Carrying Amount Gross Carrying Amount Accumulated Amortization Net Carrying Amount Leases $ 19,068 $ (4,950 ) $ 14,118 $ 15,888 $ (4,178 ) $ 11,710 Reserve rights 6,234 (1,857 ) 4,377 6,234 (1,625 ) 4,609 Trade names 1,000 (833 ) 167 1,000 (758 ) 242 Other 409 (179 ) 230 409 (137 ) 272 Total intangible assets $ 26,711 $ (7,819 ) $ 18,892 $ 23,531 $ (6,698 ) $ 16,833 Amortization expense totaled $0.5 million and $1.1 million for the three and nine months ended September 29, 2018 , respectively, and $0.3 million and $1.0 million for the three and nine months ended September 30, 2017 , respectively. The estimated amortization expense for the intangible assets for each of the five years subsequent to September 29, 2018 is as follows: 2018 (three months) $ 412 2019 1,588 2020 1,511 2021 1,475 2022 1,482 2023 1,350 Thereafter 11,074 Total $ 18,892 In September 2018, the Company sold a non-core business in the West segment, resulting in cash proceeds of $21.6 million , and a total gain on the disposition of the business of $12.1 million .
Summit Materials, LLC
Business Acquisition [Line Items]
Acquisitions and Dispositions	ACQUISITIONS AND DISPOSITIONS Since its formation, the Company has completed numerous acquisitions, 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. The following table summarizes the Company’s acquisitions by region and period: Nine months ended Year ended September 29, December 30, 2018 2017 West 4 6 East (1) 6 8 _______________________________________________________________________ (1) In addition, the Company acquired certain assets of a small ready-mix concrete operation in the second quarter of 2018. The purchase price allocation, primarily the valuation of property, plant and equipment for the 2018 acquisitions, as well as the 2017 acquisitions that occurred after September 30, 2017 , has not yet been finalized due to the recent timing of the acquisitions and status of the valuation of property, plant and equipment. The following table summarizes aggregated information regarding the fair values of the assets acquired and liabilities assumed as of the respective acquisition dates: Nine months ended Year ended September 29, December 30, 2018 2017 Financial assets $ 14,275 $ 31,615 Inventories 19,607 8,300 Property, plant and equipment 94,576 160,975 Intangible assets 3,179 161 Other assets 1,264 4,200 Financial liabilities (11,914 ) (15,501 ) Other long-term liabilities (8,255 ) (17,610 ) Net assets acquired 112,732 172,140 Goodwill 106,504 247,536 Purchase price 219,236 419,676 Acquisition-related liabilities (8,342 ) (43,452 ) Other — (1,294 ) Net cash paid for acquisitions $ 210,894 $ 374,930 Changes in the carrying amount of goodwill, by reportable segment, from December 30, 2017 to September 29, 2018 are summarized as follows: West East Cement Total Balance, December 30, 2017 $ 527,290 $ 305,374 $ 204,656 $ 1,037,320 Acquisitions (1) 55,013 57,950 — 112,963 Foreign currency translation adjustments (1,695 ) — — (1,695 ) Balance, September 29, 2018 $ 580,608 $ 363,324 $ 204,656 $ 1,148,588 _______________________________________________________________________ (1) Reflects goodwill from 2018 acquisitions and working capital adjustments from prior year acquisitions. The Company’s intangible assets are primarily composed of goodwill, lease agreements and reserve rights. The assets related to lease agreements reflect the submarket royalty rates paid under agreements, primarily for extracting aggregates. The values were determined as of the respective acquisition dates by a comparison of market-royalty rates. 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: September 29, 2018 December 30, 2017 Gross Carrying Amount Accumulated Amortization Net Carrying Amount Gross Carrying Amount Accumulated Amortization Net Carrying Amount Leases $ 19,068 $ (4,950 ) $ 14,118 $ 15,888 $ (4,178 ) $ 11,710 Reserve rights 6,234 (1,857 ) 4,377 6,234 (1,625 ) 4,609 Trade names 1,000 (833 ) 167 1,000 (758 ) 242 Other 409 (179 ) 230 409 (137 ) 272 Total intangible assets $ 26,711 $ (7,819 ) $ 18,892 $ 23,531 $ (6,698 ) $ 16,833 Amortization expense totaled $0.5 million and $1.1 million for the three and nine months ended September 29, 2018 , respectively, and $0.3 million and $1.0 million for the three and nine months ended September 30, 2017 , respectively. The estimated amortization expense for the intangible assets for each of the five years subsequent to September 29, 2018 is as follows: 2018 (three months) $ 412 2019 1,588 2020 1,511 2021 1,475 2022 1,482 2023 1,350 Thereafter 11,074 Total $ 18,892 In September 2018, the Company sold a non-core business in the West segment, resulting in cash proceeds of $21.6 million , and a total gain on the disposition of the business of $12.1 million .

Revenue Recognition

Revenue Recognition	9 Months Ended
	Sep. 29, 2018
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 and nine months ended September 29, 2018 and September 30, 2017 is as follows: Three months ended Nine months ended September 29, 2018 September 30, 2017 September 29, 2018 September 30, 2017 Revenue by product*: Aggregates $ 109,621 $ 90,594 $ 280,761 $ 236,437 Cement 87,909 94,915 197,439 213,243 Ready-mix concrete 164,866 139,934 447,490 361,824 Asphalt 125,153 115,917 231,666 218,934 Paving and related services 146,477 136,445 288,119 270,449 Other 60,635 56,376 164,497 141,664 Total revenue $ 694,661 $ 634,181 $ 1,609,972 $ 1,442,551 *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 30, 2017 to September 29, 2018 . 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 30, 2017 $ 9,512 $ 15,750 Changes in revenue billed, contract price or cost estimates 37,643 (3,850 ) Acquisitions 483 1,179 Other (9 ) (7 ) Balance - September 29, 2018 $ 47,629 $ 13,072 Accounts receivable, net consisted of the following as of September 29, 2018 and December 30, 2017 : September 29, 2018 December 30, 2017 Trade accounts receivable $ 220,540 $ 137,696 Construction contract receivables 70,626 49,832 Retention receivables 15,144 14,973 Receivables from related parties 297 468 Accounts receivable 306,607 202,969 Less: Allowance for doubtful accounts (4,937 ) (4,639 ) Accounts receivable, net $ 301,670 $ 198,330 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 and nine months ended September 29, 2018 and September 30, 2017 is as follows: Three months ended Nine months ended September 29, September 30, September 29, September 30, 2018 2017 2018 2017 Revenue by product*: Aggregates $ 109,621 $ 90,594 $ 280,761 $ 236,437 Cement 87,909 94,915 197,439 213,243 Ready-mix concrete 164,866 139,934 447,490 361,824 Asphalt 125,153 115,917 231,666 218,934 Paving and related services 146,477 136,445 288,119 270,449 Other 60,635 56,376 164,497 141,664 Total revenue $ 694,661 $ 634,181 $ 1,609,972 $ 1,442,551 *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 30, 2017 to September 29, 2018 . 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 30, 2017 $ 9,512 $ 15,750 Changes in revenue billed, contract price or cost estimates 37,643 (3,850 ) Acquisitions 483 1,179 Other (9 ) (7 ) Balance - September 29, 2018 $ 47,629 $ 13,072 Accounts receivable, net consisted of the following as of September 29, 2018 and December 30, 2017 : September 29, December 30, 2018 2017 Trade accounts receivable $ 220,540 $ 137,696 Construction contract receivables 70,626 49,832 Retention receivables 15,144 14,973 Receivables from related parties 297 468 Accounts receivable 306,607 202,969 Less: Allowance for doubtful accounts (4,937 ) (4,639 ) Accounts receivable, net $ 301,670 $ 198,330 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	9 Months Ended
	Sep. 29, 2018
Inventory [Line Items]
Inventories	INVENTORIES Inventories consisted of the following as of September 29, 2018 and December 30, 2017 : September 29, 2018 December 30, 2017 Aggregate stockpiles $ 158,476 $ 126,791 Finished goods 37,917 34,667 Work in process 10,028 7,729 Raw materials 23,340 15,252 Total $ 229,761 $ 184,439
Summit Materials, LLC
Inventory [Line Items]
Inventories	INVENTORIES Inventories consisted of the following as of September 29, 2018 and December 30, 2017 : September 29, 2018 December 30, 2017 Aggregate stockpiles $ 158,476 $ 126,791 Finished goods 37,917 34,667 Work in process 10,028 7,729 Raw materials 23,340 15,252 Total $ 229,761 $ 184,439

Accrued Expenses

Accrued Expenses	9 Months Ended
	Sep. 29, 2018
Schedule Of Accrued Expenses [Line Items]
Accrued Expenses	ACCRUED EXPENSES Accrued expenses consisted of the following as of September 29, 2018 and December 30, 2017 : September 29, 2018 December 30, 2017 Interest $ 23,267 $ 24,095 Payroll and benefits 25,569 33,915 Capital lease obligations 14,955 19,276 Insurance 14,580 11,455 Non-income taxes 14,634 7,236 Professional fees 960 1,717 Other (1) 20,292 18,935 Total $ 114,257 $ 116,629 (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 September 29, 2018 and December 30, 2017 : September 29, 2018 December 30, 2017 Interest $ 23,267 $ 24,095 Payroll and benefits 25,569 33,915 Capital lease obligations 14,955 19,276 Insurance 14,580 11,455 Non-income taxes 14,865 7,467 Professional fees 960 1,717 Other (1) 20,292 18,349 Total $ 114,488 $ 116,274 _______________________________________________________________________ (1) Consists primarily of subcontractor and working capital settlement accruals.

Debt

Debt	9 Months Ended
	Sep. 29, 2018
Debt Instrument [Line Items]
Debt	DEBT Debt consisted of the following as of September 29, 2018 and December 30, 2017 : September 29, 2018 December 30, 2017 Term Loan, due 2024: $630.6 million and $635.4 million, net of $1.4 million and $1.6 million discount at September 29, 2018 and December 30, 2017, respectively $ 629,210 $ 633,805 8 1 ⁄ 2 % Senior Notes, due 2022 250,000 250,000 6 1 ⁄ 8 % Senior Notes, due 2023: $650.0 million, net of $1.2 million and $1.4 million discount at September 29, 2018 and December 30, 2017, respectively 648,831 648,650 5 1 ⁄ 8 % Senior Notes, due 2025 300,000 300,000 Total 1,828,041 1,832,455 Current portion of long-term debt 4,765 4,765 Long-term debt $ 1,823,276 $ 1,827,690 The contractual payments of long-term debt, including current maturities, for the five years subsequent to September 29, 2018 , are as follows: 2018 (three months) $ — 2019 6,354 2020 7,942 2021 6,354 2022 256,354 2023 656,354 Thereafter 897,252 Total 1,830,610 Less: Original issue net discount (2,569 ) Less: Capitalized loan costs (15,086 ) Total debt $ 1,812,955 Senior Notes —On June 1, 2017, Summit LLC and Summit Finance (together, 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 2016, the Issuers issued $250.0 million of 8.500% senior notes due April 15, 2022 (the “2022 Notes”). The 2022 Notes were issued at 100.0% of their par value with proceeds of $246.3 million , net of related fees and expenses. The 2022 Notes were issued under an indenture dated March 8, 2016, the terms of which are generally consistent with the 2017 Indenture. Interest on the 2022 Notes is payable semi-annually in arrears on April 15 and October 15 of each year. In 2015, the Issuers issued $650.0 million of 6.125% senior notes due July 2023 (the “2023 Notes” and collectively with the 2022 Notes and the 2025 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 September 29, 2018 and December 30, 2017 , 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 $235.0 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 January 19, 2017, Summit LLC entered into Amendment No. 1 (“Amendment No. 1”) to the credit agreement governing the Senior Secured Credit Facilities (the “Credit Agreement”), which, among other things, reduced the applicable margin in respect of the then outstanding $640.3 million principal amount of term loans thereunder. All other material terms and provisions remain substantially identical to the terms and provisions in place immediately prior to the effectiveness of Amendment No. 1. On November 21, 2017, Summit LLC entered into Amendment No. 2 to the Credit Agreement, which, among other things, extended the maturity date from 2022 to 2024 and reduced the applicable margin in respect of the $635.4 million outstanding principal amount of term loans thereunder. On May 22, 2018, Summit LLC entered into Amendment No. 3 to the Credit Agreement, which, among other things, reduced the applicable margin in respect of the $633.8 million outstanding principal amount of term loans thereunder. The revolving credit facility bears interest per annum equal to, at Summit LLC’s option, either (i) a base rate determined by reference to the highest of (a) the federal funds rate plus 0.50% , (b) the prime rate of Bank of America, N.A. and (c) LIBOR plus 1.00% , plus an applicable margin of 2.25% for base rate loans or (ii) a LIBOR rate determined by reference to Reuters prior to the interest period relevant to such borrowing adjusted for certain additional costs plus an applicable margin of 3.00% for LIBOR rate loans. There were no outstanding borrowings under the revolving credit facility as of September 29, 2018 and December 30, 2017 , leaving remaining borrowing capacity of $219.6 million as of September 29, 2018 , which is net of $15.4 million of outstanding letters of credit. The outstanding letters of credit are renewed annually and support required bonding on construction projects and the Company’s insurance liabilities. Summit LLC’s Consolidated First Lien Net Leverage Ratio, as such term is defined in the Credit Agreement, should be no greater than 4.75 : 1.0 as of each quarter-end. As of September 29, 2018 and December 30, 2017 , 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 nine months ended September 29, 2018 and September 30, 2017 : Deferred financing fees Balance - December 30, 2017 $ 19,033 Loan origination fees 550 Amortization (3,074 ) Balance - September 29, 2018 $ 16,509 Balance - December 31, 2016 $ 18,290 Loan origination fees 5,317 Amortization (2,945 ) Write off of deferred financing fees (45 ) Balance - September 30, 2017 $ 20,617 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 September 29, 2018 or December 30, 2017 .
Summit Materials, LLC
Debt Instrument [Line Items]
Debt	DEBT Debt consisted of the following as of September 29, 2018 and December 30, 2017 : September 29, 2018 December 30, 2017 Term Loan, due 2024: $630.6 million and $635.4 million, net of $1.4 million and $1.6 million discount at September 29, 2018 and December 30, 2017, respectively $ 629,210 $ 633,805 8 1/2 % Senior Notes, due 2022 250,000 250,000 6 1/8 % Senior Notes, due 2023: $650.0 million, net of $1.2 million and $1.4 million discount at September 29, 2018 and December 30, 2017, respectively 648,831 648,650 5 1⁄8 % Senior Notes, due 2025 300,000 300,000 Total 1,828,041 1,832,455 Current portion of long-term debt 4,765 4,765 Long-term debt $ 1,823,276 $ 1,827,690 The contractual payments of long-term debt, including current maturities, for the five years subsequent to September 29, 2018 , are as follows: 2018 (three months) $ — 2019 6,354 2020 7,942 2021 6,354 2022 256,354 2023 656,354 Thereafter 897,252 Total 1,830,610 Less: Original issue net discount (2,569 ) Less: Capitalized loan costs (15,086 ) Total debt $ 1,812,955 Senior Notes —On June 1, 2017, 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 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 2016, the Issuers issued $250.0 million of 8.500% senior notes due April 15, 2022 (the “2022 Notes”). The 2022 Notes were issued at 100.0% of their par value with proceeds of $246.3 million , net of related fees and expenses. The 2022 Notes were issued under an indenture dated March 8, 2016, the terms of which are generally consistent with the 2017 Indenture. Interest on the 2022 Notes is payable semi-annually in arrears on April 15 and October 15 of each year. In 2015, the Issuers issued $650.0 million of 6.125% senior notes due July 2023 (the “2023 Notes” and collectively with the 2022 Notes and the 2025 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 September 29, 2018 and December 30, 2017 , 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 $235.0 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 January 19, 2017, Summit LLC entered into Amendment No. 1 (“Amendment No. 1”) to the credit agreement governing the Senior Secured Credit Facilities (the “Credit Agreement”), which, among other things, reduced the applicable margin in respect of the then outstanding $640.3 million principal amount of term loans thereunder. All other material terms and provisions remain substantially identical to the terms and provisions in place immediately prior to the effectiveness of Amendment No. 1. On November 21, 2017, Summit LLC entered into Amendment No. 2 to the Credit Agreement, which, among other things, extended the maturity date from 2022 to 2024 and reduced the applicable margin in respect of the $635.4 million outstanding principal amount of term loans thereunder. On May 22, 2018, Summit LLC entered into Amendment No. 3 to the Credit Agreement, which, among other things, reduced the applicable margin in respect of the $633.8 million outstanding principal amount of term loans thereunder. The revolving credit facility bears interest per annum equal to, at Summit LLC’s option, either (i) a base rate determined by reference to the highest of (a) the federal funds rate plus 0.50% , (b) the prime rate of Bank of America, N.A. and (c) LIBOR plus 1.00% , plus an applicable margin of 2.25% for base rate loans or (ii) a LIBOR rate determined by reference to Reuters prior to the interest period relevant to such borrowing adjusted for certain additional costs plus an applicable margin of 3.00% for LIBOR rate loans. There were no outstanding borrowings under the revolving credit facility as of September 29, 2018 and December 30, 2017 , leaving remaining borrowing capacity of $219.6 million as of September 29, 2018 , which is net of $15.4 million of outstanding letters of credit. The outstanding letters of credit are renewed annually and support required bonding on construction projects and the Company’s insurance liabilities. Summit LLC’s Consolidated First Lien Net Leverage Ratio, as such term is defined in the Credit Agreement, should be no greater than 4.75 :1.0 as of each quarter-end. As of September 29, 2018 and December 30, 2017 , 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 nine months ended September 29, 2018 and September 30, 2017 : Deferred financing fees Balance - December 30, 2017 $ 19,033 Loan origination fees 550 Amortization (3,074 ) Balance - September 29, 2018 $ 16,509 Balance - December 31, 2016 $ 18,290 Loan origination fees 5,317 Amortization (2,945 ) Write off of deferred financing fees (45 ) Balance - September 30, 2017 $ 20,617 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 September 29, 2018 or December 30, 2017 .

Income Taxes

Income Taxes	9 Months Ended
	Sep. 29, 2018
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 expense (benefit) was $20.8 million and $(498.3) million in the three months ended September 29, 2018 and September 30, 2017 , and our income tax expense (benefit) was $16.2 million and $(497.1) million in the nine months ended September 29, 2018 and September 30, 2017 , respectively. We recorded an income tax benefit in the three months ended September 30, 2017 primarily related to the release of the valuation allowance as discussed below, partially offset by an increase in the deferred tax liability of approximately $29.6 million . Our effective income tax rate in the third quarter of 2017 is not meaningful given the release of the valuation allowance against our deferred tax assets. For the three and nine months ended September 29, 2018 , 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 and (4) various other items such as limitations on meals and entertainment, certain stock compensation and other costs. For the three and nine months ended September 30, 2017 , the effective tax rate for Summit Inc. differs from the federal rate primarily due to (1) the change in valuation allowance, (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 and (4) various other items such as limitations on meals and entertainment, certain stock compensation and other costs. The ultimate realization of deferred tax assets is dependent upon the generation of future taxable income during the periods in which those temporary differences become deductible, as well as consideration of tax-planning strategies we may seek to utilize any net operating loss carryforwards scheduled to expire in the near future. In the nine months ended September 30, 2017, based on the increase in our cumulative income, and expectation of future income generation, we determined that our deferred tax assets had become more likely than not of being realized. As such, we released the majority of the valuation allowance that had previously been recorded against our deferred tax assets. Accordingly, we reduced the valuation allowance against our deferred tax assets by $532.0 million as of September 30, 2017. Our net operating loss carryforward deferred tax assets begin to expire in 2030 and are expected to reverse before expiration. Therefore, we have not given consideration to any potential tax planning strategies as a source of future taxable income to monetize those net operating loss carryforwards. The Company will continue to monitor facts and circumstances, including our analysis of other sources of taxable income, in the reassessment of the likelihood that the tax benefit of our deferred tax assets will be realized. As of September 29, 2018 and December 30, 2017 , Summit Inc. had a valuation allowance of $1.7 million , which relates to certain deferred tax assets in taxable entities where realization is not more likely than not. 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 nine months ended September 29, 2018 , 254,102 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 $2.2 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 September 29, 2018 and December 30, 2017 , we had recorded $333.2 million and $331.9 million of TRA liability of which $0.6 million was classified as accrued expenses as of December 30, 2017 . As a result of the analysis of the realizability of our deferred tax assets as of September 30, 2017 , we reduced the valuation allowance against our deferred tax assets, including those deferred tax assets subject to the TRA. Further, we determined the TRA liability to be probable of being payable and, as such, we recorded 85% of the deferred tax assets subject to the TRA, or $501.8 million , as TRA liability. 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 a portion of 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 the highest federal corporate tax rate plus the highest state and local tax rate in New York, New York. In the nine months ended September 29, 2018 and September 30, 2017 , we made tax distribution payments of $0.1 million and $0.1 million , respectively. As of September 29, 2018 and December 30, 2017 , Summit Inc. and its subsidiaries had not recognized any liabilities for uncertain tax positions. The Company records interest and penalties as a component of the income tax provision. No material interest or penalties were recognized in income tax expense during the three and nine months ended September 29, 2018 and September 30, 2017 .
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. As of September 29, 2018 and December 30, 2017 , the Company had not recognized any liabilities for uncertain tax positions. The Company records interest and penalties as a component of the income tax provision. No material interest or penalties were recognized in income tax expense during the three and nine months ended September 29, 2018 and September 30, 2017 .

Earnings Per Share

Earnings Per Share	9 Months Ended
	Sep. 29, 2018
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 earnings per share: Three months ended Nine months ended September 29, 2018 September 30, 2017 September 29, 2018 September 30, 2017 Net income attributable to Summit Inc. $ 71,289 $ 81,264 $ 53,069 $ 78,820 Weighted average shares of Class A stock outstanding 111,641,344 109,545,111 111,288,211 108,219,132 Basic income per share $ 0.64 $ 0.74 $ 0.48 $ 0.73 Diluted net income attributable to Summit Inc. $ 71,289 $ 81,264 $ 53,069 $ 78,820 Weighted average shares of Class A stock outstanding 111,641,344 109,545,111 111,288,211 108,219,132 Add: stock options 204,085 926,613 574,739 184,875 Add: warrants 18,631 39,555 34,134 42,094 Add: restricted stock units 4,515 220,531 402,950 285,088 Add: performance stock units 71,492 92,658 172,690 117,491 Weighted average dilutive shares outstanding 111,940,067 110,824,468 112,472,724 108,848,680 Diluted earnings per share $ 0.64 $ 0.73 $ 0.47 $ 0.72 Excluded from the above calculations were the shares noted below as they were antidilutive: Three months ended Nine months ended September 29, 2018 September 30, 2017 September 29, 2018 September 30, 2017 Antidilutive shares: LP Units 3,448,343 4,039,020 3,538,385 4,560,976

Stockholders' Equity_Members' I

Stockholders' Equity/Members' Interest	9 Months Ended
	Sep. 29, 2018
Schedule of Capitalization, Equity [Line Items]
Stockholders' Equity	STOCKHOLDERS’ EQUITY Equity Offering —On January 10, 2017, Summit Inc. raised $237.6 million , net of underwriting discounts, through the issuance of 10,000,000 shares of Class A common stock at a public offering price of $24.05 per share. Summit Inc. used these proceeds to purchase an equal number of LP Units. During 2017 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 30, 2017 110,350,594 3,689,620 114,040,214 96.8 % Exchanges during period 254,102 (254,102 ) — Other equity transactions 1,049,856 — 1,049,856 Balance - September 29, 2018 111,654,552 3,435,518 115,090,070 97.0 % Balance - December 31, 2016 97,554,278 5,151,297 102,705,575 95.0 % January 2017 public offering 10,000,000 — 10,000,000 Exchanges during period 1,255,266 (1,255,266 ) — Other equity transactions 1,177,200 — 1,177,200 Balance - September 30, 2017 109,986,744 3,896,031 113,882,775 96.6 % 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% and 3.2% as of September 29, 2018 and December 30, 2017 , respectively. 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 30, 2017 $ 2,364 $ 4,637 $ 385 $ 7,386 Foreign currency translation adjustment, net of tax — (2,295 ) — (2,295 ) Income on cash flow hedges, net of tax — — 1,043 1,043 Balance - September 29, 2018 $ 2,364 $ 2,342 $ 1,428 $ 6,134 Balance - December 31, 2016 $ 1,450 $ (3,106 ) $ (593 ) $ (2,249 ) Postretirement liability adjustment 397 — — 397 Foreign currency translation adjustment — 8,172 — 8,172 Income on cash flow hedges — — 368 368 Balance - September 30, 2017 $ 1,847 $ 5,066 $ (225 ) $ 6,688
Summit Materials, LLC
Schedule of Capitalization, Equity [Line Items]
Members' Interest	MEMBERS’ INTEREST Summit Inc.’s Equity Offering —On January 10, 2017, Summit Inc. raised $237.6 million , net of underwriting discounts, through the issuance of 10,000,000 shares of Class A common stock at a public offering price of $24.05 per share. Summit Inc. used these proceeds to purchase an equal number of LP Units. 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 30, 2017 $ (6,053 ) $ (10,022 ) $ (1,060 ) $ (17,135 ) Foreign currency translation adjustment — (3,179 ) — (3,179 ) Income on cash flow hedges — — 1,443 1,443 Balance - September 29, 2018 $ (6,053 ) $ (13,201 ) $ 383 $ (18,871 ) Balance - December 31, 2016 $ (7,181 ) $ (17,790 ) $ (2,473 ) $ (27,444 ) Postretirement liability adjustment 413 — — 413 Foreign currency translation adjustment — 8,498 — 8,498 Income on cash flow hedges — — 384 384 Balance - September 30, 2017 $ (6,768 ) $ (9,292 ) $ (2,089 ) $ (18,149 )

Supplemental Cash Flow Informat

Supplemental Cash Flow Information	9 Months Ended
	Sep. 29, 2018
Schedule Of Cash Flow Supplemental [Line Items]
Supplemental Cash Flow Information	SUPPLEMENTAL CASH FLOW INFORMATION Supplemental cash flow information is as follows: Nine months ended September 29, 2018 September 30, 2017 Cash payments: Interest $ 79,367 $ 71,117 Income taxes 3,362 1,841 Non cash financing activities: Exchange of LP Units to shares of Class A common stock 7,499 34,831
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: Nine months ended September 29, 2018 September 30, 2017 Cash payments: Interest $ 79,367 $ 71,117 Income taxes 3,362 1,841

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 29, 2018
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 pending or threatened claims and litigation will not have a material effect on the Company’s consolidated results of operations, financial position or liquidity. The Company records legal fees as incurred. 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 September 29, 2018 and December 30, 2017 , $24.5 million and $20.5 million , respectively, were included in other noncurrent liabilities on the consolidated balance sheets and $3.9 million and $3.9 million , respectively, were included in accrued expenses for future reclamation costs. The total undiscounted anticipated costs for site reclamation as of September 29, 2018 and December 30, 2017 were $84.0 million and $67.9 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 pending or threatened claims and litigation will not have a material effect on the Company’s consolidated results of operations, financial position or liquidity. The Company records legal fees as incurred. 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 September 29, 2018 and December 30, 2017 , $24.5 million and $20.5 million , respectively, were included in other noncurrent liabilities on the consolidated balance sheets and $3.9 million and $3.9 million , respectively, were included in accrued expenses for future reclamation costs. The total undiscounted anticipated costs for site reclamation as of September 29, 2018 and December 30, 2017 were $84.0 million and $67.9 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	9 Months Ended
	Sep. 29, 2018
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 September 29, 2018 and December 30, 2017 was: September 29, 2018 December 30, 2017 Current portion of acquisition-related liabilities and Accrued expenses: Contingent consideration $ 3,011 $ 594 Cash flow hedges — 488 Acquisition-related liabilities and Other noncurrent liabilities Contingent consideration $ 3,774 $ 34,301 Cash flow hedges — 492 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 September 29, 2018 and September 30, 2017 . 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 September 29, 2018 and December 30, 2017 was: September 29, 2018 December 30, 2017 Fair Value Carrying Value Fair Value Carrying Value Level 2 Long-term debt(1) $ 1,837,273 $ 1,828,041 $ 1,893,239 $ 1,832,455 Level 3 Current portion of deferred consideration and noncompete obligations(2) 11,137 11,137 13,493 13,493 Long term portion of deferred consideration and noncompete obligations(3) 25,355 25,355 23,834 23,834 (1) $4.8 million was included in current portion of debt as of September 29, 2018 and December 30, 2017 . (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 September 29, 2018 and December 30, 2017 was: September 29, 2018 December 30, 2017 Current portion of acquisition-related liabilities and Accrued expenses: Contingent consideration $ 3,011 $ 594 Cash flow hedges — 488 Acquisition-related liabilities and Other noncurrent liabilities Contingent consideration $ 3,774 $ 34,301 Cash flow hedges — 492 The fair value of contingent consideration was based on unobservable, or Level 3, inputs, including projected probability-weighted cash payments and a 10% 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 September 29, 2018 and September 30, 2017 . 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 September 29, 2018 and December 30, 2017 was: September 29, 2018 December 30, 2017 Fair Value Carrying Value Fair Value Carrying Value Level 2 Long-term debt(1) $ 1,837,273 $ 1,828,041 $ 1,893,239 $ 1,832,455 Level 3 Current portion of deferred consideration and noncompete obligations(2) 8,637 8,637 10,993 10,993 Long term portion of deferred consideration and noncompete obligations(3) 21,411 21,411 17,938 17,938 (1) $4.8 million was included in current portion of debt as of September 29, 2018 and December 30, 2017 . (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	9 Months Ended
	Sep. 29, 2018
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 September 29, 2018 and December 30, 2017 and for the three and nine months ended September 29, 2018 and September 30, 2017 : Three months ended Nine months ended September 29, 2018 September 30, 2017 September 29, 2018 September 30, 2017 Revenue*: West $ 367,912 $ 327,917 $ 871,338 $ 746,991 East 232,777 204,990 525,270 466,222 Cement 93,972 101,274 213,364 229,338 Total revenue $ 694,661 $ 634,181 $ 1,609,972 $ 1,442,551 *Intercompany sales are immaterial and the presentation above only reflects sales to external customers. Three months ended Nine months ended September 29, 2018 September 30, 2017 September 29, 2018 September 30, 2017 Income (loss) from operations before taxes $ 94,757 $ (414,046 ) $ 71,206 $ (415,809 ) Interest expense 28,889 28,921 86,616 79,876 Depreciation, depletion and amortization 53,494 48,483 149,439 132,374 Accretion 480 486 1,224 1,382 Loss on debt financings — — 149 190 Tax receivable agreement expense — 501,752 — 503,277 Gain on sale of business (12,108 ) — (12,108 ) — Transaction costs 1,260 2,581 3,817 6,474 Non-cash compensation 5,643 4,724 19,833 14,148 Other (409 ) (200 ) (7,316 ) (346 ) Total Adjusted EBITDA $ 172,006 $ 172,701 $ 312,860 $ 321,566 Total Adjusted EBITDA by Segment: West $ 73,916 $ 76,637 $ 151,316 $ 152,856 East 58,305 56,397 100,497 99,511 Cement 44,299 46,860 82,626 93,328 Corporate and other (4,514 ) (7,193 ) (21,579 ) (24,129 ) Total Adjusted EBITDA $ 172,006 $ 172,701 $ 312,860 $ 321,566 Nine months ended September 29, 2018 September 30, 2017 Purchases of property, plant and equipment West $ 104,217 $ 64,257 East 51,968 52,920 Cement 21,621 25,306 Total reportable segments 177,806 142,483 Corporate and other 5,946 4,995 Total purchases of property, plant and equipment $ 183,752 $ 147,478 Three months ended Nine months ended September 29, 2018 September 30, 2017 September 29, 2018 September 30, 2017 Depreciation, depletion, amortization and accretion: West $ 23,289 $ 18,907 $ 68,029 $ 51,989 East 19,429 17,628 54,982 49,939 Cement 10,682 11,815 25,733 29,888 Total reportable segments 53,400 48,350 148,744 131,816 Corporate and other 574 619 1,919 1,940 Total depreciation, depletion, amortization and accretion $ 53,974 $ 48,969 $ 150,663 $ 133,756 September 29, 2018 December 30, 2017 Total assets: West $ 1,422,966 $ 1,225,463 East 1,229,567 1,035,609 Cement 899,077 870,652 Total reportable segments 3,551,610 3,131,724 Corporate and other 344,724 655,609 Total $ 3,896,334 $ 3,787,333
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 September 29, 2018 and December 30, 2017 and for the three and nine months ended September 29, 2018 and September 30, 2017 : Three months ended Nine months ended September 29, September 30, September 29, September 30, 2018 2017 2018 2017 Revenue*: West $ 367,912 $ 327,917 $ 871,338 $ 746,991 East 232,777 204,990 525,270 466,222 Cement 93,972 101,274 213,364 229,338 Total revenue $ 694,661 $ 634,181 $ 1,609,972 $ 1,442,551 *Intercompany sales are immaterial and the presentation above only reflects sales to external customers. Three months ended Nine months ended September 29, September 30, September 29, September 30, 2018 2017 2018 2017 Income from operations before taxes $ 94,926 $ 87,919 $ 71,756 $ 88,149 Interest expense 28,720 28,708 86,066 79,195 Depreciation, depletion and amortization 53,494 48,483 149,439 132,374 Accretion 480 486 1,224 1,382 Loss on debt financings — — 149 190 Gain on sale of business (12,108 ) — (12,108 ) — Transaction costs 1,260 2,581 3,817 6,474 Non-cash compensation 5,643 4,724 19,833 14,148 Other (409 ) (200 ) (7,316 ) (346 ) Total Adjusted EBITDA $ 172,006 $ 172,701 $ 312,860 $ 321,566 Total Adjusted EBITDA by Segment: West $ 73,916 $ 76,637 $ 151,316 $ 152,856 East 58,305 56,397 100,497 99,511 Cement 44,299 46,860 82,626 93,328 Corporate and other (4,514 ) (7,193 ) (21,579 ) (24,129 ) Total Adjusted EBITDA $ 172,006 $ 172,701 $ 312,860 $ 321,566 Nine months ended September 29, 2018 September 30, 2017 Purchases of property, plant and equipment West $ 104,217 $ 64,257 East 51,968 52,920 Cement 21,621 25,306 Total reportable segments 177,806 142,483 Corporate and other 5,946 4,995 Total purchases of property, plant and equipment $ 183,752 $ 147,478 Three months ended Nine months ended September 29, September 30, September 29, September 30, 2018 2017 2018 2017 Depreciation, depletion, amortization and accretion: West $ 23,289 $ 18,907 $ 68,029 $ 51,989 East 19,429 17,628 54,982 49,939 Cement 10,682 11,815 25,733 29,888 Total reportable segments 53,400 48,350 148,744 131,816 Corporate and other 574 619 1,919 1,940 Total depreciation, depletion, amortization and accretion $ 53,974 $ 48,969 $ 150,663 $ 133,756 September 29, 2018 December 30, 2017 Total assets: West $ 1,422,966 $ 1,225,463 East 1,229,567 1,035,609 Cement 899,077 870,652 Total reportable segments 3,551,610 3,131,724 Corporate and other 78,192 372,517 Total $ 3,629,802 $ 3,504,241

Guarantor and Non-Guarantor Fin

Guarantor and Non-Guarantor Financial Information	9 Months Ended
	Sep. 29, 2018
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 September 29, 2018 100% Owned Non- Issuers Guarantors Guarantors Eliminations Consolidated Assets Current assets: Cash and cash equivalents $ 75,529 $ 1,946 $ 3,707 $ (16,252 ) $ 64,930 Accounts receivable, net 289 279,071 22,489 (179 ) 301,670 Intercompany receivables 523,663 509,313 — (1,032,976 ) — Cost and estimated earnings in excess of billings — 45,732 1,897 — 47,629 Inventories — 227,047 2,714 — 229,761 Other current assets 1,758 12,986 946 — 15,690 Total current assets 601,239 1,076,095 31,753 (1,049,407 ) 659,680 Property, plant and equipment, net 12,556 1,678,923 60,331 — 1,751,810 Goodwill — 1,089,169 59,419 — 1,148,588 Intangible assets, net — 18,892 — — 18,892 Other assets 3,219,616 160,131 1,449 (3,330,364 ) 50,832 Total assets $ 3,833,411 $ 4,023,210 $ 152,952 $ (4,379,771 ) $ 3,629,802 Liabilities and Member’s Interest Current liabilities: Current portion of debt $ 4,765 $ — $ — $ — $ 4,765 Current portion of acquisition-related liabilities — 11,648 — — 11,648 Accounts payable 4,580 121,519 15,560 (179 ) 141,480 Accrued expenses 42,095 85,922 2,723 (16,252 ) 114,488 Intercompany payables 580,768 438,378 13,830 (1,032,976 ) — Billings in excess of costs and estimated earnings — 12,417 655 — 13,072 Total current liabilities 632,208 669,884 32,768 (1,049,407 ) 285,453 Long-term debt 1,808,190 — — — 1,808,190 Acquisition-related liabilities — 25,185 — — 25,185 Other noncurrent liabilities 3,756 213,054 76,225 (171,318 ) 121,717 Total liabilities 2,444,154 908,123 108,993 (1,220,725 ) 2,240,545 Total member's interest 1,389,257 3,115,087 43,959 (3,159,046 ) 1,389,257 Total liabilities and member’s interest $ 3,833,411 $ 4,023,210 $ 152,952 $ (4,379,771 ) $ 3,629,802 Condensed Consolidating Balance Sheets December 30, 2017 100% Owned Non- Issuers Guarantors Guarantors Eliminations Consolidated Assets Current assets: Cash and cash equivalents $ 370,741 $ 10,254 $ 14,933 $ (12,372 ) $ 383,556 Accounts receivable, net — 183,139 15,191 — 198,330 Intercompany receivables 573,301 484,747 — (1,058,048 ) — Cost and estimated earnings in excess of billings — 9,264 248 — 9,512 Inventories — 180,283 4,156 — 184,439 Other current assets 1,167 6,354 243 — 7,764 Total current assets 945,209 874,041 34,771 (1,070,420 ) 783,601 Property, plant and equipment, net 9,259 1,569,118 37,047 — 1,615,424 Goodwill — 976,206 61,114 — 1,037,320 Intangible assets, net — 16,833 — — 16,833 Other assets 2,890,674 162,711 1,271 (3,003,593 ) 51,063 Total assets $ 3,845,142 $ 3,598,909 $ 134,203 $ (4,074,013 ) $ 3,504,241 Liabilities and Member’s Interest Current liabilities: Current portion of debt $ 4,765 $ — $ — $ — $ 4,765 Current portion of acquisition-related liabilities — 11,587 — — 11,587 Accounts payable 3,976 89,912 6,749 — 100,637 Accrued expenses 47,047 79,372 2,227 (12,372 ) 116,274 Intercompany payables 684,057 369,918 4,073 (1,058,048 ) — Billings in excess of costs and estimated earnings — 15,349 401 — 15,750 Total current liabilities 739,845 566,138 13,450 (1,070,420 ) 249,013 Long-term debt 1,810,833 — — — 1,810,833 Acquisition-related liabilities — 52,239 — — 52,239 Other noncurrent liabilities 2,870 193,801 75,209 (171,318 ) 100,562 Total liabilities 2,553,548 812,178 88,659 (1,241,738 ) 2,212,647 Total member's interest 1,291,594 2,786,731 45,544 (2,832,275 ) 1,291,594 Total liabilities and member’s interest $ 3,845,142 $ 3,598,909 $ 134,203 $ (4,074,013 ) $ 3,504,241 Condensed Consolidating Statements of Operations For the three months ended September 29, 2018 100% Owned Non- Issuers Guarantors Guarantors Eliminations Consolidated Revenue $ — $ 668,145 $ 28,064 $ (1,548 ) $ 694,661 Cost of revenue (excluding items shown separately below) — 452,394 20,957 (1,548 ) 471,803 General and administrative expenses 10,951 46,910 2,856 — 60,717 Depreciation, depletion, amortization and accretion 574 52,213 1,187 — 53,974 Operating (loss) income (11,525 ) 116,628 3,064 — 108,167 Other income, net (132,382 ) (3,019 ) (236 ) 132,266 (3,371 ) Interest expense (income) 29,396 (1,882 ) 1,206 — 28,720 Gain on sale of business — (12,108 ) — — (12,108 ) Income from operations before taxes 91,461 133,637 2,094 (132,266 ) 94,926 Income tax expense 1,034 2,898 567 — 4,499 Net income attributable to member of Summit Materials, LLC $ 90,427 $ 130,739 $ 1,527 $ (132,266 ) $ 90,427 Comprehensive income (loss) attributable to member of Summit Materials, LLC $ 92,484 $ 130,652 $ (443 ) $ (130,209 ) $ 92,484 Condensed Consolidating Statements of Operations For the nine months ended September 29, 2018 100% Owned Non- Issuers Guarantors Guarantors Eliminations Consolidated Revenue $ — $ 1,548,960 $ 65,597 $ (4,585 ) $ 1,609,972 Cost of revenue (excluding items shown separately below) — 1,087,150 48,031 (4,585 ) 1,130,596 General and administrative expenses 45,175 141,372 8,245 — 194,792 Depreciation, depletion, amortization and accretion 1,919 145,135 3,609 — 150,663 Operating (loss) income (47,094 ) 175,303 5,712 — 133,921 Other (income) loss, net (204,677 ) (10,563 ) (87 ) 203,534 (11,793 ) Interest expense (income) 87,924 (5,447 ) 3,589 — 86,066 Gain on sale of business — (12,108 ) — — (12,108 ) Income from operations before taxes 69,659 203,421 2,210 (203,534 ) 71,756 Income tax expense 1,226 1,481 616 — 3,323 Net income attributable to member of Summit Materials, LLC $ 68,433 $ 201,940 $ 1,594 $ (203,534 ) $ 68,433 Comprehensive income attributable to member of Summit Materials, LLC $ 66,697 $ 200,497 $ 4,773 $ (205,270 ) $ 66,697 Condensed Consolidating Statements of Operations For the three months ended September 30, 2017 100% Owned Non- Issuers Guarantors Guarantors Eliminations Consolidated Revenue $ — $ 606,046 $ 29,608 $ (1,473 ) $ 634,181 Cost of revenue (excluding items shown separately below) — 389,716 21,302 (1,473 ) 409,545 General and administrative expenses 15,011 44,373 2,372 — 61,756 Depreciation, depletion, amortization and accretion 619 47,032 1,318 — 48,969 Operating (loss) income (15,630 ) 124,925 4,616 — 113,911 Other income, net (126,386 ) (1,569 ) (245 ) 125,484 (2,716 ) Interest expense (income) 28,182 (670 ) 1,196 — 28,708 Income from operations before taxes 82,574 127,164 3,665 (125,484 ) 87,919 Income tax expense — 4,397 889 — 5,286 Net income 82,574 122,767 2,776 (125,484 ) 82,633 Net income attributable to noncontrolling interest — — — 59 59 Net income attributable to member of Summit Materials, LLC $ 82,574 $ 122,767 $ 2,776 $ (125,543 ) $ 82,574 Comprehensive income (loss) attributable to member of Summit Materials, LLC $ 87,160 $ 122,555 $ (1,598 ) $ (120,957 ) $ 87,160 Condensed Consolidating Statements of Operations For the nine months ended September 30, 2017 100% Owned Non- Issuers Guarantors Guarantors Eliminations Consolidated Revenue $ — $ 1,384,956 $ 62,230 $ (4,635 ) $ 1,442,551 Cost of revenue (excluding items shown separately below) — 922,024 45,632 (4,635 ) 963,021 General and administrative expenses 44,718 131,770 5,715 — 182,203 Depreciation, depletion, amortization and accretion 1,940 128,851 2,965 — 133,756 Operating (loss) income (46,658 ) 202,311 7,918 — 163,571 Other income, net (204,877 ) (1,561 ) (500 ) 203,165 (3,773 ) Interest expense (income) 76,586 (533 ) 3,142 — 79,195 Income from operations before taxes 81,633 204,405 5,276 (203,165 ) 88,149 Income tax expense — 5,119 1,424 — 6,543 Net income 81,633 199,286 3,852 (203,165 ) 81,606 Net loss attributable to noncontrolling interest — — — (27 ) (27 ) Net income attributable to member of Summit Materials, LLC $ 81,633 $ 199,286 $ 3,852 $ (203,138 ) $ 81,633 Comprehensive income (loss) attributable to member of Summit Materials, LLC $ 90,928 $ 198,489 $ (4,646 ) $ (193,843 ) $ 90,928 Condensed Consolidating Statements of Cash Flows For the nine months ended September 29, 2018 100% Owned Non- Issuers Guarantors Guarantors Eliminations Consolidated Net cash (used in) provided by operating activities $ (107,736 ) $ 173,597 $ 4,696 $ — $ 70,557 Cash flow from investing activities: Acquisitions, net of cash acquired — (210,894 ) — — (210,894 ) Purchase of property, plant and equipment (5,946 ) (156,016 ) (21,790 ) — (183,752 ) Proceeds from the sale of property, plant, and equipment — 18,257 169 — 18,426 Proceeds from the sale of a business — 21,564 — — 21,564 Other — 2,660 — — 2,660 Net cash used for investing activities (5,946 ) (324,429 ) (21,621 ) — (351,996 ) Cash flow from financing activities: Proceeds from investment by member (112,386 ) 128,001 — — 15,615 Net proceeds from debt issuance 64,500 — — — 64,500 Loans received from and payments made on loans from other Summit Companies (60,387 ) 58,052 6,215 (3,880 ) — Payments on long-term debt (69,265 ) (9,701 ) (61 ) — (79,027 ) Payments on acquisition-related liabilities — (32,821 ) — — (32,821 ) Debt issuance costs (550 ) — — — (550 ) Distributions from partnership (2,569 ) — — — (2,569 ) Other (873 ) (1,007 ) (33 ) — (1,913 ) Net cash (used in) provided by financing activities (181,530 ) 142,524 6,121 (3,880 ) (36,765 ) Impact of cash on foreign currency — — (422 ) — (422 ) Net decrease in cash (295,212 ) (8,308 ) (11,226 ) (3,880 ) (318,626 ) Cash — Beginning of period 370,741 10,254 14,933 (12,372 ) 383,556 Cash — End of period $ 75,529 $ 1,946 $ 3,707 $ (16,252 ) $ 64,930 Condensed Consolidating Statements of Cash Flows For the nine months ended September 30, 2017 100% Owned Non- Issuers Guarantors Guarantors Eliminations Consolidated Net cash (used in) provided by operating activities $ (92,840 ) $ 198,890 $ 26,845 $ — $ 132,895 Cash flow from investing activities: Acquisitions, net of cash acquired (24,538 ) (321,340 ) (25,601 ) — (371,479 ) Purchase of property, plant and equipment (4,994 ) (137,505 ) (4,979 ) — (147,478 ) Proceeds from the sale of property, plant, and equipment — 13,231 59 — 13,290 Other — 182 — — 182 Net cash used for investing activities (29,532 ) (445,432 ) (30,521 ) — (505,485 ) Cash flow from financing activities: Proceeds from investment by member (3,409 ) 249,359 10,717 — 256,667 Capital issuance costs (627 ) — — — (627 ) Net proceeds from debt issuance 302,000 — — — 302,000 Loans received from and payments made on loans from other Summit Companies (10,787 ) 20,975 (6,282 ) (3,906 ) — Payments on long-term debt (6,874 ) (6,009 ) (4 ) — (12,887 ) Payments on acquisition-related liabilities — (20,116 ) — — (20,116 ) Financing costs (5,317 ) — — — (5,317 ) Distributions from partnership (2,609 ) — — — (2,609 ) Other (536 ) (288 ) (21 ) — (845 ) Net cash provided by financing activities 271,841 243,921 4,410 (3,906 ) 516,266 Impact of cash on foreign currency — — 734 — 734 Net increase (decrease) in cash 149,469 (2,621 ) 1,468 (3,906 ) 144,410 Cash — Beginning of period 133,862 4,820 14,656 (10,666 ) 142,672 Cash — End of period $ 283,331 $ 2,199 $ 16,124 $ (14,572 ) $ 287,082

Summary of Organization and S_2

Summary of Organization and Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 29, 2018
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 30, 2017 . 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 September 29, 2018 , the results of operations for the three and nine months ended September 29, 2018 and September 30, 2017 and cash flows for the nine months ended September 29, 2018 and September 30, 2017 .
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. The Company attributes consolidated stockholders’ equity and net income separately to the controlling and noncontrolling interests. The Company accounts for investments in entities for which it has an ownership of 20% to 50% using the equity method of accounting. In October 2017, the Company acquired the 20% of Ohio Valley Asphalt, LLC held by noncontrolling interests, making it a wholly owned subsidiary.
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 those states, as well as specific situations affecting individual customers. Credit granted within the Company’s trade areas has been extended 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 and nine months ended September 29, 2018 and September 30, 2017 .
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. Aggregates and cement products are sold point-of-sale through purchase orders. When the product is sold on account, collectability typically occurs 30 to 60 days after the sale. Revenue is recognized when cash is received from the customer at the point of sale or when the products are delivered or collected on site. There are no other timing implications that will create a contract asset or liability, and contract modifications are unlikely given the timing and nature of the transaction. Material sales are likely to have multiple performance obligations if the product is sold with delivery. In these instances, delivery most often occurs on the same day as the control of the product transfers to the customer. As a result, even in the case of multiple performance obligations, the performance obligations are satisfied concurrently and revenue is recognized simultaneously. 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. Collectability of service contracts is due reasonably after certain milestones in the contract are performed. Milestones vary by project, but are typically calculated using monthly progress based on the percentage of completion or a customer’s engineer review of progress. The majority of the time, collection occurs within 90 days of billing and cash is received within the same fiscal year as services performed. On most projects, the customer will withhold a portion of the invoice for retainage, which may last longer than a year depending on the job. 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 and nine months ended September 29, 2018 . We recognize claims when the amount of the claim can be estimated reliably and its realization is probable. In evaluating these criteria, we consider the contractual basis for the claim, the cause of any additional costs incurred, the reasonableness of those costs and the objective evidence available to support the claim. When the contract includes variable consideration, we estimate the amount of consideration to which we will be entitled in exchange for transferring the promised goods or services to a customer. The amount of estimated variable consideration included in the transaction price is the amount for which it is probable that a significant reversal in the amount of cumulative revenue recognized will not occur when the uncertainty associated with the variable consideration is subsequently resolved. Types of variable consideration include, but are not limited to, liquidated damages and other performance penalties and production and placement bonuses. The majority of contract modifications relate to the original contract and are often an extension of the original performance obligation. Predominately modifications are not distinct from the terms in the original contract; therefore, they are considered part of a single performance obligation. We account for the modification using a cumulative catch-up adjustment. However, there are instances where goods or services in a modification are distinct from those transferred prior to the modification. In these situations, we account for the modifications as either a separate contract or prospectively depending on the facts and circumstances of the modification. Generally, construction contracts contain mobilization costs which are categorized as costs to fulfill a contract. These costs are excluded from any measure of progress toward contract fulfillment. These costs do not result in the transfer of control of a good or service to the customer and are amortized over the life of the contract. 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 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 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.
Reclassifications	Reclassification — Within the operating activities section on the consolidated statement of cash flows for the nine month period ended September 30, 2017 , the Company reclassified $4.8 million from deferred income tax benefit, $ 17,000 from other current assets and $498.8 million from deferred tax assets, net, to change in deferred tax asset, net, to conform to the current year presentation.
New Accounting Standards	New Accounting Standards — In May 2014, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2014-09, Revenue from Contracts with Customers , which prescribes a five-step model for revenue recognition that replaced most existing revenue recognition guidance in U.S. GAAP. The ASU supersedes nearly all existing revenue recognition guidance under U.S. GAAP and provides that an entity recognize revenue when it transfers promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. This update also requires additional disclosure about the nature, amount, timing and uncertainty of revenue and cash flows arising from customer contracts, including significant judgments and changes in judgments, and assets recognized from costs incurred to obtain or fulfill a contract. In July 2015, the FASB postponed the effective date of the new revenue standard by one year to the first quarter of 2018. We adopted this ASU in the first quarter of 2018 using the modified retrospective approach, which did not have a material impact on our consolidated financial statements. In January 2017, the FASB issued ASU No. 2017-01, Clarifying the Definition of a Business, which narrows the definition of a business. This ASU provides a screen to determine whether a group of assets constitutes a business. The screen requires that when substantially all of the fair value of the gross assets acquired (or disposed of) is concentrated in a single identifiable asset or a group of similar identifiable assets, the set is not a business. This screen reduces the number of transactions that need to be further evaluated as acquisitions. If the screen is not met, this ASU (1) requires that to be considered a business, a set must include, at a minimum, an input and a substantive process that together significantly contribute to the ability to create an output and (2) removes the evaluation of whether a market participant could replace missing elements. Although outputs are not required for a set to be a business, outputs generally are a key element of a business; therefore, the FASB has developed more stringent criteria for sets without outputs. We adopted this ASU in the first quarter of 2018 and the adoption of this ASU did not have a material impact on the consolidated financial statements.
Summit Materials, LLC
Summary Of Significant Accounting Policies And Recent Accounting Pronouncements [Line Items]
Follow On Offering	Summit Inc. Equity Offering —On January 10, 2017, Summit Inc. raised $237.6 million , net of underwriting discounts, through the issuance of 10,000,000 shares of Class A common stock at a public offering price of $24.05 per share. Summit Inc. used these proceeds to purchase an equal number of limited partnership interests in Summit Holdings (“LP Units”) and caused Summit Holdings to use a portion of the proceeds from the offering to acquire two materials-based companies for a combined purchase price of approximately $110 million in cash.
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 30, 2017. 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 September 29, 2018 , the results of operations for the three and nine months ended September 29, 2018 and September 30, 2017 and cash flows for the nine months ended September 29, 2018 and September 30, 2017 .
Principles of Consolidation	Principles of Consolidation —The consolidated financial statements include the accounts of Summit LLC and its majority owned subsidiaries. All intercompany balances and transactions have been eliminated. The Company attributes consolidated member’s interest and net income separately to the controlling and noncontrolling interests. The Company accounts for investments in entities for which it has an ownership of 20% to 50% using the equity method of accounting. In October 2017, the Company acquired the 20% of Ohio Valley Asphalt, LLC held by noncontrolling interests, making it a wholly-owned subsidiary.
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 those states, as well as specific situations affecting individual customers. Credit granted within the Company’s trade areas has been extended 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 and nine months ended September 29, 2018 and September 30, 2017 .
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. Aggregates and cement products are sold point-of-sale through purchase orders. When the product is sold on account, collectability typically occurs 30 to 60 days after the sale. Revenue is recognized when cash is received from the customer at the point of sale or when the products are delivered or collected on site. There are no other timing implications that will create a contract asset or liability, and contract modifications are unlikely given the timing and nature of the transaction. Material sales are likely to have multiple performance obligations if the product is sold with delivery. In these instances, delivery most often occurs on the same day as the control of the product transfers to the customer. As a result, even in the case of multiple performance obligations, the performance obligations are satisfied concurrently and revenue is recognized simultaneously. 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. Collectability of service contracts is due reasonably after certain milestones in the contract are performed. Milestones vary by project, but are typically calculated using monthly progress based on the percentage of completion or a customer’s engineer review of progress. The majority of the time, collection occurs within 90 days of billing and cash is received within the same fiscal year as services performed. On most projects, the customer will withhold a portion of the invoice for retainage, which may last longer than a year depending on the job. 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 and nine months ended September 29, 2018 . We recognize claims when the amount of the claim can be estimated reliably and its realization is probable. In evaluating these criteria, we consider the contractual basis for the claim, the cause of any additional costs incurred, the reasonableness of those costs and the objective evidence available to support the claim. When the contract includes variable consideration, we estimate the amount of consideration to which we will be entitled in exchange for transferring the promised goods or services to a customer. The amount of estimated variable consideration included in the transaction price is the amount for which it is probable that a significant reversal in the amount of cumulative revenue recognized will not occur when the uncertainty associated with the variable consideration is subsequently resolved. Types of variable consideration include, but are not limited to, liquidated damages and other performance penalties and production and placement bonuses. The majority of contract modifications relate to the original contract and are often an extension of the original performance obligation. Predominately modifications are not distinct from the terms in the original contract; therefore, they are considered part of a single performance obligation. We account for the modification using a cumulative catch-up adjustment. However, there are instances where goods or services in a modification are distinct from those transferred prior to the modification. In these situations, we account for the modifications as either a separate contract or prospectively depending on the facts and circumstances of the modification. Generally, construction contracts contain mobilization costs which are categorized as costs to fulfill a contract. These costs are excluded from any measure of progress toward contract fulfillment. These costs do not result in the transfer of control of a good or service to the customer and are amortized over the life of the contract. 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 May 2014, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2014-09, Revenue from Contracts with Customers , which prescribes a five-step model for revenue recognition that replaced most existing revenue recognition guidance in U.S. GAAP. The ASU supersedes nearly all existing revenue recognition guidance under U.S. GAAP and provides that an entity recognize revenue when it transfers promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. This update also requires additional disclosure about the nature, amount, timing and uncertainty of revenue and cash flows arising from customer contracts, including significant judgments and changes in judgments, and assets recognized from costs incurred to obtain or fulfill a contract. In July 2015, the FASB postponed the effective date of the new revenue standard by one year to the first quarter of 2018. We adopted this ASU in the first quarter of 2018 using the modified retrospective approach, which did not have a material impact on our consolidated financial statements. In January 2017, the FASB issued ASU No. 2017-01, Clarifying the Definition of a Business, which narrows the definition of a business. This ASU provides a screen to determine whether a group of assets constitutes a business. The screen requires that when substantially all of the fair value of the gross assets acquired (or disposed of) is concentrated in a single identifiable asset or a group of similar identifiable assets, the set is not a business. This screen reduces the number of transactions that need to be further evaluated as acquisitions. If the screen is not met, this ASU (1) requires that to be considered a business, a set must include, at a minimum, an input and a substantive process that together significantly contribute to the ability to create an output and (2) removes the evaluation of whether a market participant could replace missing elements. Although outputs are not required for a set to be a business, outputs generally are a key element of a business; therefore, the FASB has developed more stringent criteria for sets without outputs. We adopted this ASU in the first quarter of 2018 and the adoption of this ASU did not have a material impact on the consolidated financial statements.

Acquisitions and Dispositions (

Acquisitions and Dispositions (Tables)	9 Months Ended
	Sep. 29, 2018
Business Acquisition [Line Items]
Summary of Acquisitions by Region	The following table summarizes the Company’s acquisitions by region and period: Nine months ended Year ended September 29, 2018 December 30, 2017 West 4 6 East (1) 6 8 _____________________________________________________________________________________________ (1) In addition, the Company acquired certain assets of a small ready-mix concrete operation in the second quarter of 2018.
Summary of Assets Acquired and Liabilities Assumed	The following table summarizes aggregated information regarding the fair values of the assets acquired and liabilities assumed as of the respective acquisition dates: Nine months ended Year ended September 29, 2018 December 30, 2017 Financial assets $ 14,275 $ 31,615 Inventories 19,607 8,300 Property, plant and equipment 94,576 160,975 Intangible assets 3,179 161 Other assets 1,264 4,200 Financial liabilities (11,914 ) (15,501 ) Other long-term liabilities (8,255 ) (17,610 ) Net assets acquired 112,732 172,140 Goodwill 106,504 247,536 Purchase price 219,236 419,676 Acquisition-related liabilities (8,342 ) (43,452 ) Other — (1,294 ) Net cash paid for acquisitions $ 210,894 $ 374,930
Goodwill by Reportable Segment and in Total	Changes in the carrying amount of goodwill, by reportable segment, from December 30, 2017 to September 29, 2018 are summarized as follows: West East Cement Total Balance, December 30, 2017 $ 526,290 $ 305,374 $ 204,656 $ 1,036,320 Acquisitions (1) 55,013 57,950 — 112,963 Foreign currency translation adjustments (1,695 ) — — (1,695 ) Balance, September 29, 2018 $ 579,608 $ 363,324 $ 204,656 $ 1,147,588 _____________________________________________________________________________________________ (1) Reflects goodwill from 2018 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: September 29, 2018 December 30, 2017 Gross Carrying Amount Accumulated Amortization Net Carrying Amount Gross Carrying Amount Accumulated Amortization Net Carrying Amount Leases $ 19,068 $ (4,950 ) $ 14,118 $ 15,888 $ (4,178 ) $ 11,710 Reserve rights 6,234 (1,857 ) 4,377 6,234 (1,625 ) 4,609 Trade names 1,000 (833 ) 167 1,000 (758 ) 242 Other 409 (179 ) 230 409 (137 ) 272 Total intangible assets $ 26,711 $ (7,819 ) $ 18,892 $ 23,531 $ (6,698 ) $ 16,833
Estimated Amortization Expense for Intangible Assets	The estimated amortization expense for the intangible assets for each of the five years subsequent to September 29, 2018 is as follows: 2018 (three months) $ 412 2019 1,588 2020 1,511 2021 1,475 2022 1,482 2023 1,350 Thereafter 11,074 Total $ 18,892 In September 2018, the Company sold a non-core business in the West segment, resulting in cash proceeds of $21.6 million , and a total gain on the disposition of the business of $12.1 million .
Acquisitions and Dispositions	ACQUISITIONS AND DISPOSITIONS Since its formation, the Company has completed numerous acquisitions, 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. The following table summarizes the Company’s acquisitions by region and period: Nine months ended Year ended September 29, 2018 December 30, 2017 West 4 6 East (1) 6 8 _____________________________________________________________________________________________ (1) In addition, the Company acquired certain assets of a small ready-mix concrete operation in the second quarter of 2018. The purchase price allocation, primarily the valuation of property, plant and equipment for the 2018 acquisitions, as well as the 2017 acquisitions that occurred after September 30, 2017 , has not yet been finalized due to the recent timing of the acquisitions and status of the valuation of property, plant and equipment. The following table summarizes aggregated information regarding the fair values of the assets acquired and liabilities assumed as of the respective acquisition dates: Nine months ended Year ended September 29, 2018 December 30, 2017 Financial assets $ 14,275 $ 31,615 Inventories 19,607 8,300 Property, plant and equipment 94,576 160,975 Intangible assets 3,179 161 Other assets 1,264 4,200 Financial liabilities (11,914 ) (15,501 ) Other long-term liabilities (8,255 ) (17,610 ) Net assets acquired 112,732 172,140 Goodwill 106,504 247,536 Purchase price 219,236 419,676 Acquisition-related liabilities (8,342 ) (43,452 ) Other — (1,294 ) Net cash paid for acquisitions $ 210,894 $ 374,930 Changes in the carrying amount of goodwill, by reportable segment, from December 30, 2017 to September 29, 2018 are summarized as follows: West East Cement Total Balance, December 30, 2017 $ 526,290 $ 305,374 $ 204,656 $ 1,036,320 Acquisitions (1) 55,013 57,950 — 112,963 Foreign currency translation adjustments (1,695 ) — — (1,695 ) Balance, September 29, 2018 $ 579,608 $ 363,324 $ 204,656 $ 1,147,588 _____________________________________________________________________________________________ (1) Reflects goodwill from 2018 acquisitions and working capital adjustments from prior year acquisitions. The Company’s intangible assets are primarily composed of goodwill, lease agreements and reserve rights. The assets related to lease agreements reflect the submarket royalty rates paid under agreements, primarily for extracting aggregates. The values were determined as of the respective acquisition dates by a comparison of market-royalty rates. 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: September 29, 2018 December 30, 2017 Gross Carrying Amount Accumulated Amortization Net Carrying Amount Gross Carrying Amount Accumulated Amortization Net Carrying Amount Leases $ 19,068 $ (4,950 ) $ 14,118 $ 15,888 $ (4,178 ) $ 11,710 Reserve rights 6,234 (1,857 ) 4,377 6,234 (1,625 ) 4,609 Trade names 1,000 (833 ) 167 1,000 (758 ) 242 Other 409 (179 ) 230 409 (137 ) 272 Total intangible assets $ 26,711 $ (7,819 ) $ 18,892 $ 23,531 $ (6,698 ) $ 16,833 Amortization expense totaled $0.5 million and $1.1 million for the three and nine months ended September 29, 2018 , respectively, and $0.3 million and $1.0 million for the three and nine months ended September 30, 2017 , respectively. The estimated amortization expense for the intangible assets for each of the five years subsequent to September 29, 2018 is as follows: 2018 (three months) $ 412 2019 1,588 2020 1,511 2021 1,475 2022 1,482 2023 1,350 Thereafter 11,074 Total $ 18,892 In September 2018, the Company sold a non-core business in the West segment, resulting in cash proceeds of $21.6 million , and a total gain on the disposition of the business of $12.1 million .
Summit Materials, LLC
Business Acquisition [Line Items]
Summary of Acquisitions by Region	The following table summarizes the Company’s acquisitions by region and period: Nine months ended Year ended September 29, December 30, 2018 2017 West 4 6 East (1) 6 8 _______________________________________________________________________ (1) In addition, the Company acquired certain assets of a small ready-mix concrete operation in the second quarter of 2018.
Summary of Assets Acquired and Liabilities Assumed	The following table summarizes aggregated information regarding the fair values of the assets acquired and liabilities assumed as of the respective acquisition dates: Nine months ended Year ended September 29, December 30, 2018 2017 Financial assets $ 14,275 $ 31,615 Inventories 19,607 8,300 Property, plant and equipment 94,576 160,975 Intangible assets 3,179 161 Other assets 1,264 4,200 Financial liabilities (11,914 ) (15,501 ) Other long-term liabilities (8,255 ) (17,610 ) Net assets acquired 112,732 172,140 Goodwill 106,504 247,536 Purchase price 219,236 419,676 Acquisition-related liabilities (8,342 ) (43,452 ) Other — (1,294 ) Net cash paid for acquisitions $ 210,894 $ 374,930
Goodwill by Reportable Segment and in Total	Changes in the carrying amount of goodwill, by reportable segment, from December 30, 2017 to September 29, 2018 are summarized as follows: West East Cement Total Balance, December 30, 2017 $ 527,290 $ 305,374 $ 204,656 $ 1,037,320 Acquisitions (1) 55,013 57,950 — 112,963 Foreign currency translation adjustments (1,695 ) — — (1,695 ) Balance, September 29, 2018 $ 580,608 $ 363,324 $ 204,656 $ 1,148,588 _______________________________________________________________________ (1) Reflects goodwill from 2018 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: September 29, 2018 December 30, 2017 Gross Carrying Amount Accumulated Amortization Net Carrying Amount Gross Carrying Amount Accumulated Amortization Net Carrying Amount Leases $ 19,068 $ (4,950 ) $ 14,118 $ 15,888 $ (4,178 ) $ 11,710 Reserve rights 6,234 (1,857 ) 4,377 6,234 (1,625 ) 4,609 Trade names 1,000 (833 ) 167 1,000 (758 ) 242 Other 409 (179 ) 230 409 (137 ) 272 Total intangible assets $ 26,711 $ (7,819 ) $ 18,892 $ 23,531 $ (6,698 ) $ 16,833
Estimated Amortization Expense for Intangible Assets	The estimated amortization expense for the intangible assets for each of the five years subsequent to September 29, 2018 is as follows: 2018 (three months) $ 412 2019 1,588 2020 1,511 2021 1,475 2022 1,482 2023 1,350 Thereafter 11,074 Total $ 18,892
Acquisitions and Dispositions	ACQUISITIONS AND DISPOSITIONS Since its formation, the Company has completed numerous acquisitions, 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. The following table summarizes the Company’s acquisitions by region and period: Nine months ended Year ended September 29, December 30, 2018 2017 West 4 6 East (1) 6 8 _______________________________________________________________________ (1) In addition, the Company acquired certain assets of a small ready-mix concrete operation in the second quarter of 2018. The purchase price allocation, primarily the valuation of property, plant and equipment for the 2018 acquisitions, as well as the 2017 acquisitions that occurred after September 30, 2017 , has not yet been finalized due to the recent timing of the acquisitions and status of the valuation of property, plant and equipment. The following table summarizes aggregated information regarding the fair values of the assets acquired and liabilities assumed as of the respective acquisition dates: Nine months ended Year ended September 29, December 30, 2018 2017 Financial assets $ 14,275 $ 31,615 Inventories 19,607 8,300 Property, plant and equipment 94,576 160,975 Intangible assets 3,179 161 Other assets 1,264 4,200 Financial liabilities (11,914 ) (15,501 ) Other long-term liabilities (8,255 ) (17,610 ) Net assets acquired 112,732 172,140 Goodwill 106,504 247,536 Purchase price 219,236 419,676 Acquisition-related liabilities (8,342 ) (43,452 ) Other — (1,294 ) Net cash paid for acquisitions $ 210,894 $ 374,930 Changes in the carrying amount of goodwill, by reportable segment, from December 30, 2017 to September 29, 2018 are summarized as follows: West East Cement Total Balance, December 30, 2017 $ 527,290 $ 305,374 $ 204,656 $ 1,037,320 Acquisitions (1) 55,013 57,950 — 112,963 Foreign currency translation adjustments (1,695 ) — — (1,695 ) Balance, September 29, 2018 $ 580,608 $ 363,324 $ 204,656 $ 1,148,588 _______________________________________________________________________ (1) Reflects goodwill from 2018 acquisitions and working capital adjustments from prior year acquisitions. The Company’s intangible assets are primarily composed of goodwill, lease agreements and reserve rights. The assets related to lease agreements reflect the submarket royalty rates paid under agreements, primarily for extracting aggregates. The values were determined as of the respective acquisition dates by a comparison of market-royalty rates. 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: September 29, 2018 December 30, 2017 Gross Carrying Amount Accumulated Amortization Net Carrying Amount Gross Carrying Amount Accumulated Amortization Net Carrying Amount Leases $ 19,068 $ (4,950 ) $ 14,118 $ 15,888 $ (4,178 ) $ 11,710 Reserve rights 6,234 (1,857 ) 4,377 6,234 (1,625 ) 4,609 Trade names 1,000 (833 ) 167 1,000 (758 ) 242 Other 409 (179 ) 230 409 (137 ) 272 Total intangible assets $ 26,711 $ (7,819 ) $ 18,892 $ 23,531 $ (6,698 ) $ 16,833 Amortization expense totaled $0.5 million and $1.1 million for the three and nine months ended September 29, 2018 , respectively, and $0.3 million and $1.0 million for the three and nine months ended September 30, 2017 , respectively. The estimated amortization expense for the intangible assets for each of the five years subsequent to September 29, 2018 is as follows: 2018 (three months) $ 412 2019 1,588 2020 1,511 2021 1,475 2022 1,482 2023 1,350 Thereafter 11,074 Total $ 18,892 In September 2018, the Company sold a non-core business in the West segment, resulting in cash proceeds of $21.6 million , and a total gain on the disposition of the business of $12.1 million .

Revenue Recognition (Tables)

Revenue Recognition (Tables)	9 Months Ended
	Sep. 29, 2018
Revenue from External Customer [Line Items]
Revenue by Product	Revenue by product for the three and nine months ended September 29, 2018 and September 30, 2017 is as follows: Three months ended Nine months ended September 29, 2018 September 30, 2017 September 29, 2018 September 30, 2017 Revenue by product*: Aggregates $ 109,621 $ 90,594 $ 280,761 $ 236,437 Cement 87,909 94,915 197,439 213,243 Ready-mix concrete 164,866 139,934 447,490 361,824 Asphalt 125,153 115,917 231,666 218,934 Paving and related services 146,477 136,445 288,119 270,449 Other 60,635 56,376 164,497 141,664 Total revenue $ 694,661 $ 634,181 $ 1,609,972 $ 1,442,551 *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 30, 2017 to September 29, 2018 . 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 30, 2017 $ 9,512 $ 15,750 Changes in revenue billed, contract price or cost estimates 37,643 (3,850 ) Acquisitions 483 1,179 Other (9 ) (7 ) Balance - September 29, 2018 $ 47,629 $ 13,072
Summary of Accounts Receivable, Net	Accounts receivable, net consisted of the following as of September 29, 2018 and December 30, 2017 : September 29, 2018 December 30, 2017 Trade accounts receivable $ 220,540 $ 137,696 Construction contract receivables 70,626 49,832 Retention receivables 15,144 14,973 Receivables from related parties 297 468 Accounts receivable 306,607 202,969 Less: Allowance for doubtful accounts (4,937 ) (4,639 ) Accounts receivable, net $ 301,670 $ 198,330
Summit Materials, LLC
Revenue from External Customer [Line Items]
Revenue by Product	Revenue by product for the three and nine months ended September 29, 2018 and September 30, 2017 is as follows: Three months ended Nine months ended September 29, September 30, September 29, September 30, 2018 2017 2018 2017 Revenue by product*: Aggregates $ 109,621 $ 90,594 $ 280,761 $ 236,437 Cement 87,909 94,915 197,439 213,243 Ready-mix concrete 164,866 139,934 447,490 361,824 Asphalt 125,153 115,917 231,666 218,934 Paving and related services 146,477 136,445 288,119 270,449 Other 60,635 56,376 164,497 141,664 Total revenue $ 694,661 $ 634,181 $ 1,609,972 $ 1,442,551 *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 30, 2017 to September 29, 2018 . 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 30, 2017 $ 9,512 $ 15,750 Changes in revenue billed, contract price or cost estimates 37,643 (3,850 ) Acquisitions 483 1,179 Other (9 ) (7 ) Balance - September 29, 2018 $ 47,629 $ 13,072
Summary of Accounts Receivable, Net	September 29, December 30, 2018 2017 Trade accounts receivable $ 220,540 $ 137,696 Construction contract receivables 70,626 49,832 Retention receivables 15,144 14,973 Receivables from related parties 297 468 Accounts receivable 306,607 202,969 Less: Allowance for doubtful accounts (4,937 ) (4,639 ) Accounts receivable, net $ 301,670 $ 198,330

Inventories (Tables)

Inventories (Tables)	9 Months Ended
	Sep. 29, 2018
Inventory [Line Items]
Components of Inventories	Inventories consisted of the following as of September 29, 2018 and December 30, 2017 : September 29, 2018 December 30, 2017 Aggregate stockpiles $ 158,476 $ 126,791 Finished goods 37,917 34,667 Work in process 10,028 7,729 Raw materials 23,340 15,252 Total $ 229,761 $ 184,439
Summit Materials, LLC
Inventory [Line Items]
Components of Inventories	Inventories consisted of the following as of September 29, 2018 and December 30, 2017 : September 29, 2018 December 30, 2017 Aggregate stockpiles $ 158,476 $ 126,791 Finished goods 37,917 34,667 Work in process 10,028 7,729 Raw materials 23,340 15,252 Total $ 229,761 $ 184,439

Accrued Expenses (Tables)

Accrued Expenses (Tables)	9 Months Ended
	Sep. 29, 2018
Schedule Of Accrued Expenses [Line Items]
Components of Accrued Expenses	Accrued expenses consisted of the following as of September 29, 2018 and December 30, 2017 : September 29, 2018 December 30, 2017 Interest $ 23,267 $ 24,095 Payroll and benefits 25,569 33,915 Capital lease obligations 14,955 19,276 Insurance 14,580 11,455 Non-income taxes 14,634 7,236 Professional fees 960 1,717 Other (1) 20,292 18,935 Total $ 114,257 $ 116,629 (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 September 29, 2018 and December 30, 2017 : September 29, 2018 December 30, 2017 Interest $ 23,267 $ 24,095 Payroll and benefits 25,569 33,915 Capital lease obligations 14,955 19,276 Insurance 14,580 11,455 Non-income taxes 14,865 7,467 Professional fees 960 1,717 Other (1) 20,292 18,349 Total $ 114,488 $ 116,274 _______________________________________________________________________ (1) Consists primarily of subcontractor and working capital settlement accruals.

Debt (Tables)

Debt (Tables)	9 Months Ended
	Sep. 29, 2018
Debt Instrument [Line Items]
Schedule of Debt	Debt consisted of the following as of September 29, 2018 and December 30, 2017 : September 29, 2018 December 30, 2017 Term Loan, due 2024: $630.6 million and $635.4 million, net of $1.4 million and $1.6 million discount at September 29, 2018 and December 30, 2017, respectively $ 629,210 $ 633,805 8 1 ⁄ 2 % Senior Notes, due 2022 250,000 250,000 6 1 ⁄ 8 % Senior Notes, due 2023: $650.0 million, net of $1.2 million and $1.4 million discount at September 29, 2018 and December 30, 2017, respectively 648,831 648,650 5 1 ⁄ 8 % Senior Notes, due 2025 300,000 300,000 Total 1,828,041 1,832,455 Current portion of long-term debt 4,765 4,765 Long-term debt $ 1,823,276 $ 1,827,690
Schedule of Contractual Payments of Long-Term Debt	The contractual payments of long-term debt, including current maturities, for the five years subsequent to September 29, 2018 , are as follows: 2018 (three months) $ — 2019 6,354 2020 7,942 2021 6,354 2022 256,354 2023 656,354 Thereafter 897,252 Total 1,830,610 Less: Original issue net discount (2,569 ) Less: Capitalized loan costs (15,086 ) Total debt $ 1,812,955
Summary of Activity for Deferred Financing Fees	The following table presents the activity for the deferred financing fees for the nine months ended September 29, 2018 and September 30, 2017 : Deferred financing fees Balance - December 30, 2017 $ 19,033 Loan origination fees 550 Amortization (3,074 ) Balance - September 29, 2018 $ 16,509 Balance - December 31, 2016 $ 18,290 Loan origination fees 5,317 Amortization (2,945 ) Write off of deferred financing fees (45 ) Balance - September 30, 2017 $ 20,617
Summit Materials, LLC
Debt Instrument [Line Items]
Schedule of Debt	Debt consisted of the following as of September 29, 2018 and December 30, 2017 : September 29, 2018 December 30, 2017 Term Loan, due 2024: $630.6 million and $635.4 million, net of $1.4 million and $1.6 million discount at September 29, 2018 and December 30, 2017, respectively $ 629,210 $ 633,805 8 1/2 % Senior Notes, due 2022 250,000 250,000 6 1/8 % Senior Notes, due 2023: $650.0 million, net of $1.2 million and $1.4 million discount at September 29, 2018 and December 30, 2017, respectively 648,831 648,650 5 1⁄8 % Senior Notes, due 2025 300,000 300,000 Total 1,828,041 1,832,455 Current portion of long-term debt 4,765 4,765 Long-term debt $ 1,823,276 $ 1,827,690
Schedule of Contractual Payments of Long-Term Debt	The contractual payments of long-term debt, including current maturities, for the five years subsequent to September 29, 2018 , are as follows: 2018 (three months) $ — 2019 6,354 2020 7,942 2021 6,354 2022 256,354 2023 656,354 Thereafter 897,252 Total 1,830,610 Less: Original issue net discount (2,569 ) Less: Capitalized loan costs (15,086 ) Total debt $ 1,812,955
Summary of Activity for Deferred Financing Fees	The following table presents the activity for the deferred financing fees for the nine months ended September 29, 2018 and September 30, 2017 : Deferred financing fees Balance - December 30, 2017 $ 19,033 Loan origination fees 550 Amortization (3,074 ) Balance - September 29, 2018 $ 16,509 Balance - December 31, 2016 $ 18,290 Loan origination fees 5,317 Amortization (2,945 ) Write off of deferred financing fees (45 ) Balance - September 30, 2017 $ 20,617

Earnings Per Share (Tables)

Earnings Per Share (Tables)	9 Months Ended
	Sep. 29, 2018
Earnings Per Share [Abstract]
Schedule of Basic Earnings Per Share	The following table shows the calculation of basic earnings per share: Three months ended Nine months ended September 29, 2018 September 30, 2017 September 29, 2018 September 30, 2017 Net income attributable to Summit Inc. $ 71,289 $ 81,264 $ 53,069 $ 78,820 Weighted average shares of Class A stock outstanding 111,641,344 109,545,111 111,288,211 108,219,132 Basic income per share $ 0.64 $ 0.74 $ 0.48 $ 0.73 Diluted net income attributable to Summit Inc. $ 71,289 $ 81,264 $ 53,069 $ 78,820 Weighted average shares of Class A stock outstanding 111,641,344 109,545,111 111,288,211 108,219,132 Add: stock options 204,085 926,613 574,739 184,875 Add: warrants 18,631 39,555 34,134 42,094 Add: restricted stock units 4,515 220,531 402,950 285,088 Add: performance stock units 71,492 92,658 172,690 117,491 Weighted average dilutive shares outstanding 111,940,067 110,824,468 112,472,724 108,848,680 Diluted earnings per share $ 0.64 $ 0.73 $ 0.47 $ 0.72
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 Nine months ended September 29, 2018 September 30, 2017 September 29, 2018 September 30, 2017 Antidilutive shares: LP Units 3,448,343 4,039,020 3,538,385 4,560,976

Stockholders' Equity_Members'_2

Stockholders' Equity/Members' Interest (Tables)	9 Months Ended
	Sep. 29, 2018
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 30, 2017 110,350,594 3,689,620 114,040,214 96.8 % Exchanges during period 254,102 (254,102 ) — Other equity transactions 1,049,856 — 1,049,856 Balance - September 29, 2018 111,654,552 3,435,518 115,090,070 97.0 % Balance - December 31, 2016 97,554,278 5,151,297 102,705,575 95.0 % January 2017 public offering 10,000,000 — 10,000,000 Exchanges during period 1,255,266 (1,255,266 ) — Other equity transactions 1,177,200 — 1,177,200 Balance - September 30, 2017 109,986,744 3,896,031 113,882,775 96.6 %
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 30, 2017 $ 2,364 $ 4,637 $ 385 $ 7,386 Foreign currency translation adjustment, net of tax — (2,295 ) — (2,295 ) Income on cash flow hedges, net of tax — — 1,043 1,043 Balance - September 29, 2018 $ 2,364 $ 2,342 $ 1,428 $ 6,134 Balance - December 31, 2016 $ 1,450 $ (3,106 ) $ (593 ) $ (2,249 ) Postretirement liability adjustment 397 — — 397 Foreign currency translation adjustment — 8,172 — 8,172 Income on cash flow hedges — — 368 368 Balance - September 30, 2017 $ 1,847 $ 5,066 $ (225 ) $ 6,688
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 30, 2017 $ (6,053 ) $ (10,022 ) $ (1,060 ) $ (17,135 ) Foreign currency translation adjustment — (3,179 ) — (3,179 ) Income on cash flow hedges — — 1,443 1,443 Balance - September 29, 2018 $ (6,053 ) $ (13,201 ) $ 383 $ (18,871 ) Balance - December 31, 2016 $ (7,181 ) $ (17,790 ) $ (2,473 ) $ (27,444 ) Postretirement liability adjustment 413 — — 413 Foreign currency translation adjustment — 8,498 — 8,498 Income on cash flow hedges — — 384 384 Balance - September 30, 2017 $ (6,768 ) $ (9,292 ) $ (2,089 ) $ (18,149 )

Supplemental Cash Flow Inform_2

Supplemental Cash Flow Information (Tables)	9 Months Ended
	Sep. 29, 2018
Schedule Of Cash Flow Supplemental [Line Items]
Schedule of Supplemental Cash Flow Information	Supplemental cash flow information is as follows: Nine months ended September 29, 2018 September 30, 2017 Cash payments: Interest $ 79,367 $ 71,117 Income taxes 3,362 1,841 Non cash financing activities: Exchange of LP Units to shares of Class A common stock 7,499 34,831
Summit Materials, LLC
Schedule Of Cash Flow Supplemental [Line Items]
Schedule of Supplemental Cash Flow Information	Supplemental cash flow information is as follows: Nine months ended September 29, 2018 September 30, 2017 Cash payments: Interest $ 79,367 $ 71,117 Income taxes 3,362 1,841

Fair Value (Tables)

Fair Value (Tables)	9 Months Ended
	Sep. 29, 2018
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 September 29, 2018 and December 30, 2017 was: September 29, 2018 December 30, 2017 Current portion of acquisition-related liabilities and Accrued expenses: Contingent consideration $ 3,011 $ 594 Cash flow hedges — 488 Acquisition-related liabilities and Other noncurrent liabilities Contingent consideration $ 3,774 $ 34,301 Cash flow hedges — 492
Schedule of Carrying Value and Fair Value of Financial Instruments	The carrying value and fair value of these financial instruments as of September 29, 2018 and December 30, 2017 was: September 29, 2018 December 30, 2017 Fair Value Carrying Value Fair Value Carrying Value Level 2 Long-term debt(1) $ 1,837,273 $ 1,828,041 $ 1,893,239 $ 1,832,455 Level 3 Current portion of deferred consideration and noncompete obligations(2) 11,137 11,137 13,493 13,493 Long term portion of deferred consideration and noncompete obligations(3) 25,355 25,355 23,834 23,834 (1) $4.8 million was included in current portion of debt as of September 29, 2018 and December 30, 2017 . (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 September 29, 2018 and December 30, 2017 was: September 29, 2018 December 30, 2017 Current portion of acquisition-related liabilities and Accrued expenses: Contingent consideration $ 3,011 $ 594 Cash flow hedges — 488 Acquisition-related liabilities and Other noncurrent liabilities Contingent consideration $ 3,774 $ 34,301 Cash flow hedges — 492
Schedule of Carrying Value and Fair Value of Financial Instruments	The carrying value and fair value of these financial instruments as of September 29, 2018 and December 30, 2017 was: September 29, 2018 December 30, 2017 Fair Value Carrying Value Fair Value Carrying Value Level 2 Long-term debt(1) $ 1,837,273 $ 1,828,041 $ 1,893,239 $ 1,832,455 Level 3 Current portion of deferred consideration and noncompete obligations(2) 8,637 8,637 10,993 10,993 Long term portion of deferred consideration and noncompete obligations(3) 21,411 21,411 17,938 17,938 (1) $4.8 million was included in current portion of debt as of September 29, 2018 and December 30, 2017 . (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)	9 Months Ended
	Sep. 29, 2018
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 September 29, 2018 and December 30, 2017 and for the three and nine months ended September 29, 2018 and September 30, 2017 : Three months ended Nine months ended September 29, 2018 September 30, 2017 September 29, 2018 September 30, 2017 Revenue*: West $ 367,912 $ 327,917 $ 871,338 $ 746,991 East 232,777 204,990 525,270 466,222 Cement 93,972 101,274 213,364 229,338 Total revenue $ 694,661 $ 634,181 $ 1,609,972 $ 1,442,551 *Intercompany sales are immaterial and the presentation above only reflects sales to external customers. Three months ended Nine months ended September 29, 2018 September 30, 2017 September 29, 2018 September 30, 2017 Income (loss) from operations before taxes $ 94,757 $ (414,046 ) $ 71,206 $ (415,809 ) Interest expense 28,889 28,921 86,616 79,876 Depreciation, depletion and amortization 53,494 48,483 149,439 132,374 Accretion 480 486 1,224 1,382 Loss on debt financings — — 149 190 Tax receivable agreement expense — 501,752 — 503,277 Gain on sale of business (12,108 ) — (12,108 ) — Transaction costs 1,260 2,581 3,817 6,474 Non-cash compensation 5,643 4,724 19,833 14,148 Other (409 ) (200 ) (7,316 ) (346 ) Total Adjusted EBITDA $ 172,006 $ 172,701 $ 312,860 $ 321,566 Total Adjusted EBITDA by Segment: West $ 73,916 $ 76,637 $ 151,316 $ 152,856 East 58,305 56,397 100,497 99,511 Cement 44,299 46,860 82,626 93,328 Corporate and other (4,514 ) (7,193 ) (21,579 ) (24,129 ) Total Adjusted EBITDA $ 172,006 $ 172,701 $ 312,860 $ 321,566 Nine months ended September 29, 2018 September 30, 2017 Purchases of property, plant and equipment West $ 104,217 $ 64,257 East 51,968 52,920 Cement 21,621 25,306 Total reportable segments 177,806 142,483 Corporate and other 5,946 4,995 Total purchases of property, plant and equipment $ 183,752 $ 147,478 Three months ended Nine months ended September 29, 2018 September 30, 2017 September 29, 2018 September 30, 2017 Depreciation, depletion, amortization and accretion: West $ 23,289 $ 18,907 $ 68,029 $ 51,989 East 19,429 17,628 54,982 49,939 Cement 10,682 11,815 25,733 29,888 Total reportable segments 53,400 48,350 148,744 131,816 Corporate and other 574 619 1,919 1,940 Total depreciation, depletion, amortization and accretion $ 53,974 $ 48,969 $ 150,663 $ 133,756 September 29, 2018 December 30, 2017 Total assets: West $ 1,422,966 $ 1,225,463 East 1,229,567 1,035,609 Cement 899,077 870,652 Total reportable segments 3,551,610 3,131,724 Corporate and other 344,724 655,609 Total $ 3,896,334 $ 3,787,333
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 September 29, 2018 and December 30, 2017 and for the three and nine months ended September 29, 2018 and September 30, 2017 : Three months ended Nine months ended September 29, September 30, September 29, September 30, 2018 2017 2018 2017 Revenue*: West $ 367,912 $ 327,917 $ 871,338 $ 746,991 East 232,777 204,990 525,270 466,222 Cement 93,972 101,274 213,364 229,338 Total revenue $ 694,661 $ 634,181 $ 1,609,972 $ 1,442,551 *Intercompany sales are immaterial and the presentation above only reflects sales to external customers. Three months ended Nine months ended September 29, September 30, September 29, September 30, 2018 2017 2018 2017 Income from operations before taxes $ 94,926 $ 87,919 $ 71,756 $ 88,149 Interest expense 28,720 28,708 86,066 79,195 Depreciation, depletion and amortization 53,494 48,483 149,439 132,374 Accretion 480 486 1,224 1,382 Loss on debt financings — — 149 190 Gain on sale of business (12,108 ) — (12,108 ) — Transaction costs 1,260 2,581 3,817 6,474 Non-cash compensation 5,643 4,724 19,833 14,148 Other (409 ) (200 ) (7,316 ) (346 ) Total Adjusted EBITDA $ 172,006 $ 172,701 $ 312,860 $ 321,566 Total Adjusted EBITDA by Segment: West $ 73,916 $ 76,637 $ 151,316 $ 152,856 East 58,305 56,397 100,497 99,511 Cement 44,299 46,860 82,626 93,328 Corporate and other (4,514 ) (7,193 ) (21,579 ) (24,129 ) Total Adjusted EBITDA $ 172,006 $ 172,701 $ 312,860 $ 321,566 Nine months ended September 29, 2018 September 30, 2017 Purchases of property, plant and equipment West $ 104,217 $ 64,257 East 51,968 52,920 Cement 21,621 25,306 Total reportable segments 177,806 142,483 Corporate and other 5,946 4,995 Total purchases of property, plant and equipment $ 183,752 $ 147,478 Three months ended Nine months ended September 29, September 30, September 29, September 30, 2018 2017 2018 2017 Depreciation, depletion, amortization and accretion: West $ 23,289 $ 18,907 $ 68,029 $ 51,989 East 19,429 17,628 54,982 49,939 Cement 10,682 11,815 25,733 29,888 Total reportable segments 53,400 48,350 148,744 131,816 Corporate and other 574 619 1,919 1,940 Total depreciation, depletion, amortization and accretion $ 53,974 $ 48,969 $ 150,663 $ 133,756 September 29, 2018 December 30, 2017 Total assets: West $ 1,422,966 $ 1,225,463 East 1,229,567 1,035,609 Cement 899,077 870,652 Total reportable segments 3,551,610 3,131,724 Corporate and other 78,192 372,517 Total $ 3,629,802 $ 3,504,241

Guarantor and Non-Guarantor F_2

Guarantor and Non-Guarantor Financial Information (Tables) - Summit Materials, LLC	9 Months Ended
	Sep. 29, 2018
Condensed Consolidating Balance Sheets	Condensed Consolidating Balance Sheets September 29, 2018 100% Owned Non- Issuers Guarantors Guarantors Eliminations Consolidated Assets Current assets: Cash and cash equivalents $ 75,529 $ 1,946 $ 3,707 $ (16,252 ) $ 64,930 Accounts receivable, net 289 279,071 22,489 (179 ) 301,670 Intercompany receivables 523,663 509,313 — (1,032,976 ) — Cost and estimated earnings in excess of billings — 45,732 1,897 — 47,629 Inventories — 227,047 2,714 — 229,761 Other current assets 1,758 12,986 946 — 15,690 Total current assets 601,239 1,076,095 31,753 (1,049,407 ) 659,680 Property, plant and equipment, net 12,556 1,678,923 60,331 — 1,751,810 Goodwill — 1,089,169 59,419 — 1,148,588 Intangible assets, net — 18,892 — — 18,892 Other assets 3,219,616 160,131 1,449 (3,330,364 ) 50,832 Total assets $ 3,833,411 $ 4,023,210 $ 152,952 $ (4,379,771 ) $ 3,629,802 Liabilities and Member’s Interest Current liabilities: Current portion of debt $ 4,765 $ — $ — $ — $ 4,765 Current portion of acquisition-related liabilities — 11,648 — — 11,648 Accounts payable 4,580 121,519 15,560 (179 ) 141,480 Accrued expenses 42,095 85,922 2,723 (16,252 ) 114,488 Intercompany payables 580,768 438,378 13,830 (1,032,976 ) — Billings in excess of costs and estimated earnings — 12,417 655 — 13,072 Total current liabilities 632,208 669,884 32,768 (1,049,407 ) 285,453 Long-term debt 1,808,190 — — — 1,808,190 Acquisition-related liabilities — 25,185 — — 25,185 Other noncurrent liabilities 3,756 213,054 76,225 (171,318 ) 121,717 Total liabilities 2,444,154 908,123 108,993 (1,220,725 ) 2,240,545 Total member's interest 1,389,257 3,115,087 43,959 (3,159,046 ) 1,389,257 Total liabilities and member’s interest $ 3,833,411 $ 4,023,210 $ 152,952 $ (4,379,771 ) $ 3,629,802 Condensed Consolidating Balance Sheets December 30, 2017 100% Owned Non- Issuers Guarantors Guarantors Eliminations Consolidated Assets Current assets: Cash and cash equivalents $ 370,741 $ 10,254 $ 14,933 $ (12,372 ) $ 383,556 Accounts receivable, net — 183,139 15,191 — 198,330 Intercompany receivables 573,301 484,747 — (1,058,048 ) — Cost and estimated earnings in excess of billings — 9,264 248 — 9,512 Inventories — 180,283 4,156 — 184,439 Other current assets 1,167 6,354 243 — 7,764 Total current assets 945,209 874,041 34,771 (1,070,420 ) 783,601 Property, plant and equipment, net 9,259 1,569,118 37,047 — 1,615,424 Goodwill — 976,206 61,114 — 1,037,320 Intangible assets, net — 16,833 — — 16,833 Other assets 2,890,674 162,711 1,271 (3,003,593 ) 51,063 Total assets $ 3,845,142 $ 3,598,909 $ 134,203 $ (4,074,013 ) $ 3,504,241 Liabilities and Member’s Interest Current liabilities: Current portion of debt $ 4,765 $ — $ — $ — $ 4,765 Current portion of acquisition-related liabilities — 11,587 — — 11,587 Accounts payable 3,976 89,912 6,749 — 100,637 Accrued expenses 47,047 79,372 2,227 (12,372 ) 116,274 Intercompany payables 684,057 369,918 4,073 (1,058,048 ) — Billings in excess of costs and estimated earnings — 15,349 401 — 15,750 Total current liabilities 739,845 566,138 13,450 (1,070,420 ) 249,013 Long-term debt 1,810,833 — — — 1,810,833 Acquisition-related liabilities — 52,239 — — 52,239 Other noncurrent liabilities 2,870 193,801 75,209 (171,318 ) 100,562 Total liabilities 2,553,548 812,178 88,659 (1,241,738 ) 2,212,647 Total member's interest 1,291,594 2,786,731 45,544 (2,832,275 ) 1,291,594 Total liabilities and member’s interest $ 3,845,142 $ 3,598,909 $ 134,203 $ (4,074,013 ) $ 3,504,241
Condensed Consolidating Statements of Operations and Comprehensive Loss	Condensed Consolidating Statements of Operations For the three months ended September 29, 2018 100% Owned Non- Issuers Guarantors Guarantors Eliminations Consolidated Revenue $ — $ 668,145 $ 28,064 $ (1,548 ) $ 694,661 Cost of revenue (excluding items shown separately below) — 452,394 20,957 (1,548 ) 471,803 General and administrative expenses 10,951 46,910 2,856 — 60,717 Depreciation, depletion, amortization and accretion 574 52,213 1,187 — 53,974 Operating (loss) income (11,525 ) 116,628 3,064 — 108,167 Other income, net (132,382 ) (3,019 ) (236 ) 132,266 (3,371 ) Interest expense (income) 29,396 (1,882 ) 1,206 — 28,720 Gain on sale of business — (12,108 ) — — (12,108 ) Income from operations before taxes 91,461 133,637 2,094 (132,266 ) 94,926 Income tax expense 1,034 2,898 567 — 4,499 Net income attributable to member of Summit Materials, LLC $ 90,427 $ 130,739 $ 1,527 $ (132,266 ) $ 90,427 Comprehensive income (loss) attributable to member of Summit Materials, LLC $ 92,484 $ 130,652 $ (443 ) $ (130,209 ) $ 92,484 Condensed Consolidating Statements of Operations For the nine months ended September 29, 2018 100% Owned Non- Issuers Guarantors Guarantors Eliminations Consolidated Revenue $ — $ 1,548,960 $ 65,597 $ (4,585 ) $ 1,609,972 Cost of revenue (excluding items shown separately below) — 1,087,150 48,031 (4,585 ) 1,130,596 General and administrative expenses 45,175 141,372 8,245 — 194,792 Depreciation, depletion, amortization and accretion 1,919 145,135 3,609 — 150,663 Operating (loss) income (47,094 ) 175,303 5,712 — 133,921 Other (income) loss, net (204,677 ) (10,563 ) (87 ) 203,534 (11,793 ) Interest expense (income) 87,924 (5,447 ) 3,589 — 86,066 Gain on sale of business — (12,108 ) — — (12,108 ) Income from operations before taxes 69,659 203,421 2,210 (203,534 ) 71,756 Income tax expense 1,226 1,481 616 — 3,323 Net income attributable to member of Summit Materials, LLC $ 68,433 $ 201,940 $ 1,594 $ (203,534 ) $ 68,433 Comprehensive income attributable to member of Summit Materials, LLC $ 66,697 $ 200,497 $ 4,773 $ (205,270 ) $ 66,697 Condensed Consolidating Statements of Operations For the three months ended September 30, 2017 100% Owned Non- Issuers Guarantors Guarantors Eliminations Consolidated Revenue $ — $ 606,046 $ 29,608 $ (1,473 ) $ 634,181 Cost of revenue (excluding items shown separately below) — 389,716 21,302 (1,473 ) 409,545 General and administrative expenses 15,011 44,373 2,372 — 61,756 Depreciation, depletion, amortization and accretion 619 47,032 1,318 — 48,969 Operating (loss) income (15,630 ) 124,925 4,616 — 113,911 Other income, net (126,386 ) (1,569 ) (245 ) 125,484 (2,716 ) Interest expense (income) 28,182 (670 ) 1,196 — 28,708 Income from operations before taxes 82,574 127,164 3,665 (125,484 ) 87,919 Income tax expense — 4,397 889 — 5,286 Net income 82,574 122,767 2,776 (125,484 ) 82,633 Net income attributable to noncontrolling interest — — — 59 59 Net income attributable to member of Summit Materials, LLC $ 82,574 $ 122,767 $ 2,776 $ (125,543 ) $ 82,574 Comprehensive income (loss) attributable to member of Summit Materials, LLC $ 87,160 $ 122,555 $ (1,598 ) $ (120,957 ) $ 87,160 Condensed Consolidating Statements of Operations For the nine months ended September 30, 2017 100% Owned Non- Issuers Guarantors Guarantors Eliminations Consolidated Revenue $ — $ 1,384,956 $ 62,230 $ (4,635 ) $ 1,442,551 Cost of revenue (excluding items shown separately below) — 922,024 45,632 (4,635 ) 963,021 General and administrative expenses 44,718 131,770 5,715 — 182,203 Depreciation, depletion, amortization and accretion 1,940 128,851 2,965 — 133,756 Operating (loss) income (46,658 ) 202,311 7,918 — 163,571 Other income, net (204,877 ) (1,561 ) (500 ) 203,165 (3,773 ) Interest expense (income) 76,586 (533 ) 3,142 — 79,195 Income from operations before taxes 81,633 204,405 5,276 (203,165 ) 88,149 Income tax expense — 5,119 1,424 — 6,543 Net income 81,633 199,286 3,852 (203,165 ) 81,606 Net loss attributable to noncontrolling interest — — — (27 ) (27 ) Net income attributable to member of Summit Materials, LLC $ 81,633 $ 199,286 $ 3,852 $ (203,138 ) $ 81,633 Comprehensive income (loss) attributable to member of Summit Materials, LLC $ 90,928 $ 198,489 $ (4,646 ) $ (193,843 ) $ 90,928
Condensed Consolidating Statements of Cash Flows	Condensed Consolidating Statements of Cash Flows For the nine months ended September 29, 2018 100% Owned Non- Issuers Guarantors Guarantors Eliminations Consolidated Net cash (used in) provided by operating activities $ (107,736 ) $ 173,597 $ 4,696 $ — $ 70,557 Cash flow from investing activities: Acquisitions, net of cash acquired — (210,894 ) — — (210,894 ) Purchase of property, plant and equipment (5,946 ) (156,016 ) (21,790 ) — (183,752 ) Proceeds from the sale of property, plant, and equipment — 18,257 169 — 18,426 Proceeds from the sale of a business — 21,564 — — 21,564 Other — 2,660 — — 2,660 Net cash used for investing activities (5,946 ) (324,429 ) (21,621 ) — (351,996 ) Cash flow from financing activities: Proceeds from investment by member (112,386 ) 128,001 — — 15,615 Net proceeds from debt issuance 64,500 — — — 64,500 Loans received from and payments made on loans from other Summit Companies (60,387 ) 58,052 6,215 (3,880 ) — Payments on long-term debt (69,265 ) (9,701 ) (61 ) — (79,027 ) Payments on acquisition-related liabilities — (32,821 ) — — (32,821 ) Debt issuance costs (550 ) — — — (550 ) Distributions from partnership (2,569 ) — — — (2,569 ) Other (873 ) (1,007 ) (33 ) — (1,913 ) Net cash (used in) provided by financing activities (181,530 ) 142,524 6,121 (3,880 ) (36,765 ) Impact of cash on foreign currency — — (422 ) — (422 ) Net decrease in cash (295,212 ) (8,308 ) (11,226 ) (3,880 ) (318,626 ) Cash — Beginning of period 370,741 10,254 14,933 (12,372 ) 383,556 Cash — End of period $ 75,529 $ 1,946 $ 3,707 $ (16,252 ) $ 64,930 Condensed Consolidating Statements of Cash Flows For the nine months ended September 30, 2017 100% Owned Non- Issuers Guarantors Guarantors Eliminations Consolidated Net cash (used in) provided by operating activities $ (92,840 ) $ 198,890 $ 26,845 $ — $ 132,895 Cash flow from investing activities: Acquisitions, net of cash acquired (24,538 ) (321,340 ) (25,601 ) — (371,479 ) Purchase of property, plant and equipment (4,994 ) (137,505 ) (4,979 ) — (147,478 ) Proceeds from the sale of property, plant, and equipment — 13,231 59 — 13,290 Other — 182 — — 182 Net cash used for investing activities (29,532 ) (445,432 ) (30,521 ) — (505,485 ) Cash flow from financing activities: Proceeds from investment by member (3,409 ) 249,359 10,717 — 256,667 Capital issuance costs (627 ) — — — (627 ) Net proceeds from debt issuance 302,000 — — — 302,000 Loans received from and payments made on loans from other Summit Companies (10,787 ) 20,975 (6,282 ) (3,906 ) — Payments on long-term debt (6,874 ) (6,009 ) (4 ) — (12,887 ) Payments on acquisition-related liabilities — (20,116 ) — — (20,116 ) Financing costs (5,317 ) — — — (5,317 ) Distributions from partnership (2,609 ) — — — (2,609 ) Other (536 ) (288 ) (21 ) — (845 ) Net cash provided by financing activities 271,841 243,921 4,410 (3,906 ) 516,266 Impact of cash on foreign currency — — 734 — 734 Net increase (decrease) in cash 149,469 (2,621 ) 1,468 (3,906 ) 144,410 Cash — Beginning of period 133,862 4,820 14,656 (10,666 ) 142,672 Cash — End of period $ 283,331 $ 2,199 $ 16,124 $ (14,572 ) $ 287,082

Summary of Organization and S_3

Summary of Organization and Significant Accounting Policies - General Information and Equity Offerings (Details) $ in Millions	Jan. 10, 2017USD ($)acquistiion	Oct. 31, 2017	Sep. 29, 2018segmentplant
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 Holdings LP
Summary Of Significant Accounting Policies And Recent Accounting Pronouncements [Line Items]
Voting power (as a percent)			100.00%
Acquisition payments | $	$ 110
Number of business acquisitions | acquistiion	2
Summit Materials, LLC
Summary Of Significant Accounting Policies And Recent Accounting Pronouncements [Line Items]
Number of operating segments			3
Summit Materials, LLC | Ohio Valley Asphalt
Summary Of Significant Accounting Policies And Recent Accounting Pronouncements [Line Items]
Minority interest purchased (as a percent)		20.00%

Summary of Organization and S_4

Summary of Organization and Significant Accounting Policies - Business and Credit Concentration (Details)	9 Months Ended
	Sep. 29, 2018state
Business and Credit Concentrations
Number of states in which the entity operates	23
Summit Materials, LLC
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 Summary of Organization and Significant Accounting Policies - Revenue Recognition (Details)	9 Months Ended
	Sep. 29, 2018
Minimum | Product
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Timing of collection on product and service revenue	30 days
Minimum | Product | Summit Materials, LLC
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Timing of collection on product and service revenue	30 days
Maximum | Product
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Timing of collection on product and service revenue	60 days
Maximum | Product | Summit Materials, LLC
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Timing of collection on product and service revenue	60 days
Maximum | Service
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Timing of collection on product and service revenue	90 days
Maximum | Service | Summit Materials, LLC
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Timing of collection on product and service revenue	90 days

Summary of Organization and S_6

Summary of Organization and Significant Accounting Policies - Reclassifications (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2017USD ($)
Other current assets
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Reclassification adjustment	$ 17
Deferred tax assets, net
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Reclassification adjustment	498,800
Deferred income tax benefit
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Reclassification adjustment	$ (4,800)

Acquisitions and Dispositions -

Acquisitions and Dispositions - Completed Acquisitions Information (Details) - acquistiion	9 Months Ended	12 Months Ended
	Sep. 29, 2018	Dec. 30, 2017
West
Business Acquisition [Line Items]
Number of business acquisitions	4	6
East
Business Acquisition [Line Items]
Number of business acquisitions	6	8
Summit Materials, LLC | West
Business Acquisition [Line Items]
Number of business acquisitions	4	6
Summit Materials, LLC | East
Business Acquisition [Line Items]
Number of business acquisitions	6	8

Acquisitions and Dispositions_2

Acquisitions and Dispositions - Summary of Assets Acquired and Liabilities Assumed (Detail) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 29, 2018	Dec. 30, 2017
Business Acquisition [Line Items]
Goodwill	$ 1,147,588	$ 1,036,320
Cement
Business Acquisition [Line Items]
Goodwill	204,656	204,656
2017 Acquisitions
Business Acquisition [Line Items]
Financial assets		31,615
Inventories		8,300
Property, plant and equipment		160,975
Intangible assets		161
Other assets		4,200
Financial liabilities		(15,501)
Other long-term liabilities		(17,610)
Net assets acquired		172,140
Goodwill		247,536
Purchase price		419,676
Acquisition-related liabilities		(43,452)
Other		(1,294)
Net cash paid for acquisitions		374,930
2018 Acquisitions
Business Acquisition [Line Items]
Financial assets	14,275
Inventories	19,607
Property, plant and equipment	94,576
Intangible assets	3,179
Other assets	1,264
Financial liabilities	(11,914)
Other long-term liabilities	(8,255)
Net assets acquired	112,732
Goodwill	106,504
Purchase price	219,236
Acquisition-related liabilities	(8,342)
Other	0
Net cash paid for acquisitions	210,894
Summit Materials, LLC
Business Acquisition [Line Items]
Goodwill	1,148,588	1,037,320
Summit Materials, LLC | Cement
Business Acquisition [Line Items]
Goodwill	204,656	204,656
Summit Materials, LLC | 2017 Acquisitions
Business Acquisition [Line Items]
Financial assets		31,615
Inventories		8,300
Property, plant and equipment		160,975
Intangible assets		161
Other assets		4,200
Financial liabilities		(15,501)
Other long-term liabilities		(17,610)
Net assets acquired		172,140
Goodwill		247,536
Purchase price		419,676
Acquisition-related liabilities		(43,452)
Other		(1,294)
Net cash paid for acquisitions		$ 374,930
Summit Materials, LLC | 2018 Acquisitions
Business Acquisition [Line Items]
Financial assets	14,275
Inventories	19,607
Property, plant and equipment	94,576
Intangible assets	3,179
Other assets	1,264
Financial liabilities	(11,914)
Other long-term liabilities	(8,255)
Net assets acquired	112,732
Goodwill	106,504
Purchase price	219,236
Acquisition-related liabilities	(8,342)
Other	0
Net cash paid for acquisitions	$ 210,894

Acquisitions and Dispositions_3

Acquisitions and Dispositions - Summary of Goodwill by Reportable Segments (Details) $ in Thousands	9 Months Ended
	Sep. 29, 2018USD ($)
Goodwill [Roll Forward]
Balance, December 30, 2017	$ 1,036,320
Acquisitions	112,963
Foreign currency translation adjustments	(1,695)
Balance, September 29, 2018	1,147,588
West
Goodwill [Roll Forward]
Balance, December 30, 2017	526,290
Acquisitions	55,013
Foreign currency translation adjustments	(1,695)
Balance, September 29, 2018	579,608
East
Goodwill [Roll Forward]
Balance, December 30, 2017	305,374
Acquisitions	57,950
Foreign currency translation adjustments	0
Balance, September 29, 2018	363,324
Cement
Goodwill [Roll Forward]
Balance, December 30, 2017	204,656
Acquisitions	0
Foreign currency translation adjustments	0
Balance, September 29, 2018	204,656
Summit Materials, LLC
Goodwill [Roll Forward]
Balance, December 30, 2017	1,037,320
Acquisitions	112,963
Foreign currency translation adjustments	(1,695)
Balance, September 29, 2018	1,148,588
Summit Materials, LLC | West
Goodwill [Roll Forward]
Balance, December 30, 2017	527,290
Acquisitions	55,013
Foreign currency translation adjustments	(1,695)
Balance, September 29, 2018	580,608
Summit Materials, LLC | East
Goodwill [Roll Forward]
Balance, December 30, 2017	305,374
Acquisitions	57,950
Foreign currency translation adjustments	0
Balance, September 29, 2018	363,324
Summit Materials, LLC | Cement
Goodwill [Roll Forward]
Balance, December 30, 2017	204,656
Acquisitions	0
Foreign currency translation adjustments	0
Balance, September 29, 2018	$ 204,656

Acquisitions and Dispositions_4

Acquisitions and Dispositions - Intangible Assets By Type (Details) - USD ($) $ in Thousands	Sep. 29, 2018	Dec. 30, 2017
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 26,711	$ 23,531
Accumulated Amortization	(7,819)	(6,698)
Net Carrying Amount	18,892	16,833
Leases
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	19,068	15,888
Accumulated Amortization	(4,950)	(4,178)
Net Carrying Amount	14,118	11,710
Reserve rights
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	6,234	6,234
Accumulated Amortization	(1,857)	(1,625)
Net Carrying Amount	4,377	4,609
Trade names
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	1,000	1,000
Accumulated Amortization	(833)	(758)
Net Carrying Amount	167	242
Other
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	409	409
Accumulated Amortization	(179)	(137)
Net Carrying Amount	230	272
Summit Materials, LLC
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	26,711	23,531
Accumulated Amortization	(7,819)	(6,698)
Net Carrying Amount	18,892	16,833
Summit Materials, LLC | Leases
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	19,068	15,888
Accumulated Amortization	(4,950)	(4,178)
Net Carrying Amount	14,118	11,710
Summit Materials, LLC | Reserve rights
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	6,234	6,234
Accumulated Amortization	(1,857)	(1,625)
Net Carrying Amount	4,377	4,609
Summit Materials, LLC | Trade names
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	1,000	1,000
Accumulated Amortization	(833)	(758)
Net Carrying Amount	167	242
Summit Materials, LLC | Other
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	409	409
Accumulated Amortization	(179)	(137)
Net Carrying Amount	$ 230	$ 272

Acquisitions and Dispositions_5

Acquisitions and Dispositions - Amortization Expense (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 29, 2018	Sep. 30, 2017	Sep. 29, 2018	Sep. 30, 2017	Dec. 30, 2017
Business Acquisition [Line Items]
Amortization expense	$ 500	$ 300	$ 1,100	$ 1,000
Estimated amortization expense
2018 (three months)	412		412
2,019	1,588		1,588
2,020	1,511		1,511
2,021	1,475		1,475
2,022	1,482		1,482
2,023	1,350		1,350
Thereafter	11,074		11,074
Total	18,892		18,892		$ 16,833
Summit Materials, LLC
Business Acquisition [Line Items]
Amortization expense	500	$ 300	1,100	$ 1,000
Estimated amortization expense
2018 (three months)	412		412
2,019	1,588		1,588
2,020	1,511		1,511
2,021	1,475		1,475
2,022	1,482		1,482
2,023	1,350		1,350
Thereafter	11,074		11,074
Total	$ 18,892		$ 18,892		$ 16,833

Acquisitions and Dispositions_6

Acquisitions and Dispositions - Completed Dispositions Information (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 29, 2018	Sep. 30, 2017	Sep. 29, 2018	Sep. 30, 2017
Business Acquisition [Line Items]
Proceeds from sale of business			$ 21,564	$ 0
Gain on sale of business	$ 12,108	$ 0	12,108	0
Summit Materials, LLC
Business Acquisition [Line Items]
Proceeds from sale of business			21,564	0
Gain on sale of business	12,108	$ 0	12,108	$ 0
West
Business Acquisition [Line Items]
Proceeds from sale of business			21,564
Gain on sale of business	$ 12,108
West | Summit Materials, LLC
Business Acquisition [Line Items]
Proceeds from sale of business			21,600
Gain on sale of business			$ 12,100

Revenue Recognition - By Produc

Revenue Recognition - By Product (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 29, 2018	Sep. 30, 2017	Sep. 29, 2018	Sep. 30, 2017
Revenue from External Customer [Line Items]
Total revenue	$ 694,661	$ 634,181	$ 1,609,972	$ 1,442,551
Aggregates
Revenue from External Customer [Line Items]
Total revenue	109,621	90,594	280,761	236,437
Cement
Revenue from External Customer [Line Items]
Total revenue	87,909	94,915	197,439	213,243
Ready-mix concrete
Revenue from External Customer [Line Items]
Total revenue	164,866	139,934	447,490	361,824
Asphalt
Revenue from External Customer [Line Items]
Total revenue	125,153	115,917	231,666	218,934
Paving and related services
Revenue from External Customer [Line Items]
Total revenue	146,477	136,445	288,119	270,449
Other
Revenue from External Customer [Line Items]
Total revenue	60,635	56,376	164,497	141,664
Summit Materials, LLC
Revenue from External Customer [Line Items]
Total revenue	694,661	634,181	1,609,972	1,442,551
Summit Materials, LLC | Aggregates
Revenue from External Customer [Line Items]
Total revenue	109,621	90,594	280,761	236,437
Summit Materials, LLC | Cement
Revenue from External Customer [Line Items]
Total revenue	87,909	94,915	197,439	213,243
Summit Materials, LLC | Ready-mix concrete
Revenue from External Customer [Line Items]
Total revenue	164,866	139,934	447,490	361,824
Summit Materials, LLC | Asphalt
Revenue from External Customer [Line Items]
Total revenue	125,153	115,917	231,666	218,934
Summit Materials, LLC | Paving and related services
Revenue from External Customer [Line Items]
Total revenue	146,477	136,445	288,119	270,449
Summit Materials, LLC | Other
Revenue from External Customer [Line Items]
Total revenue	$ 60,635	$ 56,376	$ 164,497	$ 141,664

Revenue Recognition - Contract

Revenue Recognition - Contract Assets and Liabilities (Details) $ in Thousands	9 Months Ended
	Sep. 29, 2018USD ($)
Change in Contract with Customer, Asset [Abstract]
Beginning balance	$ 9,512
Changes in revenue billed, contract price or cost estimates	37,643
Acquisitions	483
Other	(9)
Ending balance	47,629
Change in Contract with Customer, Liability [Abstract]
Beginning balance	15,750
Changes in revenue billed, contract price or cost estimates	(3,850)
Acquisitions	1,179
Other	(7)
Ending balance	13,072
Summit Materials, LLC
Change in Contract with Customer, Asset [Abstract]
Beginning balance	9,512
Changes in revenue billed, contract price or cost estimates	37,643
Acquisitions	483
Other	(9)
Ending balance	47,629
Change in Contract with Customer, Liability [Abstract]
Beginning balance	15,750
Changes in revenue billed, contract price or cost estimates	(3,850)
Acquisitions	1,179
Other	(7)
Ending balance	$ 13,072

Revenue Recognition - Summary o

Revenue Recognition - Summary of Accounts Receivable, Net (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 29, 2018	Dec. 30, 2017
Accounts, Notes, Loans and Financing Receivable [Line Items]
Trade accounts receivable	$ 220,540	$ 137,696
Construction contract receivables	70,626	49,832
Retention receivables	15,144	14,973
Receivables from related parties	297	468
Accounts receivable	306,607	202,969
Less: Allowance for doubtful accounts	(4,937)	(4,639)
Accounts receivable, net	$ 301,670	198,330
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	$ 220,540	137,696
Construction contract receivables	70,626	49,832
Retention receivables	15,144	14,973
Receivables from related parties	297	468
Accounts receivable	306,607	202,969
Less: Allowance for doubtful accounts	(4,937)	(4,639)
Accounts receivable, net	$ 301,670	$ 198,330
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	Sep. 29, 2018	Dec. 30, 2017
Inventory [Line Items]
Aggregate stockpiles	$ 158,476	$ 126,791
Finished goods	37,917	34,667
Work in process	10,028	7,729
Raw materials	23,340	15,252
Total	229,761	184,439
Summit Materials, LLC
Inventory [Line Items]
Aggregate stockpiles	158,476	126,791
Finished goods	37,917	34,667
Work in process	10,028	7,729
Raw materials	23,340	15,252
Total	$ 229,761	$ 184,439

Accrued Expenses - Components o

Accrued Expenses - Components of Accrued Expenses (Details) - USD ($) $ in Thousands	Sep. 29, 2018	Dec. 30, 2017
Schedule Of Accrued Expenses [Line Items]
Interest	$ 23,267	$ 24,095
Payroll and benefits	25,569	33,915
Capital lease obligations	14,955	19,276
Insurance	14,580	11,455
Non-income taxes	14,634	7,236
Professional fees	960	1,717
Other	20,292	18,935
Total	114,257	116,629
Summit Materials, LLC
Schedule Of Accrued Expenses [Line Items]
Interest	23,267	24,095
Payroll and benefits	25,569	33,915
Capital lease obligations	14,955	19,276
Insurance	14,580	11,455
Non-income taxes	14,865	7,467
Professional fees	960	1,717
Other	20,292	18,349
Total	$ 114,488	$ 116,274

Debt - Schedule of Debt (Detail

Debt - Schedule of Debt (Details) - USD ($) $ in Thousands	Sep. 29, 2018	May 22, 2018	Dec. 30, 2017	Nov. 21, 2017	Jun. 01, 2017	Jan. 19, 2017	Mar. 08, 2016	Jul. 08, 2015
Debt Instrument [Line Items]
Total debt	$ 1,828,041		$ 1,832,455
Current portion of long-term debt	4,765		4,765
Long-term debt	1,823,276		1,827,690
Gross amount	1,830,610
Debt discount	2,569
Term Loan, due 2022
Debt Instrument [Line Items]
Total debt	629,210		633,805
Gross amount	630,600	$ 633,800	635,400	$ 635,400		$ 640,300
Debt discount	$ 1,400		1,600
8 1/2% Senior Notes, due 2022
Debt Instrument [Line Items]
Total debt			250,000
Debt instrument interest rate (as a percent)	8.50%
6 1/8% Senior Notes, due 2023
Debt Instrument [Line Items]
Total debt	$ 648,831		648,650
Gross amount	650,000		650,000
Debt discount	$ 1,200		1,400
Debt instrument interest rate (as a percent)	6.125%
5 1/8% Senior Notes, due 2025
Debt Instrument [Line Items]
Total debt			300,000
Debt instrument interest rate (as a percent)	5.125%
Summit Materials, LLC
Debt Instrument [Line Items]
Total debt	$ 1,828,041		1,832,455
Current portion of long-term debt	4,765		4,765
Long-term debt	1,823,276		1,827,690
Gross amount	1,830,610
Debt discount	2,569
Summit Materials, LLC | Term Loan, due 2022
Debt Instrument [Line Items]
Total debt	629,210		633,805
Gross amount	630,600	$ 633,800	635,400	$ 635,400		$ 640,300
Debt discount	1,400		1,600
Summit Materials, LLC | 8 1/2% Senior Notes, due 2022
Debt Instrument [Line Items]
Total debt	$ 250,000		250,000				$ 250,000
Debt instrument interest rate (as a percent)	8.50%						8.50%
Summit Materials, LLC | 6 1/8% Senior Notes, due 2023
Debt Instrument [Line Items]
Total debt	$ 648,831		648,650
Gross amount	650,000		650,000
Debt discount	$ 1,200		1,400
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%

Debt - Schedule of Contractual

Debt - Schedule of Contractual Payments of Long-Term Debt (Details) $ in Thousands	Sep. 29, 2018USD ($)
Debt Instrument [Line Items]
2018 (three months)	$ 0
2,019	6,354
2,020	7,942
2,021	6,354
2,022	256,354
2,023	656,354
Thereafter	897,252
Total	1,830,610
Less: Original issue net discount	(2,569)
Less: Capitalized loan costs	(15,086)
Total debt	1,812,955
Summit Materials, LLC
Debt Instrument [Line Items]
2018 (three months)	0
2,019	6,354
2,020	7,942
2,021	6,354
2,022	256,354
2,023	656,354
Thereafter	897,252
Total	1,830,610
Less: Original issue net discount	(2,569)
Less: Capitalized loan costs	(15,086)
Total debt	$ 1,812,955

Debt - Senior Notes (Details)

Debt - Senior Notes (Details) - USD ($) $ in Thousands	Jun. 01, 2017	Mar. 08, 2016	Jul. 08, 2015	Sep. 29, 2018	Dec. 30, 2017
Debt Instrument [Line Items]
Long-term debt				$ 1,828,041	$ 1,832,455
5 1/8% Senior Notes, due 2025
Debt Instrument [Line Items]
Long-term debt					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					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				$ 648,831	648,650
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]
Long-term debt	$ 300,000
Senior notes, interest rate (as a percent)	5.125%
Issuers | 8 1/2% Senior Notes, due 2022
Debt Instrument [Line Items]
Long-term debt		$ 250,000
Senior notes, interest rate (as a percent)		8.50%
Percentage of par value of senior notes		100.00%
Proceeds net of related fees and expenses		$ 246,300
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]
Long-term debt				$ 1,828,041	1,832,455
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		$ 250,000		$ 250,000	250,000
Senior notes, interest rate (as a percent)		8.50%		8.50%
Summit Materials, LLC | 6 1/8% Senior Notes, due 2023
Debt Instrument [Line Items]
Long-term debt				$ 648,831	$ 648,650
Senior notes, interest rate (as a percent)			6.125%	6.125%

Debt - Senior Secured Credit Fa

Debt - Senior Secured Credit Facilities (Details) - USD ($)	May 22, 2018	Sep. 29, 2018	Dec. 30, 2017	Nov. 21, 2017	Jan. 19, 2017	Jul. 08, 2015
Debt Instrument [Line Items]
Outstanding principal amount		$ 1,830,610,000
Summit Materials, LLC
Debt Instrument [Line Items]
Outstanding principal amount		1,830,610,000
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]
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 2022
Debt Instrument [Line Items]
Outstanding principal amount	$ 633,800,000	$ 630,600,000	635,400,000	$ 635,400,000	$ 640,300,000
Term Loan, due 2022 | Summit Materials, LLC
Debt Instrument [Line Items]
Debt instrument, face amount						$ 650,000,000
Quarterly principal repayments percentage		0.25%
Outstanding principal amount	$ 633,800,000	$ 630,600,000	635,400,000	$ 635,400,000	$ 640,300,000
Revolving Credit Facility | Summit Materials, LLC
Debt Instrument [Line Items]
Maximum borrowing capacity		235,000,000
Amount outstanding		0	$ 0
Remaining borrowing capacity		219,600,000
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	2.25%
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		$ 15,400,000

Debt - Summary of Activity for

Debt - Summary of Activity for Deferred Financing Fees (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 29, 2018	Sep. 30, 2017
Deferred Finance Costs, Own-share Lending Arrangement, Issuance Costs, Accumulated Amortization [Roll Forward]
Beginning balance	$ 19,033	$ 18,290
Loan origination fees	550	5,317
Amortization	(3,074)	(2,945)
Write off of deferred financing fees		(45)
Ending balance	16,509	20,617
Summit Materials, LLC
Deferred Finance Costs, Own-share Lending Arrangement, Issuance Costs, Accumulated Amortization [Roll Forward]
Beginning balance	19,033	18,290
Loan origination fees	550	5,317
Amortization	(3,074)	(2,945)
Write off of deferred financing fees		(45)
Ending balance	$ 16,509	$ 20,617

Debt - Other (Details)

Debt - Other (Details) - CAD ($)	Jan. 15, 2015	Sep. 29, 2018	Dec. 30, 2017
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 ($)	3 Months Ended		9 Months Ended
	Sep. 29, 2018	Sep. 30, 2017	Sep. 29, 2018	Sep. 30, 2017	Dec. 30, 2017
Income Taxes [Line Items]
Income tax expense (benefit)	$ 20,765,000	$ (498,333,000)	$ 16,249,000	$ (497,076,000)
Decrease in deferred tax liabilities		29,600,000
Decrease in deferred tax asset, valuation allowance				532,000,000
Valuation Allowance
Valuation allowance	1,675,000		1,675,000		$ 1,675,000
Deferred tax asset, Investment in limited partnership	2,200,000		2,200,000
Tax receivable agreement liability	333,152,000	501,800,000	333,152,000	501,800,000	331,340,000
Liabilities recognized for uncertain tax positions	0		0		0
Income tax provision, interest or penalties recognized	0	0	0	0
Tax Receivable Agreement
Valuation Allowance
Tax receivable agreement liability					331,900,000
Tax Receivable Agreement | Accrued expenses.
Valuation Allowance
Tax receivable agreement liability					600,000
Summit Holdings LP
Valuation Allowance
Distributions to LP Unitholders			$ 100,000	100,000
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)	4,499,000	5,286,000	$ 3,323,000	6,543,000
Valuation Allowance
Liabilities recognized for uncertain tax positions	0		0		$ 0
Income tax provision, interest or penalties recognized	$ 0	$ 0	$ 0	$ 0
Common Class A
Valuation Allowance
Number of Summit LP units purchased by Company, newly issued units (in shares)			254,102

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		9 Months Ended
	Sep. 29, 2018	Sep. 30, 2017	Sep. 29, 2018	Sep. 30, 2017
Reconciliation of basic to diluted loss per share
Net income attributable to Summit Inc.	$ 71,289	$ 81,264	$ 53,069	$ 78,820
Diluted net income attributable to Summit Inc.	$ 71,289	$ 81,264	$ 53,069	$ 78,820
LP Units
Reconciliation of basic to diluted loss per share
Anti dilutive shares excluded from calculation of earnings per share (in shares)	3,448,343	4,039,020	3,538,385	4,560,976
Common Class A
Reconciliation of basic to diluted loss per share
Weighted average shares of Class A stock outstanding (in shares)	111,641,344	109,545,111	111,288,211	108,219,132
Basic income (loss) per share (usd per share)	$ 0.64	$ 0.74	$ 0.48	$ 0.73
Add: warrants	18,631	39,555	34,134	42,094
Weighted average dilutive shares outstanding (in shares)	111,940,067	110,824,468	112,472,724	108,848,680
Diluted earnings per share (usd per share)	$ 0.64	$ 0.73	$ 0.47	$ 0.72
Common Class A | Stock options
Reconciliation of basic to diluted loss per share
Add: share-based payment arrangements	204,085	926,613	574,739	184,875
Common Class A | Restricted stock
Reconciliation of basic to diluted loss per share
Add: share-based payment arrangements	4,515	220,531	402,950	285,088
Common Class A | Performance stock units
Reconciliation of basic to diluted loss per share
Add: share-based payment arrangements	71,492	92,658	172,690	117,491

Stockholders' Equity_Members'_3

Stockholders' Equity/Members' Interest - Equity Offerings (Details) - USD ($) $ / shares in Units, $ in Millions	Jan. 10, 2017	Sep. 29, 2018	Sep. 30, 2017	Dec. 30, 2017	Dec. 31, 2016
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Ownership percentage		97.00%	96.60%	96.80%	95.00%
Summit Holdings LP
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Noncontrolling interest elimination (as a percent)		3.00%		3.20%
Common Class A
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance (in shares)		110,350,594	97,554,278
Number of Summit LP units purchased by Company, newly issued units (in shares)		254,102
Exchanges during period (in shares)			1,255,266
Other (in shares)		1,049,856	1,177,200
Ending balance (in shares)		111,654,552	109,986,744
Common Class A | Follow on Public Offering
Summary Of Significant Accounting Policies And Recent Accounting Pronouncements [Line Items]
Value of stock issued, net of underwriting discounts	$ 237.6
Common stock issued (in shares)			10,000,000
Summit Materials, Inc. and Summit Holdings, LP
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance (in shares)		114,040,214	102,705,575
Other (in shares)		1,049,856	1,177,200
Ending balance (in shares)		115,090,070	113,882,775
Summit Materials, Inc. and Summit Holdings, LP | Follow on Public Offering
Summary Of Significant Accounting Policies And Recent Accounting Pronouncements [Line Items]
Common stock issued (in shares)			10,000,000
Summit Materials, Inc. and Summit Holdings, LP | Common Class A | Follow on Public Offering
Summary Of Significant Accounting Policies And Recent Accounting Pronouncements [Line Items]
Value of stock issued, net of underwriting discounts	$ 237.6
Common stock issued (in shares)	10,000,000
Offering price (in dollars per share)	$ 24.05
LP Units | Summit Holdings LP
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Number of LP Units outstanding (in shares)		3,689,620	5,151,297
Number of LP Units exchanged (in shares)		(254,102)	(1,255,266)
Number of LP Units outstanding (in shares)		3,435,518	3,896,031

Stockholders' Equity_Members'_4

Stockholders' Equity/Members' Interest - Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 29, 2018	Sep. 30, 2017
Changes in each component of accumulated other comprehensive loss
Beginning balance	$ 1,258,543
Foreign currency translation adjustment	(2,295)	$ 8,172
Liability adjustment		397
Income on cash flow hedges	1,043	368
Ending balance	1,344,860
Summit Materials, LLC
Changes in each component of accumulated other comprehensive loss
Foreign currency translation adjustment	(3,179)	8,498
Liability adjustment		413
Income on cash flow hedges	1,443	384
Accumulated Other Comprehensive Income (Loss)
Changes in each component of accumulated other comprehensive loss
Beginning balance	7,386	(2,249)
Ending balance	6,134	6,688
Accumulated Other Comprehensive Income (Loss) | Summit Materials, LLC
Changes in each component of accumulated other comprehensive loss
Beginning balance	(17,135)	(27,444)
Ending balance	(18,871)	(18,149)
Change in retirement plans
Changes in each component of accumulated other comprehensive loss
Beginning balance	2,364	1,450
Liability adjustment		397
Ending balance	2,364	1,847
Change in retirement plans | Summit Materials, LLC
Changes in each component of accumulated other comprehensive loss
Beginning balance	(6,053)	(7,181)
Liability adjustment		413
Ending balance	(6,053)	(6,768)
Foreign currency translation adjustment
Changes in each component of accumulated other comprehensive loss
Beginning balance	4,637	(3,106)
Foreign currency translation adjustment	(2,295)	8,172
Ending balance	2,342	5,066
Foreign currency translation adjustment | Summit Materials, LLC
Changes in each component of accumulated other comprehensive loss
Beginning balance	(10,022)	(17,790)
Foreign currency translation adjustment	(3,179)	8,498
Ending balance	(13,201)	(9,292)
Cash flow hedge adjustments
Changes in each component of accumulated other comprehensive loss
Beginning balance	385	(593)
Income on cash flow hedges	1,043	368
Ending balance	1,428	(225)
Cash flow hedge adjustments | Summit Materials, LLC
Changes in each component of accumulated other comprehensive loss
Beginning balance	(1,060)	(2,473)
Income on cash flow hedges	1,443	384
Ending balance	$ 383	$ (2,089)

Supplemental Cash Flow Inform_3

Supplemental Cash Flow Information - Schedule of Supplemental Cash Flow Information (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 29, 2018	Sep. 30, 2017
Cash payments:
Interest	$ 79,367	$ 71,117
Income taxes	3,362	1,841
Non cash financing activities:
Exchange of LP Units to shares of Class A common stock	7,499	34,831
Summit Materials, LLC
Cash payments:
Interest	79,367	71,117
Income taxes	$ 3,362	$ 1,841

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 29, 2018	Dec. 30, 2017
Loss Contingencies [Line Items]
Term of purchase commitments	1 year
Site Restoration Obligations
Loss Contingencies [Line Items]
Anticipated costs	$ 84	$ 67.9
Site Restoration Obligations | Other noncurrent liabilities
Loss Contingencies [Line Items]
Site restoration obligation, non-current	24.5	20.5
Site Restoration Obligations | Accrued expenses.
Loss Contingencies [Line Items]
Asset retirement obligation, current	$ 3.9	3.9
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	$ 84	67.9
Summit Materials, LLC | Site Restoration Obligations | Other noncurrent liabilities
Loss Contingencies [Line Items]
Site restoration obligation, non-current	24.5	20.5
Summit Materials, LLC | Site Restoration Obligations | Accrued expenses.
Loss Contingencies [Line Items]
Asset retirement obligation, current	$ 3.9	$ 3.9

Fair Value - Fair Value Measure

Fair Value - Fair Value Measurements (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 29, 2018	Sep. 30, 2017	Dec. 30, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Current portion of debt	$ 4,765		$ 4,765
Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Current portion of debt			4,800
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	3,011		594
Acquisition-related liabilities and other noncurrent liabilities - contingent consideration	$ 3,774		34,301
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		488
Acquisition-related liabilities and other noncurrent liabilities - cash flow hedge	0		492
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
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Current portion of debt	4,765		4,765
Summit Materials, LLC | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Current portion of debt	4,800
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	3,011		594
Acquisition-related liabilities and other noncurrent liabilities - contingent consideration	$ 3,774		34,301
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		488
Acquisition-related liabilities and other noncurrent liabilities - cash flow hedge	0		$ 492
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	Sep. 29, 2018	Dec. 30, 2017
Financial Instruments
Current portion of debt	$ 4,765	$ 4,765
Summit Materials, LLC
Financial Instruments
Current portion of debt	4,765	4,765
Level 2
Financial Instruments
Current portion of debt		4,800
Level 2 | Fair Value
Financial Instruments
Long-term debt	1,837,273	1,893,239
Level 2 | Carrying Value
Financial Instruments
Long-term debt	1,828,041	1,832,455
Level 2 | Summit Materials, LLC
Financial Instruments
Current portion of debt	4,800
Level 2 | Summit Materials, LLC | Fair Value
Financial Instruments
Long-term debt	1,837,273	1,893,239
Level 2 | Summit Materials, LLC | Carrying Value
Financial Instruments
Long-term debt	1,828,041	1,832,455
Level 3 | Fair Value
Financial Instruments
Current portion of deferred consideration and noncompete obligations	11,137	13,493
Long term portion of deferred consideration and noncompete obligations	25,355	23,834
Level 3 | Carrying Value
Financial Instruments
Current portion of deferred consideration and noncompete obligations	11,137	13,493
Long term portion of deferred consideration and noncompete obligations	25,355	23,834
Level 3 | Summit Materials, LLC | Fair Value
Financial Instruments
Current portion of deferred consideration and noncompete obligations	8,637	10,993
Long term portion of deferred consideration and noncompete obligations	21,411	17,938
Level 3 | Summit Materials, LLC | Carrying Value
Financial Instruments
Current portion of deferred consideration and noncompete obligations	8,637	10,993
Long term portion of deferred consideration and noncompete obligations	$ 21,411	$ 17,938

Segment Information - Financial

Segment Information - Financial Data (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 29, 2018USD ($)	Sep. 30, 2017USD ($)	Sep. 29, 2018USD ($)segment	Sep. 30, 2017USD ($)	Dec. 30, 2017USD ($)
Segment Reporting Information [Line Items]
Number of operating segments | segment			3
Number of reportable segments | segment			3
Total revenue	$ 694,661	$ 634,181	$ 1,609,972	$ 1,442,551
Income (loss) from operations before taxes	94,757	(414,046)	71,206	(415,809)
Interest expense	28,889	28,921	86,616	79,876
Depreciation, depletion and amortization	53,494	48,483	149,439	132,374
Accretion	480	486	1,224	1,382
Loss on debt financings	0	0	149	190
Tax receivable agreement expense	0	501,752	0	503,277
Gain on sale of business	(12,108)	0	(12,108)	0
Transaction costs	1,260	2,581	3,817	6,474
Non-cash compensation	5,643	4,724	19,833	14,148
Other	(409)	(200)	(7,316)	(346)
Total Adjusted EBITDA	172,006	172,701	312,860	321,566
Total purchases of property, plant and equipment			183,752	147,478
Total depreciation, depletion, amortization and accretion	53,974	48,969	150,663	133,756
Total assets	3,896,334		3,896,334		$ 3,787,333
West
Segment Reporting Information [Line Items]
Total revenue	367,912	327,917	871,338	746,991
Gain on sale of business	(12,108)
East
Segment Reporting Information [Line Items]
Total revenue	232,777	204,990	525,270	466,222
Cement
Segment Reporting Information [Line Items]
Total revenue	93,972	101,274	213,364	229,338
Operating segment
Segment Reporting Information [Line Items]
Total purchases of property, plant and equipment			177,806	142,483
Total depreciation, depletion, amortization and accretion	53,400	48,350	148,744	131,816
Total assets	3,551,610		3,551,610		3,131,724
Operating segment | West
Segment Reporting Information [Line Items]
Total Adjusted EBITDA	73,916	76,637	151,316	152,856
Total purchases of property, plant and equipment			104,217	64,257
Total depreciation, depletion, amortization and accretion	23,289	18,907	68,029	51,989
Total assets	1,422,966		1,422,966		1,225,463
Operating segment | East
Segment Reporting Information [Line Items]
Total Adjusted EBITDA	58,305	56,397	100,497	99,511
Total purchases of property, plant and equipment			51,968	52,920
Total depreciation, depletion, amortization and accretion	19,429	17,628	54,982	49,939
Total assets	1,229,567		1,229,567		1,035,609
Operating segment | Cement
Segment Reporting Information [Line Items]
Total Adjusted EBITDA	44,299	46,860	82,626	93,328
Total purchases of property, plant and equipment			21,621	25,306
Total depreciation, depletion, amortization and accretion	10,682	11,815	25,733	29,888
Total assets	899,077		899,077		870,652
Corporate, Non-Segment
Segment Reporting Information [Line Items]
Total Adjusted EBITDA	(4,514)	(7,193)	(21,579)	(24,129)
Total purchases of property, plant and equipment			5,946	4,995
Total depreciation, depletion, amortization and accretion	574	619	1,919	1,940
Total assets	344,724		$ 344,724		655,609
Summit Materials, LLC
Segment Reporting Information [Line Items]
Number of operating segments | segment			3
Total revenue	694,661	634,181	$ 1,609,972	1,442,551
Income (loss) from operations before taxes	94,926	87,919	71,756	88,149
Interest expense	28,720	28,708	86,066	79,195
Depreciation, depletion and amortization	53,494	48,483	149,439	132,374
Accretion	480	486	1,224	1,382
Loss on debt financings	0	0	149	190
Gain on sale of business	(12,108)	0	(12,108)	0
Transaction costs	1,260	2,581	3,817	6,474
Non-cash compensation	5,643	4,724	19,833	14,148
Other	(409)	(200)	(7,316)	(346)
Total Adjusted EBITDA	172,006	172,701	312,860	321,566
Total purchases of property, plant and equipment			183,752	147,478
Total depreciation, depletion, amortization and accretion	53,974	48,969	150,663	133,756
Total assets	3,629,802		3,629,802		3,504,241
Summit Materials, LLC | West
Segment Reporting Information [Line Items]
Total revenue	367,912	327,917	871,338	746,991
Gain on sale of business			(12,100)
Summit Materials, LLC | East
Segment Reporting Information [Line Items]
Total revenue	232,777	204,990	525,270	466,222
Summit Materials, LLC | Cement
Segment Reporting Information [Line Items]
Total revenue	93,972	101,274	213,364	229,338
Summit Materials, LLC | Operating segment
Segment Reporting Information [Line Items]
Total purchases of property, plant and equipment			177,806	142,483
Total depreciation, depletion, amortization and accretion	53,400	48,350	148,744	131,816
Total assets	3,551,610		3,551,610		3,131,724
Summit Materials, LLC | Operating segment | West
Segment Reporting Information [Line Items]
Total Adjusted EBITDA	73,916	76,637	151,316	152,856
Total purchases of property, plant and equipment			104,217	64,257
Total depreciation, depletion, amortization and accretion	23,289	18,907	68,029	51,989
Total assets	1,422,966		1,422,966		1,225,463
Summit Materials, LLC | Operating segment | East
Segment Reporting Information [Line Items]
Total Adjusted EBITDA	58,305	56,397	100,497	99,511
Total purchases of property, plant and equipment			51,968	52,920
Total depreciation, depletion, amortization and accretion	19,429	17,628	54,982	49,939
Total assets	1,229,567		1,229,567		1,035,609
Summit Materials, LLC | Operating segment | Cement
Segment Reporting Information [Line Items]
Total Adjusted EBITDA	44,299	46,860	82,626	93,328
Total purchases of property, plant and equipment			21,621	25,306
Total depreciation, depletion, amortization and accretion	10,682	11,815	25,733	29,888
Total assets	899,077		899,077		870,652
Summit Materials, LLC | Corporate, Non-Segment
Segment Reporting Information [Line Items]
Total Adjusted EBITDA	(4,514)	(7,193)	(21,579)	(24,129)
Total purchases of property, plant and equipment			5,946	4,995
Total depreciation, depletion, amortization and accretion	574	$ 619	1,919	$ 1,940
Total assets	$ 78,192		$ 78,192		$ 372,517

Guarantor and Non-Guarantor F_3

Guarantor and Non-Guarantor Financial Information - Schedule of Condensed Consolidating Balance Sheets (Details) - USD ($) $ in Thousands	Sep. 29, 2018	Dec. 30, 2017	Sep. 30, 2017	Dec. 31, 2016
Current assets:
Cash and cash equivalents	$ 64,930	$ 383,556	$ 287,082	$ 143,392
Accounts receivable, net	301,670	198,330
Cost and estimated earnings in excess of billings	47,629	9,512
Inventories	229,761	184,439
Other current assets	15,690	7,764
Total current assets	659,680	783,601
Property, plant and equipment, net	1,751,810	1,615,424
Goodwill	1,147,588	1,036,320
Intangible assets	18,892	16,833
Other assets	50,832	51,063
Total assets	3,896,334	3,787,333
Current liabilities:
Current portion of debt	4,765	4,765
Current portion of acquisition-related liabilities	14,148	14,087
Accounts payable	140,174	98,744
Accrued expenses	114,257	116,629
Billings in excess of costs and estimated earnings	13,072	15,750
Total current liabilities	286,416	249,975
Long-term debt	1,808,190	1,810,833
Acquisition-related liabilities	29,129	58,135
Other noncurrent liabilities	80,577	65,329
Total liabilities	2,537,464	2,515,612
Total liabilities and stockholders’ equity	3,896,334	3,787,333
Summit Materials, LLC
Current assets:
Cash and cash equivalents	64,930	383,556	287,082	142,672
Accounts receivable, net	301,670	198,330
Intercompany receivables	0	0
Cost and estimated earnings in excess of billings	47,629	9,512
Inventories	229,761	184,439
Other current assets	15,690	7,764
Total current assets	659,680	783,601
Property, plant and equipment, net	1,751,810	1,615,424
Goodwill	1,148,588	1,037,320
Intangible assets	18,892	16,833
Other assets	50,832	51,063
Total assets	3,629,802	3,504,241
Current liabilities:
Current portion of debt	4,765	4,765
Current portion of acquisition-related liabilities	11,648	11,587
Accounts payable	141,480	100,637
Accrued expenses	114,488	116,274
Intercompany payables	0	0
Billings in excess of costs and estimated earnings	13,072	15,750
Total current liabilities	285,453	249,013
Long-term debt	1,808,190	1,810,833
Acquisition-related liabilities	25,185	52,239
Other noncurrent liabilities	121,717	100,562
Total liabilities	2,240,545	2,212,647
Total member's interest	1,389,257	1,291,594
Total liabilities and stockholders’ equity	3,629,802	3,504,241
Summit Materials, LLC | Eliminations
Current assets:
Cash and cash equivalents	(16,252)	(12,372)	(14,572)	(10,666)
Accounts receivable, net	(179)	0
Intercompany receivables	(1,032,976)	(1,058,048)
Cost and estimated earnings in excess of billings	0	0
Inventories	0	0
Other current assets	0	0
Total current assets	(1,049,407)	(1,070,420)
Property, plant and equipment, net	0	0
Goodwill	0	0
Intangible assets	0	0
Other assets	(3,330,364)	(3,003,593)
Total assets	(4,379,771)	(4,074,013)
Current liabilities:
Current portion of debt	0	0
Current portion of acquisition-related liabilities	0	0
Accounts payable	(179)	0
Accrued expenses	(16,252)	(12,372)
Intercompany payables	(1,032,976)	(1,058,048)
Billings in excess of costs and estimated earnings	0	0
Total current liabilities	(1,049,407)	(1,070,420)
Long-term debt	0	0
Acquisition-related liabilities	0	0
Other noncurrent liabilities	(171,318)	(171,318)
Total liabilities	(1,220,725)	(1,241,738)
Total member's interest	(3,159,046)	(2,832,275)
Total liabilities and stockholders’ equity	(4,379,771)	(4,074,013)
Summit Materials, LLC | Issuers | Reportable Legal Entities
Current assets:
Cash and cash equivalents	75,529	370,741	283,331	133,862
Accounts receivable, net	289	0
Intercompany receivables	523,663	573,301
Cost and estimated earnings in excess of billings	0	0
Inventories	0	0
Other current assets	1,758	1,167
Total current assets	601,239	945,209
Property, plant and equipment, net	12,556	9,259
Goodwill	0	0
Intangible assets	0	0
Other assets	3,219,616	2,890,674
Total assets	3,833,411	3,845,142
Current liabilities:
Current portion of debt	4,765	4,765
Current portion of acquisition-related liabilities	0	0
Accounts payable	4,580	3,976
Accrued expenses	42,095	47,047
Intercompany payables	580,768	684,057
Billings in excess of costs and estimated earnings	0	0
Total current liabilities	632,208	739,845
Long-term debt	1,808,190	1,810,833
Acquisition-related liabilities	0	0
Other noncurrent liabilities	3,756	2,870
Total liabilities	2,444,154	2,553,548
Total member's interest	1,389,257	1,291,594
Total liabilities and stockholders’ equity	3,833,411	3,845,142
Summit Materials, LLC | 100% Owned Guarantors | Reportable Legal Entities
Current assets:
Cash and cash equivalents	1,946	10,254	2,199	4,820
Accounts receivable, net	279,071	183,139
Intercompany receivables	509,313	484,747
Cost and estimated earnings in excess of billings	45,732	9,264
Inventories	227,047	180,283
Other current assets	12,986	6,354
Total current assets	1,076,095	874,041
Property, plant and equipment, net	1,678,923	1,569,118
Goodwill	1,089,169	976,206
Intangible assets	18,892	16,833
Other assets	160,131	162,711
Total assets	4,023,210	3,598,909
Current liabilities:
Current portion of debt	0	0
Current portion of acquisition-related liabilities	11,648	11,587
Accounts payable	121,519	89,912
Accrued expenses	85,922	79,372
Intercompany payables	438,378	369,918
Billings in excess of costs and estimated earnings	12,417	15,349
Total current liabilities	669,884	566,138
Long-term debt	0	0
Acquisition-related liabilities	25,185	52,239
Other noncurrent liabilities	213,054	193,801
Total liabilities	908,123	812,178
Total member's interest	3,115,087	2,786,731
Total liabilities and stockholders’ equity	4,023,210	3,598,909
Summit Materials, LLC | Non-Guarantors | Reportable Legal Entities
Current assets:
Cash and cash equivalents	3,707	14,933	$ 16,124	$ 14,656
Accounts receivable, net	22,489	15,191
Intercompany receivables	0	0
Cost and estimated earnings in excess of billings	1,897	248
Inventories	2,714	4,156
Other current assets	946	243
Total current assets	31,753	34,771
Property, plant and equipment, net	60,331	37,047
Goodwill	59,419	61,114
Intangible assets	0	0
Other assets	1,449	1,271
Total assets	152,952	134,203
Current liabilities:
Current portion of debt	0	0
Current portion of acquisition-related liabilities	0	0
Accounts payable	15,560	6,749
Accrued expenses	2,723	2,227
Intercompany payables	13,830	4,073
Billings in excess of costs and estimated earnings	655	401
Total current liabilities	32,768	13,450
Long-term debt	0	0
Acquisition-related liabilities	0	0
Other noncurrent liabilities	76,225	75,209
Total liabilities	108,993	88,659
Total member's interest	43,959	45,544
Total liabilities and stockholders’ equity	$ 152,952	$ 134,203

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		9 Months Ended
	Sep. 29, 2018	Sep. 30, 2017	Sep. 29, 2018	Sep. 30, 2017
Condensed Consolidating Statements of Operations
Revenue	$ 694,661	$ 634,181	$ 1,609,972	$ 1,442,551
Cost of revenue (excluding items shown separately below)	471,803	409,545	1,130,596	963,021
Depreciation, depletion, amortization and accretion	53,974	48,969	150,663	133,756
Operating income	108,167	113,911	133,921	163,571
Gain on sale of business	(12,108)	0	(12,108)	0
Income (loss) from operations before taxes	94,757	(414,046)	71,206	(415,809)
Income tax expense (benefit)	20,765	(498,333)	16,249	(497,076)
Net income	73,992	84,287	54,957	81,267
Net income attributable to Summit Inc.	71,289	81,264	53,069	78,820
Comprehensive income (loss) income attributable to member of Summit Materials, LLC	70,037	85,679	51,817	87,757
Summit Materials, LLC
Condensed Consolidating Statements of Operations
Revenue	694,661	634,181	1,609,972	1,442,551
Cost of revenue (excluding items shown separately below)	471,803	409,545	1,130,596	963,021
General and administrative expenses	60,717	61,756	194,792	182,203
Depreciation, depletion, amortization and accretion	53,974	48,969	150,663	133,756
Operating income	108,167	113,911	133,921	163,571
Other (income) expense, net	(3,371)	(2,716)	(11,793)	(3,773)
Interest expense (income)	28,720	28,708	86,066	79,195
Gain on sale of business	(12,108)	0	(12,108)	0
Income (loss) from operations before taxes	94,926	87,919	71,756	88,149
Income tax expense (benefit)	4,499	5,286	3,323	6,543
Net income	90,427	82,633	68,433	81,606
Net income (loss) attributable to noncontrolling interest	0	59	0	(27)
Net income attributable to Summit Inc.	90,427	82,574	68,433	81,633
Comprehensive income (loss) income attributable to member of Summit Materials, LLC	92,484	87,160	66,697	90,928
Summit Materials, LLC | Eliminations
Condensed Consolidating Statements of Operations
Revenue	(1,548)	(1,473)	(4,585)	(4,635)
Cost of revenue (excluding items shown separately below)	(1,548)	(1,473)	(4,585)	(4,635)
General and administrative expenses	0	0	0	0
Depreciation, depletion, amortization and accretion	0	0	0	0
Operating income	0	0	0	0
Other (income) expense, net	132,266	125,484	203,534	203,165
Interest expense (income)	0	0	0	0
Gain on sale of business	0		0
Income (loss) from operations before taxes	(132,266)	(125,484)	(203,534)	(203,165)
Income tax expense (benefit)	0	0	0	0
Net income		(125,484)		(203,165)
Net income (loss) attributable to noncontrolling interest		59		(27)
Net income attributable to Summit Inc.	(132,266)	(125,543)	(203,534)	(203,138)
Comprehensive income (loss) income attributable to member of Summit Materials, LLC	(130,209)	(120,957)	(205,270)	(193,843)
Issuers | Summit Materials, LLC | Reportable Legal Entities
Condensed Consolidating Statements of Operations
Revenue	0	0	0	0
Cost of revenue (excluding items shown separately below)	0	0	0	0
General and administrative expenses	10,951	15,011	45,175	44,718
Depreciation, depletion, amortization and accretion	574	619	1,919	1,940
Operating income	(11,525)	(15,630)	(47,094)	(46,658)
Other (income) expense, net	(132,382)	(126,386)	(204,677)	(204,877)
Interest expense (income)	29,396	28,182	87,924	76,586
Gain on sale of business	0		0
Income (loss) from operations before taxes	91,461	82,574	69,659	81,633
Income tax expense (benefit)	1,034	0	1,226	0
Net income		82,574		81,633
Net income (loss) attributable to noncontrolling interest		0		0
Net income attributable to Summit Inc.	90,427	82,574	68,433	81,633
Comprehensive income (loss) income attributable to member of Summit Materials, LLC	92,484	87,160	66,697	90,928
100% Owned Guarantors | Summit Materials, LLC | Reportable Legal Entities
Condensed Consolidating Statements of Operations
Revenue	668,145	606,046	1,548,960	1,384,956
Cost of revenue (excluding items shown separately below)	452,394	389,716	1,087,150	922,024
General and administrative expenses	46,910	44,373	141,372	131,770
Depreciation, depletion, amortization and accretion	52,213	47,032	145,135	128,851
Operating income	116,628	124,925	175,303	202,311
Other (income) expense, net	(3,019)	(1,569)	(10,563)	(1,561)
Interest expense (income)	(1,882)	(670)	(5,447)	(533)
Gain on sale of business	(12,108)		(12,108)
Income (loss) from operations before taxes	133,637	127,164	203,421	204,405
Income tax expense (benefit)	2,898	4,397	1,481	5,119
Net income		122,767		199,286
Net income (loss) attributable to noncontrolling interest		0		0
Net income attributable to Summit Inc.	130,739	122,767	201,940	199,286
Comprehensive income (loss) income attributable to member of Summit Materials, LLC	130,652	122,555	200,497	198,489
Non-Guarantors | Summit Materials, LLC | Reportable Legal Entities
Condensed Consolidating Statements of Operations
Revenue	28,064	29,608	65,597	62,230
Cost of revenue (excluding items shown separately below)	20,957	21,302	48,031	45,632
General and administrative expenses	2,856	2,372	8,245	5,715
Depreciation, depletion, amortization and accretion	1,187	1,318	3,609	2,965
Operating income	3,064	4,616	5,712	7,918
Other (income) expense, net	(236)	(245)	(87)	(500)
Interest expense (income)	1,206	1,196	3,589	3,142
Gain on sale of business	0		0
Income (loss) from operations before taxes	2,094	3,665	2,210	5,276
Income tax expense (benefit)	567	889	616	1,424
Net income		2,776		3,852
Net income (loss) attributable to noncontrolling interest		0		0
Net income attributable to Summit Inc.	1,527	2,776	1,594	3,852
Comprehensive income (loss) income attributable to member of Summit Materials, LLC	$ (443)	$ (1,598)	$ 4,773	$ (4,646)

Guarantor and Non-Guarantor F_5

Guarantor and Non-Guarantor Financial Information - Schedule of Condensed Consolidating Statements of Cash Flows (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 29, 2018	Sep. 30, 2017
Condensed Consolidating Statements of Operations
Net cash (used in) provided by operating activities	$ 70,557	$ 132,433
Cash flow from investing activities:
Acquisitions, net of cash acquired	(210,894)	(371,479)
Purchase of property, plant and equipment	(183,752)	(147,478)
Proceeds from the sale of property, plant, and equipment	18,426	13,290
Proceeds from sale of business	21,564	0
Other	2,660	182
Net cash used for investing activities	(351,996)	(505,485)
Cash flow from financing activities:
Capital issuance costs	0	(627)
Net proceeds from debt issuance	64,500	302,000
Payments on long-term debt	(79,027)	(12,887)
Payments on acquisition-related liabilities	(35,321)	(22,616)
Financing costs	(550)	(5,317)
Distributions from partnership	(69)	(109)
Other	(1,913)	(846)
Net cash (used in) provided by financing activities	(36,765)	516,008
Impact of foreign currency on cash	(422)	734
Net (decrease) increase in cash	(318,626)	143,690
Cash and cash equivalents—beginning of period	383,556	143,392
Cash and cash equivalents—end of period	64,930	287,082
Summit Materials, LLC
Condensed Consolidating Statements of Operations
Net cash (used in) provided by operating activities	70,557	132,895
Cash flow from investing activities:
Acquisitions, net of cash acquired	(210,894)	(371,479)
Purchase of property, plant and equipment	(183,752)	(147,478)
Proceeds from the sale of property, plant, and equipment	18,426	13,290
Proceeds from sale of business	21,564	0
Other	2,660	182
Net cash used for investing activities	(351,996)	(505,485)
Cash flow from financing activities:
Proceeds from investment by member	15,615	256,667
Capital issuance costs	0	(627)
Net proceeds from debt issuance	64,500	302,000
Loans received from and payments made on loans from other Summit Companies	0	0
Payments on long-term debt	(79,027)	(12,887)
Payments on acquisition-related liabilities	(32,821)	(20,116)
Financing costs	(550)	(5,317)
Distributions from partnership	(2,569)	(2,609)
Other	(1,913)	(845)
Net cash (used in) provided by financing activities	(36,765)	516,266
Impact of foreign currency on cash	(422)	734
Net (decrease) increase in cash	(318,626)	144,410
Cash and cash equivalents—beginning of period	383,556	142,672
Cash and cash equivalents—end of period	64,930	287,082
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
Proceeds from sale of business	0
Other	0	0
Net cash used for investing activities	0	0
Cash flow from financing activities:
Proceeds from investment by member	0	0
Capital issuance costs		0
Net proceeds from debt issuance	0	0
Loans received from and payments made on loans from other Summit Companies	(3,880)	(3,906)
Payments on long-term debt	0	0
Payments on acquisition-related liabilities	0	0
Financing costs	0	0
Distributions from partnership	0	0
Other	0	0
Net cash (used in) provided by financing activities	(3,880)	(3,906)
Impact of foreign currency on cash	0	0
Net (decrease) increase in cash	(3,880)	(3,906)
Cash and cash equivalents—beginning of period	(12,372)	(10,666)
Cash and cash equivalents—end of period	(16,252)	(14,572)
Issuers | Summit Materials, LLC | Reportable Legal Entities
Condensed Consolidating Statements of Operations
Net cash (used in) provided by operating activities	(107,736)	(92,840)
Cash flow from investing activities:
Acquisitions, net of cash acquired	0	(24,538)
Purchase of property, plant and equipment	(5,946)	(4,994)
Proceeds from the sale of property, plant, and equipment	0	0
Proceeds from sale of business	0
Other	0	0
Net cash used for investing activities	(5,946)	(29,532)
Cash flow from financing activities:
Proceeds from investment by member	(112,386)	(3,409)
Capital issuance costs		(627)
Net proceeds from debt issuance	64,500	302,000
Loans received from and payments made on loans from other Summit Companies	(60,387)	(10,787)
Payments on long-term debt	(69,265)	(6,874)
Payments on acquisition-related liabilities	0	0
Financing costs	(550)	(5,317)
Distributions from partnership	(2,569)	(2,609)
Other	(873)	(536)
Net cash (used in) provided by financing activities	(181,530)	271,841
Impact of foreign currency on cash	0	0
Net (decrease) increase in cash	(295,212)	149,469
Cash and cash equivalents—beginning of period	370,741	133,862
Cash and cash equivalents—end of period	75,529	283,331
100% Owned Guarantors | Summit Materials, LLC | Reportable Legal Entities
Condensed Consolidating Statements of Operations
Net cash (used in) provided by operating activities	173,597	198,890
Cash flow from investing activities:
Acquisitions, net of cash acquired	(210,894)	(321,340)
Purchase of property, plant and equipment	(156,016)	(137,505)
Proceeds from the sale of property, plant, and equipment	18,257	13,231
Proceeds from sale of business	21,564
Other	2,660	182
Net cash used for investing activities	(324,429)	(445,432)
Cash flow from financing activities:
Proceeds from investment by member	128,001	249,359
Capital issuance costs		0
Net proceeds from debt issuance	0	0
Loans received from and payments made on loans from other Summit Companies	58,052	20,975
Payments on long-term debt	(9,701)	(6,009)
Payments on acquisition-related liabilities	(32,821)	(20,116)
Financing costs	0	0
Distributions from partnership	0	0
Other	(1,007)	(288)
Net cash (used in) provided by financing activities	142,524	243,921
Impact of foreign currency on cash	0	0
Net (decrease) increase in cash	(8,308)	(2,621)
Cash and cash equivalents—beginning of period	10,254	4,820
Cash and cash equivalents—end of period	1,946	2,199
Non-Guarantors | Summit Materials, LLC | Reportable Legal Entities
Condensed Consolidating Statements of Operations
Net cash (used in) provided by operating activities	4,696	26,845
Cash flow from investing activities:
Acquisitions, net of cash acquired	0	(25,601)
Purchase of property, plant and equipment	(21,790)	(4,979)
Proceeds from the sale of property, plant, and equipment	169	59
Proceeds from sale of business	0
Other	0	0
Net cash used for investing activities	(21,621)	(30,521)
Cash flow from financing activities:
Proceeds from investment by member	0	10,717
Capital issuance costs		0
Net proceeds from debt issuance	0	0
Loans received from and payments made on loans from other Summit Companies	6,215	(6,282)
Payments on long-term debt	(61)	(4)
Payments on acquisition-related liabilities	0	0
Financing costs	0	0
Distributions from partnership	0	0
Other	(33)	(21)
Net cash (used in) provided by financing activities	6,121	4,410
Impact of foreign currency on cash	(422)	734
Net (decrease) increase in cash	(11,226)	1,468
Cash and cash equivalents—beginning of period	14,933	14,656
Cash and cash equivalents—end of period	$ 3,707	$ 16,124