Heritage-Crystal Clean (HCCI) 10-Q 3 May 18 2018 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Mar. 24, 2018	May 01, 2018
Document and Entity Information [Abstract]
Entity Registrant Name	Heritage-Crystal Clean, Inc.
Entity Central Index Key	1,403,431
Current Fiscal Year End Date	--12-29
Entity Filer Category	Accelerated Filer
Document Type	10-Q
Document Period End Date	Mar. 24, 2018
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	Q1
Amendment Flag	false
Entity Common Stock, Shares Outstanding		23,015,552

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 24, 2018	Dec. 30, 2017
Current Assets:
Cash and cash equivalents	$ 37,557	$ 41,889
Accounts receivable - net	46,883	45,491
Inventory - net	25,394	21,639
Other current assets	5,122	5,895
Total Current Assets	114,956	114,914
Property, plant and equipment - net	128,504	128,119
Equipment at customers - net	23,473	23,312
Software and intangible assets - net	16,005	16,732
Goodwill	31,580	31,580
Total Assets	314,518	314,657
Current Liabilities:
Accounts payable	27,849	25,568
Contract liabilities - net	237	0
Accrued salaries, wages, and benefits	4,535	6,386
Taxes payable	5,898	5,787
Other current liabilities	2,562	2,690
Total Current Liabilities	41,081	40,431
Long-term debt	28,814	28,744
Deferred income taxes	9,170	9,556
Total Liabilities	79,065	78,731
STOCKHOLDERS' EQUITY:
Common stock - 26,000,000 shares authorized at $0.01 par value, 23,010,733 and 22,891,674 shares issued and outstanding at March 24, 2018 and December 30, 2017, respectively	230	229
Additional paid-in capital	193,536	193,640
Retained earnings	40,971	41,359
Total Heritage-Crystal Clean, Inc. Stockholders' Equity	234,737	235,228
Noncontrolling interest	716	698
Total Equity	235,453	235,926
Total Liabilities and Stockholders' Equity	$ 314,518	$ 314,657

Condensed Consolidated Balance3

Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	Mar. 24, 2018	Dec. 30, 2017
Statement of Financial Position [Abstract]
Common stock, shares authorized	26,000,000	26,000,000
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares issued	23,010,733	22,891,674
Common stock, shares outstanding	23,010,733	22,891,674

Condensed Consolidated Statemen

Condensed Consolidated Statements of Income - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 24, 2018	Mar. 25, 2017
Revenues
Product revenues	$ 29,010	$ 26,980
Service revenues	54,137	53,473
Total revenues	83,147	80,453
Operating expenses
Operating costs	68,386	61,290
Selling, general, and administrative expenses	11,022	12,341
Depreciation and amortization	3,643	4,132
Other expense (income) - net	389	(5,006)
Operating (loss) income	(293)	7,696
Interest expense – net	245	87
(Loss) income before income taxes	(538)	7,609
(Benefit from) provision for income taxes	(436)	2,792
Net (loss) income	(102)	4,817
Income attributable to noncontrolling interest	18	53
Net (loss) income attributable to Heritage-Crystal Clean, Inc. common stockholders	$ (120)	$ 4,764
Net (loss) income per share: basic (in dollars per share)	$ (0.01)	$ 0.21
Net (loss) income per share: diluted (in dollars per share)	$ (0.01)	$ 0.21
Number of weighted average shares outstanding: basic (in shares)	22,962	22,353
Number of weighted average shares outstanding: diluted (in shares)	22,962	22,892

Condensed Consolidated Stateme5

Condensed Consolidated Statement of Stockholders' Equity - USD ($) $ in Thousands	Total	Common stock	Additional Paid–in Capital	Retained Earnings	Total Heritage-Crystal Clean, Inc. Stockholders' Equity	Non-controlling Interest
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Adjustment from adopting ASC 606	$ (268)			$ (268)	$ (268)
Beginning balance (in shares) at Dec. 30, 2017	22,891,674	22,891,674
Beginning balance at Dec. 30, 2017	$ 235,926	$ 229	$ 193,640	41,359	235,228	$ 698
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (loss) income	(102)			(120)	(120)	18
Issuance of common stock – ESPP (in shares)		4,822
Issuance of common stock – ESPP	100		100		100
Share-based compensation (in shares)		114,237
Share-based compensation	828	$ 1	827		828
Share repurchases to satisfy tax withholding obligations	$ (1,031)		(1,031)		(1,031)
Ending balance (in shares) at Mar. 24, 2018	23,010,733	23,010,733
Ending balance at Mar. 24, 2018	$ 235,453	$ 230	$ 193,536	$ 40,971	$ 234,737	$ 716

Condensed Consolidated Stateme6

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 24, 2018	Mar. 25, 2017
Cash flows from Operating Activities:
Net (loss) income	$ (102)	$ 4,817
Adjustments to reconcile net (loss) income to net cash (used in) provided by operating activities:
Depreciation and amortization	3,643	4,132
Bad debt provision	286	(28)
Share-based compensation	828	667
Deferred taxes	(386)	2,710
Other, net	74	435
Changes in operating assets and liabilities:
(Increase) decrease in accounts receivable	(1,678)	4,375
Increase in inventory	(3,755)	(1,166)
Decrease in other current assets	773	1,410
Increase (decrease) in accounts payable	2,344	(2,628)
Decrease in accrued liabilities	(2,564)	(2,670)
Cash (used in) provided by operating activities	(537)	12,054
Cash flows from Investing Activities:
Capital expenditures	(3,568)	(3,313)
Proceeds from the disposal of assets	55	20
Cash used in investing activities	(3,513)	(3,293)
Cash flows from Financing Activities:
Payments on Term loan	0	(64,195)
Proceeds from new Term Loan	0	30,000
Proceeds under revolving credit facility	0	4,000
Payments of revolving credit facility	0	(4,000)
Proceeds from the exercise of stock options	0	1,018
Share repurchases to satisfy tax withholding obligations	(382)	(356)
Proceeds from the issuance of common stock	100	101
Payments of debt issuance costs	0	(1,051)
Cash used in financing activities	(282)	(34,483)
Net decrease in cash and cash equivalents	(4,332)	(25,722)
Cash and cash equivalents, beginning of period	41,889	36,610
Cash and cash equivalents, end of period	37,557	10,888
Supplemental disclosure of cash flow information:
Income taxes paid	2	0
Cash paid for interest	249	481
Supplemental disclosure of non-cash information:
Payables for share-based tax withholdings	649	0
Payables for construction in progress	$ 451	$ 0

Organization and Nature of Oper

Organization and Nature of Operations	3 Months Ended
	Mar. 24, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization and Nature of Operations	ORGANIZATION AND NATURE OF OPERATIONS Heritage-Crystal Clean, Inc., a Delaware corporation and its subsidiaries (collectively the “Company”), provides parts cleaning, hazardous and non-hazardous containerized waste, used oil collection, vacuum, antifreeze recycling and field services primarily to small and mid-sized industrial and vehicle maintenance customers. The Company owns and operates a used oil re-refinery where it re-refines used oils and sells high quality base oil for lubricants as well as other re-refinery products. The Company also has multiple locations where it dehydrates used oil. The oil processed at these locations is sold as recycled fuel oil. The Company also operates multiple wastewater treatment plants and antifreeze recycling facilities at which it produces virgin-quality antifreeze. The Company operates in the United States and Ontario, Canada. The Company conducts its primary business operations through Heritage-Crystal Clean, LLC, its wholly owned subsidiary, and all intercompany balances have been eliminated in consolidation. The Company has two reportable segments: "Environmental Services" and "Oil Business." The Environmental Services segment consists of the Company's parts cleaning, containerized waste management, vacuum truck services, antifreeze recycling activities, and field services. The Oil Business segment consists of the Company's used oil collection, recycled fuel oil sales, used oil re-refining activities, and used oil filter removal and disposal services. No customer represented greater than 10% of consolidated revenues for any of the periods presented. There were no intersegment revenues. Both segments operate in the United States, and the Environmental Services segment also operates, to an immaterial degree, in Ontario, Canada. The Company’s fiscal year ends on the Saturday closest to December 31. The most recent fiscal year ended on December 30, 2017 . Each of the Company's first three fiscal quarters consists of twelve weeks while the last fiscal quarter consists of sixteen or seventeen weeks. In the Company's Environmental Services segment, product revenues include sales of solvent, machines, absorbent, accessories, and antifreeze; service revenues include servicing of parts cleaning machines, drum waste removal services, vacuum truck services, field services, and other services. In the Company's Oil Business segment, product revenues include sales of re-refined base oil, recycled fuel oil, used oil, and other products; service revenues include revenues from used oil collection activities, collecting and disposing of waste water and removal and disposal of used oil filters. Due to the Company's integrated business model, it is impracticable to separately present costs of tangible products and costs of services.

Summary of Significant Accounti

Summary of Significant Accounting Policies	3 Months Ended
	Mar. 24, 2018
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES The Company's significant accounting policies are described in Note 2, "Summary of Significant Accounting Policies," in the Company's Annual Report on Form 10-K for the fiscal year ended December 30, 2017. There have been no material changes in these policies or their application with the exception of revenue recognition. See footnote 3 - Revenue for more information. Recently Issued Accounting Pronouncements Standard Issuance Date Description Our Effective Date Effect on the Financial Statements ASU 2016-02 February 2016 This update was issued to increase transparency and comparability among organizations by recognizing lease assets and lease liabilities on the balance sheet and disclosing key information about leasing arrangements. Early application of the amendments in this update is permitted for all entities. January 4, 2019 The Company is currently evaluating the effect that implementation of this update will have on its consolidated financial position and results of operations. The Company anticipates that implementation of this standard will result in an increase to assets and an increase to liabilities. To date, certain personnel have attended technical training concerning this new lease accounting standard. Recently Issued Accounting Standards Adopted Standard Issuance Date Description Effective Date Effect on the Financial Statements ASU 2014-09 “Revenue from Contracts with Customers (Topic 606),” ASU 2014-15 “Revenue from Contracts with Customers (Topic 606): Deferral of the Effective Date,” ASU 2016-08 “Revenue from Contracts with Customers (Topic 606): Principal versus Agent Considerations (Reporting Revenue Gross versus Net),” ASU 2016-10 “ Revenue from Contracts with Customers (Topic 606): Identifying Performance Obligations and Licensing,” and ASU 2016-12 “Revenue from Contracts with Customers (Topic 606): Narrow-Scope Improvements and Practical Expedients” May 2014 and subsequent These standards outline a single comprehensive model for entities to use in accounting for revenue using a five-step process that supersedes virtually all existing revenue guidance. The underlying principle is that an entity should recognize revenue to depict the transfer of 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. Entities have the option of using either a full retrospective approach or a modified retrospective approach to adopt the guidance. Early adoption is permitted. December 31, 2017 On December 31, 2017, we adopted the new accounting standard ASC 606, “Revenue from Contracts with Customers” using the modified retrospective method. We recognized the cumulative effect as an adjustment to our opening balance of retained earnings. Effective December 31, 2017, we adopted the requirements of Topic 606. The cumulative effects of the changes made to our statement of income and balance sheet were as follows: For the Period ended March 24, 2018 As Reported Balances Without Adoption of Topic 606 Effect of Change (thousands) Higher/(Lower) Statement of Income Service revenues $ 54,137 $ 54,106 $ 31 Total revenues 83,147 83,116 31 Operating (loss) income (293 ) (324 ) 31 (Loss) income before income taxes (538 ) (569 ) 31 (Benefit from) provision for income taxes (436 ) (461 ) 25 Net (loss) income (102 ) (108 ) 6 Net (loss) income attributable to Heritage-Crystal Clean, Inc. common stockholders $ (120 ) $ (126 ) $ 6 March 24, 2018 As Reported Balances Without Adoption of Topic 606 Effect of Change (thousands) Higher/(Lower) Balance Sheet Contract liabilities - net $ 237 $ — $ 237 Total Current Liabilities 41,081 40,844 237 Deferred income taxes 9,170 9,145 25 Total Liabilities 79,065 78,803 262 Retained earnings 40,971 41,233 (262 ) Total Heritage-Crystal Clean, Inc. Stockholders' Equity 234,737 234,999 (262 ) Total Equity $ 235,453 $ 235,715 $ (262 )

Revenue

Revenue	3 Months Ended
	Mar. 24, 2018
Revenue from Contract with Customer [Abstract]
Revenue	REVENUE We account for a contract when it has approval and commitment from both parties, the rights of the parties are identified, payment terms are identified, the contract has commercial substance and collectability of consideration is probable. Revenue is recognized when our performance obligations under the terms of a contract with our customers are satisfied. Recognition occurs when the Company transfers control by completing the specified services at the point in time the customer benefits from the services performed or once our products are delivered. Revenue is measured as the amount of consideration we expect to receive in exchange for completing our performance obligations. Sales tax and other taxes we collect with revenue-producing activities are excluded from revenue. In the case of contracts with multiple performance obligations, the Company allocates the transaction price to each performance obligation based on the relative stand-alone selling prices of the various goods and/or services encompassed by the contract. We do not have any material significant payment terms as payment is generally due within 30 days after the performance obligation has been satisfactorily completed. The Company has elected the practical expedient to recognize the incremental costs of obtaining a contract as an expense when incurred if the amortization period of the asset that we otherwise would have recognized is one year or less. In applying the guidance in Topic 606, there were no judgments or estimates made that the Company deems significant. Accounts Receivable — Net, includes amounts billed and currently due from customers. The amounts due are stated at their net estimated realizable value. The allowance for doubtful accounts is the Company's best estimate of the amount of probable credit losses in the Company's existing accounts receivable. The Company determines the allowance based on analysis of customer credit worthiness and historical losses. Accounts receivable are written off once the Company determines the account to be uncollectible. The Company does not have any off-balance-sheet credit exposure related to its customers. Contract Balances — Contract assets primarily relate to the Company’s rights to consideration for work completed in relation to its services performed but not billed at the reporting date. Contract liabilities primarily consist of advance payments of performance obligations yet to be fully satisfied in the period reported. Our contract liabilities and contract assets are reported in a net position at the end of each reporting period. We disaggregate our revenue from contracts with customers by major lines of business for each of our segments, as we believe it best depicts how the nature, amount, timing and uncertainty of our revenue and cash flows are affected by economic factors. The following table disaggregates our revenue by major lines: For the first quarter ended March 24, 2018 Total Net Sales by Major Lines of Business (thousands) Environmental Services Oil Business Total Parts cleaning, containerized waste, & related products/services $ 39,615 $ — $ 39,615 Vacuum Services & Wastewater Treatment 11,847 — 11,847 Antifreeze Business 3,459 — 3,459 Field Services 2,155 — 2,155 Environmental Services - Other 400 — 400 Re-refinery Product Sales — 20,485 20,485 Oil Collection Services & RFO — 4,017 4,017 Oil Filter Business — 1,077 1,077 Revenues from Contracts with Customers 57,476 25,579 83,055 Other Revenue — 92 92 Total Revenues $ 57,476 $ 25,671 $ 83,147 The following table provides information about contract assets and contract liabilities from contracts with customers: (thousands) March 24, 2018 December 31, 2017 Contract assets $ 44 $ 59 Contract liabilities 281 327 Contract liabilities - net $ 237 $ 268 During the quarter ended March 24, 2018, the Company recognized $31 thousand of revenue that was included in the contract liabilities balance as of December 31, 2017. The Company had no assets recognized from costs to obtain or fulfill a contract with a customer. We do not disclose the value of unsatisfied performance obligations for contracts with an original expected length of one year or less.

Accounts Receivable

Accounts Receivable	3 Months Ended
	Mar. 24, 2018
Accounts Receivable, Net [Abstract]
Accounts Receivable	ACCOUNTS RECEIVABLE Accounts receivable consisted of the following: (Thousands) March 24, December 30, Trade $ 44,072 $ 43,301 Less: allowance for doubtful accounts (1,923 ) (1,881 ) Trade - net 42,149 41,420 Related parties 2,042 1,906 Other 2,692 2,165 Total accounts receivable - net $ 46,883 $ 45,491 The following table provides the changes in the Company’s allowance for doubtful accounts for the first quarter ended March 24, 2018 , and the fiscal year ended December 30, 2017 : For the Quarter Ended, For the Fiscal Year Ended, (Thousands) March 24, December 30, Balance at beginning of period $ 1,881 $ 2,176 Provision for bad debts 286 402 Accounts written off, net of recoveries (244 ) (697 ) Balance at end of period $ 1,923 $ 1,881

Inventory

Inventory	3 Months Ended
	Mar. 24, 2018
Inventory Disclosure [Abstract]
Inventory	INVENTORY The carrying value of inventory consisted of the following: (Thousands) March 24, December 30, Used oil and processed oil $ 8,062 $ 5,788 Solvents and solutions 6,820 6,201 Drums and supplies 4,785 4,430 Machines 3,862 3,679 Other 2,146 1,936 Total inventory 25,675 22,034 Less: machine refurbishing reserve (281 ) (395 ) Total inventory - net $ 25,394 $ 21,639 Inventory consists primarily of used oil, processed oil, solvents and solutions, new and refurbished parts cleaning machines, drums and supplies, and other items. Inventories are valued at the lower of first-in, first-out (FIFO) cost or net realizable value, net of any reserves for excess, obsolete, or unsalable inventory. The Company routinely monitors its inventory levels at each of its locations and evaluates inventories for excess or slow-moving items. If circumstances indicate the cost of inventories exceed their recoverable value, inventories are reduced to net realizable value. The Company had no inventory write downs during the first quarters of fiscal 2018 and fiscal 2017.

Property, Plant, and Equipment

Property, Plant, and Equipment	3 Months Ended
	Mar. 24, 2018
Property, Plant and Equipment [Abstract]
Property, Plant, and Equipment	PROPERTY, PLANT, AND EQUIPMENT Property, plant, and equipment consisted of the following: (Thousands) March 24, December 30, Machinery, vehicles, and equipment $ 85,683 $ 85,427 Buildings and storage tanks 69,055 69,009 Land 9,557 9,562 Leasehold improvements 5,468 5,427 Construction in progress 11,280 9,378 Assets held for sale 53 53 Total property, plant and equipment 181,096 178,856 Less: accumulated depreciation (52,592 ) (50,737 ) Property, plant and equipment - net $ 128,504 $ 128,119 (Thousands) March 24, December 30, Equipment at customers $ 69,388 $ 68,234 Less: accumulated depreciation (45,915 ) (44,922 ) Equipment at customers - net $ 23,473 $ 23,312 Depreciation expense for first quarters ended March 24, 2018 and March 25, 2017 was $2.9 million and $3.4 million , respectively.

Goodwill and Other Intangible A

Goodwill and Other Intangible Assets	3 Months Ended
	Mar. 24, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Other Intangible Assets	GOODWILL AND OTHER INTANGIBLE ASSETS Goodwill is measured as a residual amount as of the acquisition date, which in most cases results in measuring goodwill as an excess of the purchase consideration transferred plus the fair value of any noncontrolling interest in the acquiree over the fair value of the net assets acquired, including any contingent consideration. The Company tests goodwill for impairment annually in the fourth quarter and in interim periods if an event occurs or circumstances change that would more likely than not reduce the fair value of a reporting unit below its carrying amount. The Company's determination of fair value requires certain assumptions and estimates, such as margin expectations, market conditions, growth expectations, expected changes in working capital, etc., regarding expected future profitability and expected future cash flows. The Company tests goodwill for impairment at each of its two reporting units, Environmental Services and Oil Business. The following table shows changes to our goodwill balances by segment from December 30, 2017, to March 24, 2018: (Thousands) Oil Business Environmental Services Total Goodwill at December 30, 2017 Gross carrying amount $ 3,952 $ 31,580 $ 35,532 Accumulated impairment loss (3,952 ) — (3,952 ) Net book value at December 30, 2017 $ — $ 31,580 $ 31,580 Measurement period adjustments — — — Goodwill at March 24, 2018 Gross carrying amount 3,952 31,580 35,532 Accumulated impairment loss (3,952 ) — (3,952 ) Net book value at March 24, 2018 $ — $ 31,580 $ 31,580 The following is a summary of software and other intangible assets: March 24, 2018 December 30, 2017 (Thousands) Gross Carrying Amount Accumulated Amortization Net Carrying Amount Gross Carrying Amount Accumulated Amortization Net Carrying Amount Customer & supplier relationships $ 23,071 $ 9,565 $ 13,506 $ 23,077 $ 9,027 $ 14,050 Software 4,724 3,954 770 4,724 3,899 825 Non-compete agreements 2,945 2,705 240 2,949 2,617 332 Patents, formulae, and licenses 1,769 657 1,112 1,769 642 1,127 Other 1,348 971 377 1,348 950 398 Total software and intangible assets $ 33,857 $ 17,852 $ 16,005 $ 33,867 $ 17,135 $ 16,732 Amortization expense was $0.7 million for the first quarter ended March 24, 2018 , and $0.8 million for first quarter ended March 25, 2017 . The weighted average useful lives of software; customer & supplier relationships; patents, formulae, and licenses; non-compete agreements, and other intangibles were 9 years, 10 years, 15 years, 5 years, and 6 years, respectively. The expected amortization expense for the remainder of fiscal 2018 and for fiscal years 2019, 2020, 2021, and 2022 is $2.3 million , $2.6 million , $2.5 million , $2.4 million , and $2.1 million , respectively. The preceding expected amortization expense is an estimate. Actual amounts of amortization expense may differ from estimated amounts due to additional intangible asset acquisitions, disposal of intangible assets, accelerated amortization of intangible assets, and other events.

Accounts Payable

Accounts Payable	3 Months Ended
	Mar. 24, 2018
Payables and Accruals [Abstract]
Accounts Payable	ACCOUNTS PAYABLE Accounts payable consisted of the following: (Thousands) March 24, December 30, Accounts payable $ 27,488 $ 25,540 Accounts payable - related parties 361 28 Total accounts payable $ 27,849 $ 25,568

Debt and Financing Arrangements

Debt and Financing Arrangements	3 Months Ended
	Mar. 24, 2018
Debt Disclosure [Abstract]
Debt and Financing Arrangements	DEBT AND FINANCING ARRANGEMENTS Bank Credit Facility The Company's Credit Agreement as amended ("Credit Agreement"), provides for borrowings of up to $95.0 million , subject to the satisfaction of certain terms and conditions, comprised of a term loan of $30.0 million and up to $65.0 million of borrowings under the revolving loan portion. The actual amount of borrowings available under the revolving loan portion of the Credit Agreement is limited by the Company's total leverage ratio. The amount available to draw at any point in time would be further reduced by any standby letters of credit issued. Loans made under the Credit Agreement may be Base Rate Loans or LIBOR Rate Loans, at the election of the Company subject to certain exceptions. Base Rate Loans have an interest rate equal to (i) the higher of (a) the federal funds rate plus 0.5% , (b) the London Interbank Offering Rate (“LIBOR”) plus 1% , or (c) Bank of America's prime rate, plus (ii) a variable margin of between 0.75% and 1.75% depending on the Company's total leverage ratio, calculated on a consolidated basis. LIBOR rate loans have an interest rate equal to (i) the LIBOR rate plus (ii) a variable margin of between 1.75% and 2.75% depending on the Company's total leverage ratio. Amounts borrowed under the Credit Agreement are secured by a security interest in substantially all of the Company's tangible and intangible assets. The Credit Agreement contains customary terms and provisions (including representations, covenants, and conditions) for transactions of this type. Certain covenants, among other things, restrict the Company's and its subsidiaries' ability to incur indebtedness, grant liens, make investments and sell assets. The Credit Agreement also contains customary events of default, covenants and representations and warranties. Financial covenants include: • An interest coverage ratio (based on interest expense and EBITDA) of at least 3.5 to 1.0 ; • A total leverage ratio no greater than 3.0 to 1.0 , provided that in the event of a permitted acquisition having an aggregate consideration equal to $10.0 million or more, at the Borrower’s election, the foregoing 3.00 to 1.00 shall be deemed to be 3.25 to 1.00 for the fiscal quarter in which such permitted acquisition occurs and the three immediately following fiscal quarters and will thereafter revert to 3.00 to 1.00 ; and • A capital expenditures covenant limiting capital expenditures to $100.0 million plus, if the capital expenditures permitted have been fully utilized, an additional amount for the remaining term of the Credit Agreement equal to 35% of EBITDA for the thirteen “four-week” periods most recently ended immediately prior to the full utilization of such $100.0 million basket. The Credit Agreement places certain limitations on acquisitions and the payment of dividends. During the first quarter of fiscal 2017, the Company paid and capitalized $1.1 million of debt issuance costs pertaining to the Credit Agreement and charged $0.2 million of unamortized debt issuance costs pertaining to the Credit Agreement to selling, general, and administrative expenses. Debt at March 24, 2018 and December 30, 2017 consisted of the following: (thousands) March 24, 2018 December 30, 2017 Principal amount $ 30,000 $ 30,000 Less: unamortized debt issuance costs 1,186 1,256 Debt less unamortized debt issuance costs $ 28,814 $ 28,744 During the first quarter of fiscal 2018 , the Company recorded interest of $0.3 million on the term loan. During the first quarter of fiscal 2017, the Company recorded interest of $0.5 million on the term loan. In the first quarter of 2018, the Company also recorded $0.1 million of amortization of debt issuance costs. No interest was capitalized during the first quarters of fiscal 2018 or 2017. The Company's weighted average interest rate for all debt as of March 24, 2018 , and March 25, 2017 was 3.4% and 3.5% , respectively. As of March 24, 2018 and December 30, 2017 , the Company was in compliance with all covenants under its Credit Agreement. As of March 24, 2018 and December 30, 2017 , the Company had $1.2 million and $0.9 million of standby letters of credit issued, respectively, and $63.8 million and $64.1 million was available for borrowing under the bank credit facility, respectively. We believe that the carrying value of our debt balance at March 24, 2018 approximates fair value.

Segment Information

Segment Information	3 Months Ended
	Mar. 24, 2018
Segment Reporting [Abstract]
Segment Information	SEGMENT INFORMATION The Company has two reportable segments: "Environmental Services" and "Oil Business." The Environmental Services segment consists of the Company's parts cleaning, containerized waste management, vacuum truck service, antifreeze recycling activities, and field services. The Oil Business segment consists primarily of the Company's used oil collection, used oil re-refining activities, and the dehydration of used oil to be sold as recycled fuel oil. No single customer in either segment accounted for more than 10.0% of consolidated revenues in any of the periods presented. There were no intersegment revenues. The Environmental Services segment operates in the United States and, to an immaterial degree, in Ontario, Canada. As such, the Company is not disclosing operating results by geographic segment. Segment results for the first quarters ended March 24, 2018 , and March 25, 2017 were as follows: First Quarter Ended, March 24, 2018 (Thousands) Environmental Services Oil Business Corporate and Consolidated Revenues Product revenues $ 6,444 $ 22,566 $ — $ 29,010 Service revenues 51,032 3,105 — 54,137 Total revenues $ 57,476 $ 25,671 $ — $ 83,147 Operating expenses Operating costs 42,725 25,661 — 68,386 Operating depreciation and amortization 1,490 1,389 — 2,879 Profit (loss) before corporate selling, general, and administrative expenses $ 13,261 $ (1,379 ) $ — $ 11,882 Selling, general, and administrative expenses 11,022 11,022 Depreciation and amortization from SG&A 764 764 Total selling, general, and administrative expenses $ 11,786 $ 11,786 Other expense - net 389 389 Operating (loss) (293) Interest expense – net 245 245 (Loss) before income taxes $ (538 ) First Quarter Ended, March 25, 2017 (Thousands) Environmental Services Oil Business Corporate and Consolidated Revenues Product revenues $ 5,724 $ 21,256 $ — $ 26,980 Service revenues 47,492 5,981 — 53,473 Total revenues $ 53,216 $ 27,237 $ — $ 80,453 Operating expenses Operating costs 36,520 24,770 — 61,290 Operating depreciation and amortization 1,746 1,535 — 3,281 Profit before corporate selling, general, and administrative expenses $ 14,950 $ 932 $ — $ 15,882 Selling, general, and administrative expenses 12,341 12,341 Depreciation and amortization from SG&A 851 851 Total selling, general, and administrative expenses $ 13,192 $ 13,192 Other (income) - net (5,006) (5,006) Operating income 7,696 Interest expense – net 87 87 Income before income taxes $ 7,609 Total assets by segment as of March 24, 2018 and December 30, 2017 were as follows: (Thousands) March 24, 2018 December 30, 2017 Total Assets: Environmental Services $ 133,881 $ 131,457 Oil Business 132,652 129,936 Unallocated Corporate Assets 47,985 53,264 Total $ 314,518 $ 314,657 Segment assets for the Environmental Services and Oil Business segments consist of property, plant, and equipment, intangible assets, accounts receivable, goodwill, and inventories. Assets for the corporate unallocated amounts consist of property, plant, and equipment used at the corporate headquarters as well as cash and net deferred tax assets.

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 24, 2018
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	COMMITMENTS AND CONTINGENCIES The Company may enter into purchase obligations with certain vendors. They represent expected payments to third party service providers and other commitments entered into during the normal course of our business. These purchase obligations are generally cancelable with or without notice, without penalty, although certain vendor agreements provide for cancellation fees or penalties depending on the terms of the contract. The Company has purchase obligations in the form of open purchase orders of $16.3 million as of March 24, 2018 , and $15.6 million as of December 30, 2017, primarily for used oil, solvent, machine purchases, disposal and transportation expenses, and capital expenditures. The Company may be subject to investigations, claims or lawsuits as a result of operating its business, including matters governed by environmental laws and regulations. The Company may also be subject to tax audits in a variety of jurisdictions. When claims are asserted, the Company evaluates the likelihood that a loss will occur and records a liability for those instances when the likelihood is deemed probable and the exposure is reasonably estimable. The Company carries insurance at levels it believes are adequate to cover loss contingencies based on historical claims activity. When the potential loss exposure is limited to the insurance deductible and the likelihood of loss is determined to be probable, the Company accrues for the amount of the required deductible, unless a lower amount of exposure is estimated. As of March 24, 2018 and December 30, 2017 , the Company had accrued $4.0 million and $4.5 million related to loss contingencies and other contingent liabilities, respectively.

Income Taxes

Income Taxes	3 Months Ended
	Mar. 24, 2018
Income Tax Disclosure [Abstract]
Income Taxes	INCOME TAXES On December 22, 2017, the Tax Cuts and Jobs Act (the "Act") was enacted into law and introduced significant changes to U.S. tax law. The Act reduces the U.S. federal corporate tax rate from 35% to 21% . The new legislation also sets forth a variety of other changes, including a limitation on the tax deductibility of interest expense, the acceleration of business asset expensing, a limitation on the use of net operating losses generated in future years, the repeal of the alternative minimum tax (AMT), and a reduction in the amount of executive pay that could qualify as a tax deduction. Due to the timing and the complexity involved in applying the provisions of the Act, the Company did not record provisional amounts in our financial statements as of December 30, 2017 related to the one time deemed repatriation of foreign earnings. As the Company collects and prepares necessary data, and interprets the Act and any additional guidance issued by the U.S. Treasury Department, the Internal Revenue Service (IRS), and other standard-setting bodies, the Company will record the provisional amounts related to the one time deemed repatriation of its Canadian subsidiary’s accumulated foreign earnings. The accounting for the tax effects of the deemed repatriation of foreign earnings will be completed later in 2018. The Company estimates that the income related to the deemed repatriation will be offset by U.S. net operating losses. The Company deducted for federal income tax purposes accelerated "bonus" depreciation on the majority of its capital expenditures for assets placed in service in fiscal 2011 through fiscal 2017. Therefore, the Company recorded a deferred tax liability related to the difference between the book basis and the tax basis of those assets. In addition, as a result of the federal bonus depreciation, the Company recorded a Net Operating Loss ("NOL") of $44.7 million , which will begin to expire in 2031. The unexpired balance of the NOL generated in 2011 is $13.7 million as of March 24, 2018. The Company recorded additional NOL during 2012 - 2015 of $13.0 million . The balance on the federal NOL’s generated from 2011 through 2015 at March 24, 2018 was $26.7 million , and the remaining deferred tax asset related to the Company's state and federal NOL was a tax effected balance of $6.3 million . ASU 2016-09 simplified the treatment for employee share-based compensation by allowing an entity to recognize excess tax benefits in the current period whether or not current taxes payable are reduced. Prior to 2017 the Company could not recognize windfall tax benefits associated with employee share-based compensation because it was in an NOL position and current taxes payable would not be reduced by the excess tax benefits. As a result of ASU 2016-09 the Company recognized excess tax benefits of $2.5 million from share-based compensation from prior years, resulting in cumulative-effect increases to retained earnings and deferred tax assets of approximately $1.0 million . The Company's effective tax rate for the first quarter of fiscal 2018 was 81.1% compared to 36.7% in the first quarter of fiscal 2017 . The rate difference is principally attributable to the differing treatment for financial reporting and income tax reporting of equity compensation. The Company establishes reserves when it is more likely than not that the Company will not realize the full tax benefit of a position. The Company had a reserve of $2.4 million for uncertain tax positions as of March 24, 2018 and December 30, 2017 . The gross unrecognized tax benefits would, if recognized, decrease the Company's effective tax rate.

Share-based Compensation

Share-based Compensation	3 Months Ended
	Mar. 24, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Share-based Compensation	SHARE-BASED COMPENSATION The aggregate number of shares of common stock which may be issued under the Company’s 2008 Omnibus Plan ("Plan") is 2,602,077 plus any common stock that becomes available for issuance pursuant to the reusage provision of the Plan. As of March 24, 2018 , the number of shares available for issuance under the Plan was 536,953 shares. Stock Option Awards A summary of stock option activity under this Plan is as follows: Outstanding Stock Options Number of Options Outstanding Weighted Average Exercise Price Weighted Average Remaining Contractual Term (in years) Aggregate Intrinsic Value as of Date Listed (in thousands) Options outstanding at December 30, 2017 19,435 $ 7.33 1.23 $ 280 Exercised — — — — Options outstanding at March 24, 2018 19,435 $ 7.33 1.00 $ 301 Restricted Stock Compensation/Awards Annually, the Company grants restricted shares to its Board of Directors. The shares become fully vested one year from their grant date. The fair value of each restricted stock grant is based on the closing price of the Company's common stock on the date of grant. The Company amortizes the expense over the service period, which is the fiscal year in which the award is granted. In addition, the Company may grant restricted shares to certain members of management based on their services and contingent upon continued service with the Company. The restricted shares vest over a period of approximately three years from the grant date. The fair value of each restricted stock grant is based on the closing price of the Company's common stock on the date of grant. The following table shows a summary of restricted share grants and expense resulting from the awards: Compensation Expense (thousands, except for shares total) First Quarter Ended, Unrecognized Expense as of, Recipient of Grant Grant Date Restricted Shares March 24, 2018 March 25, 2017 March 24, 2018 December 30, 2017 Board of Directors April, 2017 14,980 $ 66 $ 66 $ — $ — Members of Management January, 2016 43,208 21 24 80 101 Members of Management February, 2017 146,564 99 93 742 841 Members of Management February, 2018 116,958 122 285 1,648 1,770 Chief Executive Officer February, 2017 500,000 511 174 1,912 2,423 In February 2017, as part of Mr. Recatto's employment agreement, the Company granted a restricted stock award of 500,000 shares of common stock, which vests through January 2021 in an amount based on the vesting table below, with the common stock price increase to be determined based on the increase in the price of the Company’s common stock (if any) from the closing price of the common stock as reported by Nasdaq on the employment commencement date ( $15.00 ) and the common stock price on the potential vesting date (determined by using the weighted average closing price of a share of the Company's common stock for the 90-day period ending on the vesting date). If the stock price does not increase by $5.00 , then no shares shall vest. During the first quarter of fiscal 2018, the Company recorded approximately $0.5 million of compensation expense, which includes $ 0.2 million of expense from the recognition of an accelerated vesting, related to this award. In the future, the Company expects to recognize compensation expense of approximately $1.9 million over the remaining requisite service period, which ends January 31, 2021. The fair value of this restricted stock award as of the grant date was estimated using a Monte Carlo simulation model. Key assumptions used in the Monte Carlo simulation to estimate the grant date fair value of this award are a risk-free rate of 1.70% , expected dividend yield of zero , and an expected volatility assumption of 41.73% . Vesting Table Increase in Stock Price From the Employment Commencement Date to the Vesting Date Total percentage of Restricted Stock Shares to Be Vested Less than $5 per share increase —% $5 per share increase 25% $10 per share increase 50% $15 per share increase 75% $20 or more per share increase 100% Provision for possible accelerated vesting of award If the average closing price of the Company's common stock increases by the marginal levels set forth in the above vesting table for any consecutive 180 day period between the award date and final vesting date, Mr. Recatto shall become vested in 50% of the corresponding total percentage of restricted shares earned on the last day of the 180 day period. On March 14, 2018, the weighted average closing price of the Company's common stock met the 25% marginal level and Mr. Recatto became fully vested in half of the 125,000 vested shares. The following table summarizes the restricted stock activity for the period ended March 24, 2018 : Restricted Stock (Nonvested Shares) Number of Shares Weighted Average Grant-Date Fair Value Per Share Nonvested shares outstanding at December 30, 2017 685,999 $ 14.52 Granted 116,957 20.35 Vested (134,730 ) 14.42 Nonvested shares outstanding at March 24, 2018 668,226 $ 15.92 Employee Stock Purchase Plan As of March 24, 2018 , the Company had reserved 145,204 shares of common stock available for purchase under the Employee Stock Purchase Plan of 2008 . In the first quarter of fiscal 2018 , employees purchased 4,822 shares of the Company’s common stock with a weighted average fair market value of $21.90 per share.

Earnings Per Share

Earnings Per Share	3 Months Ended
	Mar. 24, 2018
Earnings Per Share [Abstract]
Earnings Per Share	EARNINGS PER SHARE The following table reconciles the number of shares outstanding for the first quarters of fiscal 2018 and 2017 , respectively, to the number of weighted average basic shares outstanding and the number of weighted average diluted shares outstanding for the purposes of calculating basic and diluted earnings per share: First Quarter Ended, (Thousands) March 24, 2018 March 25, 2017 Net (loss) income $ (102 ) $ 4,817 Less: Income attributable to noncontrolling interest 18 53 Net (loss) income attributable to Heritage-Crystal Clean, Inc. available to common stockholders $ (120 ) $ 4,764 Weighted average basic shares outstanding 22,962 22,353 Dilutive shares from share–based compensation plans — 539 Weighted average diluted shares outstanding 22,962 22,892 Number of anti–dilutive potentially issuable shares excluded from diluted shares outstanding 170 — Net (loss) income per share: basic $ (0.01 ) $ 0.21 Net (loss) income per share: diluted $ (0.01 ) $ 0.21

Other Expense (Income) - Net

Other Expense (Income) - Net	3 Months Ended
	Mar. 24, 2018
Other Income and Expenses [Abstract]
Other Expense (Income) - Net	OTHER EXPENSE (INCOME) - NET Other expense (income) of $0.4 million for the first quarter of fiscal 2018 primarily represents $0.3 million of site closure costs for a facility in Wilmington, DE. Other expense (income) for the first quarter of fiscal 2017 included a gain of $5.1 million as a result of having received a partial award for a claim made in arbitration related to our acquisition of FCC Environmental, LLC and International Petroleum Corp. of Delaware in 2014.

Subsequent Events

Subsequent Events	3 Months Ended
	Mar. 24, 2018
Subsequent Events [Abstract]
Subsequent Events	SUBSEQUENT EVENTS Pursuant to the Heritage-Crystal Clean, Inc. Omnibus Incentive Plan of 2008, on April 13, 2018, the Company granted 350,000 shares of restricted stock to certain members of Management as part of a Special Incentive Program. The number of shares granted may be increased up to 612,500 shares depending on the Company’s level of performance with regard to certain market conditions. Between zero and 612,500 shares will vest on April 13, 2022, depending on the satisfaction of certain service and market conditions. On May 3, 2018, the Company purchased the assets of Products Plus, Inc. and AO Holding-Kansas City, LLC (collectively "PPI") pursuant to an Asset Purchase Agreement. The Company purchased the assets of PPI to expand the Company’s market share in the collection, recycling, and sales of a full line of antifreeze products. The purchase price was set at $5.9 million subject to certain adjustments, including a working capital adjustment and a contingent consideration provision. The Company initially paid $4.2 million of cash at closing. The results of PPI will be consolidated into the Company’s Environmental Services segment.

Summary of Significant Accoun23

Summary of Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 24, 2018
Accounting Policies [Abstract]
Fiscal Period	The Company’s fiscal year ends on the Saturday closest to December 31. The most recent fiscal year ended on December 30, 2017 . Each of the Company's first three fiscal quarters consists of twelve weeks while the last fiscal quarter consists of sixteen or seventeen weeks.
Recently Issued Accounting Pronouncements	Recently Issued Accounting Pronouncements Standard Issuance Date Description Our Effective Date Effect on the Financial Statements ASU 2016-02 February 2016 This update was issued to increase transparency and comparability among organizations by recognizing lease assets and lease liabilities on the balance sheet and disclosing key information about leasing arrangements. Early application of the amendments in this update is permitted for all entities. January 4, 2019 The Company is currently evaluating the effect that implementation of this update will have on its consolidated financial position and results of operations. The Company anticipates that implementation of this standard will result in an increase to assets and an increase to liabilities. To date, certain personnel have attended technical training concerning this new lease accounting standard. Recently Issued Accounting Standards Adopted Standard Issuance Date Description Effective Date Effect on the Financial Statements ASU 2014-09 “Revenue from Contracts with Customers (Topic 606),” ASU 2014-15 “Revenue from Contracts with Customers (Topic 606): Deferral of the Effective Date,” ASU 2016-08 “Revenue from Contracts with Customers (Topic 606): Principal versus Agent Considerations (Reporting Revenue Gross versus Net),” ASU 2016-10 “ Revenue from Contracts with Customers (Topic 606): Identifying Performance Obligations and Licensing,” and ASU 2016-12 “Revenue from Contracts with Customers (Topic 606): Narrow-Scope Improvements and Practical Expedients” May 2014 and subsequent These standards outline a single comprehensive model for entities to use in accounting for revenue using a five-step process that supersedes virtually all existing revenue guidance. The underlying principle is that an entity should recognize revenue to depict the transfer of 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. Entities have the option of using either a full retrospective approach or a modified retrospective approach to adopt the guidance. Early adoption is permitted. December 31, 2017 On December 31, 2017, we adopted the new accounting standard ASC 606, “Revenue from Contracts with Customers” using the modified retrospective method. We recognized the cumulative effect as an adjustment to our opening balance of retained earnings.

Summary of Significant Accoun24

Summary of Significant Accounting Policies (Tables)	3 Months Ended
	Mar. 24, 2018
Accounting Policies [Abstract]
Schedule of Recently Issued Accounting Pronouncements	Effective December 31, 2017, we adopted the requirements of Topic 606. The cumulative effects of the changes made to our statement of income and balance sheet were as follows: For the Period ended March 24, 2018 As Reported Balances Without Adoption of Topic 606 Effect of Change (thousands) Higher/(Lower) Statement of Income Service revenues $ 54,137 $ 54,106 $ 31 Total revenues 83,147 83,116 31 Operating (loss) income (293 ) (324 ) 31 (Loss) income before income taxes (538 ) (569 ) 31 (Benefit from) provision for income taxes (436 ) (461 ) 25 Net (loss) income (102 ) (108 ) 6 Net (loss) income attributable to Heritage-Crystal Clean, Inc. common stockholders $ (120 ) $ (126 ) $ 6 March 24, 2018 As Reported Balances Without Adoption of Topic 606 Effect of Change (thousands) Higher/(Lower) Balance Sheet Contract liabilities - net $ 237 $ — $ 237 Total Current Liabilities 41,081 40,844 237 Deferred income taxes 9,170 9,145 25 Total Liabilities 79,065 78,803 262 Retained earnings 40,971 41,233 (262 ) Total Heritage-Crystal Clean, Inc. Stockholders' Equity 234,737 234,999 (262 ) Total Equity $ 235,453 $ 235,715 $ (262 )

Revenue (Tables)

Revenue (Tables)	3 Months Ended
	Mar. 24, 2018
Revenue from Contract with Customer [Abstract]
Schedule of Disaggregation of Revenue by Major Lines	The following table disaggregates our revenue by major lines: For the first quarter ended March 24, 2018 Total Net Sales by Major Lines of Business (thousands) Environmental Services Oil Business Total Parts cleaning, containerized waste, & related products/services $ 39,615 $ — $ 39,615 Vacuum Services & Wastewater Treatment 11,847 — 11,847 Antifreeze Business 3,459 — 3,459 Field Services 2,155 — 2,155 Environmental Services - Other 400 — 400 Re-refinery Product Sales — 20,485 20,485 Oil Collection Services & RFO — 4,017 4,017 Oil Filter Business — 1,077 1,077 Revenues from Contracts with Customers 57,476 25,579 83,055 Other Revenue — 92 92 Total Revenues $ 57,476 $ 25,671 $ 83,147
Contract Assets and Contract Liabilities from Contracts with Customers	The following table provides information about contract assets and contract liabilities from contracts with customers: (thousands) March 24, 2018 December 31, 2017 Contract assets $ 44 $ 59 Contract liabilities 281 327 Contract liabilities - net $ 237 $ 268

Accounts Receivable (Tables)

Accounts Receivable (Tables)	3 Months Ended
	Mar. 24, 2018
Accounts Receivable, Net [Abstract]
Schedule of Accounts Receivable and Allowance for Doubtful Accounts	Accounts receivable consisted of the following: (Thousands) March 24, December 30, Trade $ 44,072 $ 43,301 Less: allowance for doubtful accounts (1,923 ) (1,881 ) Trade - net 42,149 41,420 Related parties 2,042 1,906 Other 2,692 2,165 Total accounts receivable - net $ 46,883 $ 45,491 The following table provides the changes in the Company’s allowance for doubtful accounts for the first quarter ended March 24, 2018 , and the fiscal year ended December 30, 2017 : For the Quarter Ended, For the Fiscal Year Ended, (Thousands) March 24, December 30, Balance at beginning of period $ 1,881 $ 2,176 Provision for bad debts 286 402 Accounts written off, net of recoveries (244 ) (697 ) Balance at end of period $ 1,923 $ 1,881

Inventory (Tables)

Inventory (Tables)	3 Months Ended
	Mar. 24, 2018
Inventory Disclosure [Abstract]
Schedule of Inventory	The carrying value of inventory consisted of the following: (Thousands) March 24, December 30, Used oil and processed oil $ 8,062 $ 5,788 Solvents and solutions 6,820 6,201 Drums and supplies 4,785 4,430 Machines 3,862 3,679 Other 2,146 1,936 Total inventory 25,675 22,034 Less: machine refurbishing reserve (281 ) (395 ) Total inventory - net $ 25,394 $ 21,639

Property, Plant, and Equipment

Property, Plant, and Equipment (Tables)	3 Months Ended
	Mar. 24, 2018
Property, Plant and Equipment [Abstract]
Summary of Property, Plant, and Equipment	Property, plant, and equipment consisted of the following: (Thousands) March 24, December 30, Machinery, vehicles, and equipment $ 85,683 $ 85,427 Buildings and storage tanks 69,055 69,009 Land 9,557 9,562 Leasehold improvements 5,468 5,427 Construction in progress 11,280 9,378 Assets held for sale 53 53 Total property, plant and equipment 181,096 178,856 Less: accumulated depreciation (52,592 ) (50,737 ) Property, plant and equipment - net $ 128,504 $ 128,119 (Thousands) March 24, December 30, Equipment at customers $ 69,388 $ 68,234 Less: accumulated depreciation (45,915 ) (44,922 ) Equipment at customers - net $ 23,473 $ 23,312

Goodwill and Other Intangible29

Goodwill and Other Intangible Assets (Tables)	3 Months Ended
	Mar. 24, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Goodwill	The following table shows changes to our goodwill balances by segment from December 30, 2017, to March 24, 2018: (Thousands) Oil Business Environmental Services Total Goodwill at December 30, 2017 Gross carrying amount $ 3,952 $ 31,580 $ 35,532 Accumulated impairment loss (3,952 ) — (3,952 ) Net book value at December 30, 2017 $ — $ 31,580 $ 31,580 Measurement period adjustments — — — Goodwill at March 24, 2018 Gross carrying amount 3,952 31,580 35,532 Accumulated impairment loss (3,952 ) — (3,952 ) Net book value at March 24, 2018 $ — $ 31,580 $ 31,580
Schedule of Intangible Assets	The following is a summary of software and other intangible assets: March 24, 2018 December 30, 2017 (Thousands) Gross Carrying Amount Accumulated Amortization Net Carrying Amount Gross Carrying Amount Accumulated Amortization Net Carrying Amount Customer & supplier relationships $ 23,071 $ 9,565 $ 13,506 $ 23,077 $ 9,027 $ 14,050 Software 4,724 3,954 770 4,724 3,899 825 Non-compete agreements 2,945 2,705 240 2,949 2,617 332 Patents, formulae, and licenses 1,769 657 1,112 1,769 642 1,127 Other 1,348 971 377 1,348 950 398 Total software and intangible assets $ 33,857 $ 17,852 $ 16,005 $ 33,867 $ 17,135 $ 16,732

Accounts Payable (Tables)

Accounts Payable (Tables)	3 Months Ended
	Mar. 24, 2018
Payables and Accruals [Abstract]
Schedule of Accounts Payable	Accounts payable consisted of the following: (Thousands) March 24, December 30, Accounts payable $ 27,488 $ 25,540 Accounts payable - related parties 361 28 Total accounts payable $ 27,849 $ 25,568

Debt and Financing Arrangemen31

Debt and Financing Arrangements (Tables)	3 Months Ended
	Mar. 24, 2018
Debt Disclosure [Abstract]
Schedule of Debt	Debt at March 24, 2018 and December 30, 2017 consisted of the following: (thousands) March 24, 2018 December 30, 2017 Principal amount $ 30,000 $ 30,000 Less: unamortized debt issuance costs 1,186 1,256 Debt less unamortized debt issuance costs $ 28,814 $ 28,744

Segment Information (Tables)

Segment Information (Tables)	3 Months Ended
	Mar. 24, 2018
Segment Reporting [Abstract]
Schedule of Segment Reporting Information, by Segment	Segment results for the first quarters ended March 24, 2018 , and March 25, 2017 were as follows: First Quarter Ended, March 24, 2018 (Thousands) Environmental Services Oil Business Corporate and Consolidated Revenues Product revenues $ 6,444 $ 22,566 $ — $ 29,010 Service revenues 51,032 3,105 — 54,137 Total revenues $ 57,476 $ 25,671 $ — $ 83,147 Operating expenses Operating costs 42,725 25,661 — 68,386 Operating depreciation and amortization 1,490 1,389 — 2,879 Profit (loss) before corporate selling, general, and administrative expenses $ 13,261 $ (1,379 ) $ — $ 11,882 Selling, general, and administrative expenses 11,022 11,022 Depreciation and amortization from SG&A 764 764 Total selling, general, and administrative expenses $ 11,786 $ 11,786 Other expense - net 389 389 Operating (loss) (293) Interest expense – net 245 245 (Loss) before income taxes $ (538 ) First Quarter Ended, March 25, 2017 (Thousands) Environmental Services Oil Business Corporate and Consolidated Revenues Product revenues $ 5,724 $ 21,256 $ — $ 26,980 Service revenues 47,492 5,981 — 53,473 Total revenues $ 53,216 $ 27,237 $ — $ 80,453 Operating expenses Operating costs 36,520 24,770 — 61,290 Operating depreciation and amortization 1,746 1,535 — 3,281 Profit before corporate selling, general, and administrative expenses $ 14,950 $ 932 $ — $ 15,882 Selling, general, and administrative expenses 12,341 12,341 Depreciation and amortization from SG&A 851 851 Total selling, general, and administrative expenses $ 13,192 $ 13,192 Other (income) - net (5,006) (5,006) Operating income 7,696 Interest expense – net 87 87 Income before income taxes $ 7,609
Reconciliation of Assets from Segment to Consolidated	Total assets by segment as of March 24, 2018 and December 30, 2017 were as follows: (Thousands) March 24, 2018 December 30, 2017 Total Assets: Environmental Services $ 133,881 $ 131,457 Oil Business 132,652 129,936 Unallocated Corporate Assets 47,985 53,264 Total $ 314,518 $ 314,657

Share-based Compensation (Table

Share-based Compensation (Tables)	3 Months Ended
	Mar. 24, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Schedule of Stock Option Activity	A summary of stock option activity under this Plan is as follows: Outstanding Stock Options Number of Options Outstanding Weighted Average Exercise Price Weighted Average Remaining Contractual Term (in years) Aggregate Intrinsic Value as of Date Listed (in thousands) Options outstanding at December 30, 2017 19,435 $ 7.33 1.23 $ 280 Exercised — — — — Options outstanding at March 24, 2018 19,435 $ 7.33 1.00 $ 301
Schedule of Restricted Stock Unit Activity	The following table summarizes the restricted stock activity for the period ended March 24, 2018 : Restricted Stock (Nonvested Shares) Number of Shares Weighted Average Grant-Date Fair Value Per Share Nonvested shares outstanding at December 30, 2017 685,999 $ 14.52 Granted 116,957 20.35 Vested (134,730 ) 14.42 Nonvested shares outstanding at March 24, 2018 668,226 $ 15.92 The following table shows a summary of restricted share grants and expense resulting from the awards: Compensation Expense (thousands, except for shares total) First Quarter Ended, Unrecognized Expense as of, Recipient of Grant Grant Date Restricted Shares March 24, 2018 March 25, 2017 March 24, 2018 December 30, 2017 Board of Directors April, 2017 14,980 $ 66 $ 66 $ — $ — Members of Management January, 2016 43,208 21 24 80 101 Members of Management February, 2017 146,564 99 93 742 841 Members of Management February, 2018 116,958 122 285 1,648 1,770 Chief Executive Officer February, 2017 500,000 511 174 1,912 2,423
Schedule of Restricted Stock Vesting Percentages	Vesting Table Increase in Stock Price From the Employment Commencement Date to the Vesting Date Total percentage of Restricted Stock Shares to Be Vested Less than $5 per share increase —% $5 per share increase 25% $10 per share increase 50% $15 per share increase 75% $20 or more per share increase 100%

Earnings Per Share (Tables)

Earnings Per Share (Tables)	3 Months Ended
	Mar. 24, 2018
Earnings Per Share [Abstract]
Schedule of Basic and Diluted Earnings Per Share	The following table reconciles the number of shares outstanding for the first quarters of fiscal 2018 and 2017 , respectively, to the number of weighted average basic shares outstanding and the number of weighted average diluted shares outstanding for the purposes of calculating basic and diluted earnings per share: First Quarter Ended, (Thousands) March 24, 2018 March 25, 2017 Net (loss) income $ (102 ) $ 4,817 Less: Income attributable to noncontrolling interest 18 53 Net (loss) income attributable to Heritage-Crystal Clean, Inc. available to common stockholders $ (120 ) $ 4,764 Weighted average basic shares outstanding 22,962 22,353 Dilutive shares from share–based compensation plans — 539 Weighted average diluted shares outstanding 22,962 22,892 Number of anti–dilutive potentially issuable shares excluded from diluted shares outstanding 170 — Net (loss) income per share: basic $ (0.01 ) $ 0.21 Net (loss) income per share: diluted $ (0.01 ) $ 0.21

Organization and Nature of Op35

Organization and Nature of Operations (Details)	3 Months Ended
	Mar. 24, 2018segment
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Number of reportable segments	2

Summary of Significant Accoun36

Summary of Significant Accounting Policies Cumulative Effect of the Changes for Topic 606 Adoption (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 24, 2018	Mar. 25, 2017	Dec. 30, 2017
Statement of Income
Service revenues	$ 54,137	$ 53,473
Total revenues	83,147	80,453
Operating (loss) income	(293)	7,696
(Loss) income before income taxes	(538)	7,609
(Benefit from) provision for income taxes	(436)	2,792
Net (loss) income	(102)	4,817
Net (loss) income attributable to Heritage-Crystal Clean, Inc. common stockholders	(120)	$ 4,764
Balance Sheet
Contract liabilities - net	237		$ 0
Total Current Liabilities	41,081		40,431
Deferred income taxes	9,170		9,556
Total Liabilities	79,065		78,731
Retained earnings	40,971		41,359
Total Heritage-Crystal Clean, Inc. Stockholders' Equity	234,737		235,228
Total Equity	235,453		$ 235,926
Balances Without Adoption of Topic 606
Statement of Income
Service revenues	54,106
Total revenues	83,116
Operating (loss) income	(324)
(Loss) income before income taxes	(569)
(Benefit from) provision for income taxes	(461)
Net (loss) income	(108)
Net (loss) income attributable to Heritage-Crystal Clean, Inc. common stockholders	(126)
Balance Sheet
Contract liabilities - net	0
Total Current Liabilities	40,844
Deferred income taxes	9,145
Total Liabilities	78,803
Retained earnings	41,233
Total Heritage-Crystal Clean, Inc. Stockholders' Equity	234,999
Total Equity	235,715
ASU 2014-09 | Effect of Change Higher/(Lower)
Statement of Income
Service revenues	31
Total revenues	31
Operating (loss) income	31
(Loss) income before income taxes	31
(Benefit from) provision for income taxes	25
Net (loss) income	6
Net (loss) income attributable to Heritage-Crystal Clean, Inc. common stockholders	6
Balance Sheet
Contract liabilities - net	237
Total Current Liabilities	237
Deferred income taxes	25
Total Liabilities	262
Retained earnings	(262)
Total Heritage-Crystal Clean, Inc. Stockholders' Equity	(262)
Total Equity	$ (262)

Revenue - Schedule of Disaggreg

Revenue - Schedule of Disaggregation of Revenue by Major Lines (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 24, 2018	Mar. 25, 2017
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	$ 83,055
Other Revenue	92
Total revenues	$ 83,147	$ 80,453
Payment term	30 days
Parts cleaning, containerized waste, & related products/services
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	$ 39,615
Vacuum Services & Wastewater Treatment
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	11,847
Antifreeze Business
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	3,459
Field Services
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	2,155
Environmental Services - Other
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	400
Re-refinery Product Sales
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	20,485
Oil Collection Services & RFO
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	4,017
Oil Filter Business
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	1,077
Environmental Services
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	57,476
Other Revenue	0
Total revenues	57,476
Environmental Services | Parts cleaning, containerized waste, & related products/services
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	39,615
Environmental Services | Vacuum Services & Wastewater Treatment
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	11,847
Environmental Services | Antifreeze Business
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	3,459
Environmental Services | Field Services
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	2,155
Environmental Services | Environmental Services - Other
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	400
Environmental Services | Re-refinery Product Sales
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	0
Environmental Services | Oil Collection Services & RFO
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	0
Environmental Services | Oil Filter Business
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	0
Oil Business
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	25,579
Other Revenue	92
Total revenues	25,671
Oil Business | Parts cleaning, containerized waste, & related products/services
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	0
Oil Business | Vacuum Services & Wastewater Treatment
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	0
Oil Business | Antifreeze Business
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	0
Oil Business | Field Services
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	0
Oil Business | Environmental Services - Other
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	0
Oil Business | Re-refinery Product Sales
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	20,485
Oil Business | Oil Collection Services & RFO
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	4,017
Oil Business | Oil Filter Business
Disaggregation of Revenue [Line Items]
Revenues from Contracts with Customers	$ 1,077

Revenue - Contract Assets and C

Revenue - Contract Assets and Contract Liabilities from Contracts with Customers (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 24, 2018	Dec. 30, 2017
Revenue from Contract with Customer [Abstract]
Contract assets	$ 44	$ 59
Contract liabilities	281	327
Contract liabilities - net	237	$ 268
Revenue recognized previously included in contract liabilities	$ 31

Accounts Receivable - Component

Accounts Receivable - Components of Accounts Receivable (Details) - USD ($) $ in Thousands	Mar. 24, 2018	Dec. 30, 2017	Dec. 31, 2016
Accounts Receivable, Net [Abstract]
Trade	$ 44,072	$ 43,301
Less: allowance for doubtful accounts	(1,923)	(1,881)	$ (2,176)
Trade - net	42,149	41,420
Related parties	2,042	1,906
Other	2,692	2,165
Total accounts receivable - net	$ 46,883	$ 45,491

Accounts Receivable - Allowance

Accounts Receivable - Allowance for Doubtful Accounts (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 24, 2018	Mar. 25, 2017	Dec. 30, 2017
Allowance for Doubtful Accounts Receivable [Roll Forward]
Balance at beginning of period	$ 1,881	$ 2,176	$ 2,176
Provision for bad debts	286	$ (28)	402
Accounts written off, net of recoveries	(244)		(697)
Balance at end of period	$ 1,923		$ 1,881

Inventory (Details)

Inventory (Details) - USD ($)	3 Months Ended
	Mar. 24, 2018	Mar. 25, 2017	Dec. 30, 2017
Inventory Disclosure [Abstract]
Used oil and processed oil	$ 8,062,000		$ 5,788,000
Solvents and solutions	6,820,000		6,201,000
Drums and supplies	4,785,000		4,430,000
Machines	3,862,000		3,679,000
Other	2,146,000		1,936,000
Total inventory	25,675,000		22,034,000
Less: machine refurbishing reserve	(281,000)		(395,000)
Total inventory - net	25,394,000		$ 21,639,000
Inventory write-down	$ 0	$ 0

Property, Plant, and Equipmen42

Property, Plant, and Equipment (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 24, 2018	Mar. 25, 2017	Dec. 30, 2017
Property, Plant and Equipment [Abstract]
Machinery, vehicles, and equipment	$ 85,683		$ 85,427
Buildings and storage tanks	69,055		69,009
Land	9,557		9,562
Leasehold improvements	5,468		5,427
Construction in progress	11,280		9,378
Assets held for sale	53		53
Total property, plant and equipment	181,096		178,856
Less: accumulated depreciation	(52,592)		(50,737)
Property, plant and equipment - net	128,504		128,119
Equipment at customers	69,388		68,234
Less: accumulated depreciation	(45,915)		(44,922)
Equipment at customers - net	23,473		$ 23,312
Depreciation expense	$ 2,900	$ 3,400

Goodwill and Other Intangible43

Goodwill and Other Intangible Assets - Goodwill (Details) $ in Thousands	3 Months Ended
	Mar. 24, 2018USD ($)reporting_unit	Dec. 30, 2017USD ($)
Goodwill and Intangible Assets Disclosure [Abstract]
Number of reporting units | reporting_unit	2
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	$ 35,532	$ 35,532
Accumulated impairment loss	(3,952)	(3,952)
Goodwill [Roll Forward]
Net book value, beginning balance	31,580
Measurement period adjustments	0
Net book value, ending balance	31,580
Oil Business
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	3,952	3,952
Accumulated impairment loss	(3,952)	(3,952)
Goodwill [Roll Forward]
Net book value, beginning balance	0
Measurement period adjustments	0
Net book value, ending balance	0
Environmental Services
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	31,580	31,580
Accumulated impairment loss	0	$ 0
Goodwill [Roll Forward]
Net book value, beginning balance	31,580
Measurement period adjustments	0
Net book value, ending balance	$ 31,580

Goodwill and Other Intangible44

Goodwill and Other Intangible Assets - Summary of Intangibles (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 24, 2018	Mar. 25, 2017	Dec. 30, 2017
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 33,857		$ 33,867
Accumulated Amortization	17,852		17,135
Net Carrying Amount	16,005		16,732
Amortization of intangible assets	700	$ 800
Finite-Lived Intangible Assets, Amortization Expense, Maturity Schedule [Abstract]
2,018	2,300
2,019	2,600
2,020	2,500
2,021	2,400
2,022	2,100
Customer & supplier relationships
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	23,071		23,077
Accumulated Amortization	9,565		9,027
Net Carrying Amount	$ 13,506		14,050
Useful life	10 years
Software
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 4,724		4,724
Accumulated Amortization	3,954		3,899
Net Carrying Amount	$ 770		825
Useful life	9 years
Non-compete agreements
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 2,945		2,949
Accumulated Amortization	2,705		2,617
Net Carrying Amount	$ 240		332
Useful life	5 years
Patents, formulae, and licenses
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 1,769		1,769
Accumulated Amortization	657		642
Net Carrying Amount	$ 1,112		1,127
Useful life	15 years
Other
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 1,348		1,348
Accumulated Amortization	971		950
Net Carrying Amount	$ 377		$ 398
Useful life	6 years

Accounts Payable (Details)

Accounts Payable (Details) - USD ($) $ in Thousands	Mar. 24, 2018	Dec. 30, 2017
Payables and Accruals [Abstract]
Accounts payable	$ 27,488	$ 25,540
Accounts payable - related parties	361	28
Total accounts payable	$ 27,849	$ 25,568

Debt and Financing Arrangemen46

Debt and Financing Arrangements - Narrative (Details) - USD ($)	Feb. 21, 2017	Mar. 24, 2018	Mar. 25, 2017	Dec. 30, 2017
Debt Instrument [Line Items]
Payments of debt issuance costs		$ 0	$ 1,051,000
Unamortized debt issuance costs		1,186,000		$ 1,256,000
Amortization of Debt Issuance Costs		100,000
Interest costs capitalized, less than $0.1 million for the second quarter and first half of 2016		$ 0
Weighted average interest rate		3.40%	3.50%
Letters of credit outstanding		$ 1,200,000		900,000
Current borrowing capacity		63,800,000		$ 64,100,000
Term Loan
Debt Instrument [Line Items]
Interest costs incurred		$ 300,000	$ 500,000
Credit Agreement
Debt Instrument [Line Items]
Minimum interest coverage ratio	3.5
Maximum total leverage ratio	3
Aggregate consideration limit	$ 10,000,000
Leverage ratio at time of acquisition	3.25
Capital expenditures covenant limit	$ 100,000,000
Percentage of EBITDA	35.00%
Payments of debt issuance costs			1,100,000
Capitalized debt issuance costs			1,100,000
Credit Agreement | Bank Credit Facility
Debt Instrument [Line Items]
Maximum borrowing capacity	$ 95,000,000
Credit Agreement | Bank Credit Facility | Federal Funds Rate
Debt Instrument [Line Items]
Basis spread on variable rate	0.50%
Credit Agreement | Bank Credit Facility | LIBOR
Debt Instrument [Line Items]
Basis spread on variable rate	1.00%
Credit Agreement | Bank Credit Facility | LIBOR | Minimum
Debt Instrument [Line Items]
Basis spread on variable rate	1.75%
Credit Agreement | Bank Credit Facility | LIBOR | Maximum
Debt Instrument [Line Items]
Basis spread on variable rate	2.75%
Credit Agreement | Bank Credit Facility | Bank of America's Prime Rate | Minimum
Debt Instrument [Line Items]
Basis spread on variable rate	0.75%
Credit Agreement | Bank Credit Facility | Bank of America's Prime Rate | Maximum
Debt Instrument [Line Items]
Basis spread on variable rate	1.75%
Credit Agreement | Term Loan
Debt Instrument [Line Items]
Maximum borrowing capacity	$ 30,000,000
Credit Agreement | Revolving Loan Portion
Debt Instrument [Line Items]
Maximum borrowing capacity	$ 65,000,000
Prior Credit Agreement [Member] | Selling, General, and Administrative Expenses
Debt Instrument [Line Items]
Unamortized debt issuance costs			$ 200,000

Debt and Financing Arrangemen47

Debt and Financing Arrangements - Summary of Debt (Details) - USD ($) $ in Thousands	Mar. 24, 2018	Dec. 30, 2017
Debt Disclosure [Abstract]
Principal amount	$ 30,000	$ 30,000
Less: unamortized debt issuance costs	1,186	1,256
Debt less unamortized debt issuance costs	$ 28,814	$ 28,744

Segment Information - Operating

Segment Information - Operating Segment Results (Details) $ in Thousands	3 Months Ended
	Mar. 24, 2018USD ($)segment	Sep. 09, 2017USD ($)	Mar. 25, 2017USD ($)
Segment Reporting [Abstract]
Number of reportable segments | segment	2
Revenues
Product revenues	$ 29,010		$ 26,980
Service revenues	54,137		53,473
Total revenues	83,147		80,453
Operating expenses
Operating costs	68,386		61,290
Operating depreciation and amortization	2,879		3,281
Profit (loss) before corporate selling, general, and administrative expenses	11,882		15,882
Selling, general, and administrative expenses	11,022		12,341
Depreciation and amortization from SG&A	764		851
Total selling, general, and administrative expenses	11,786		13,192
Other expense (income) - net	389		(5,006)
Operating (loss) income	(293)		7,696
Interest expense – net	245		87
(Loss) income before income taxes	(538)		7,609
Segments
Operating expenses
Operating depreciation and amortization
Corporate and Eliminations
Revenues
Product revenues	0		0
Service revenues	0		0
Total revenues	0		0
Operating expenses
Operating costs	0		0
Operating depreciation and amortization	0		0
Profit (loss) before corporate selling, general, and administrative expenses	0		0
Selling, general, and administrative expenses	11,022		12,341
Depreciation and amortization from SG&A	764		851
Total selling, general, and administrative expenses	11,786		13,192
Other expense (income) - net	389		(5,006)
Interest expense – net	245		87
Environmental Services
Revenues
Total revenues	57,476
Environmental Services | Segments
Revenues
Product revenues	6,444		5,724
Service revenues	51,032		47,492
Total revenues	57,476		53,216
Operating expenses
Operating costs	42,725		36,520
Operating depreciation and amortization	1,490		1,746
Profit (loss) before corporate selling, general, and administrative expenses	13,261		14,950
Oil Business
Revenues
Total revenues	25,671
Oil Business | Segments
Revenues
Product revenues	22,566		21,256
Service revenues	3,105		5,981
Total revenues	25,671		27,237
Operating expenses
Operating costs	25,661		24,770
Operating depreciation and amortization	1,389		1,535
Profit (loss) before corporate selling, general, and administrative expenses	$ (1,379)		$ 932

Segment Information - Assets by

Segment Information - Assets by Segment (Details) - USD ($) $ in Thousands	Mar. 24, 2018	Dec. 30, 2017
Segment Reporting Information [Line Items]
Assets	$ 314,518	$ 314,657
Segments | Environmental Services
Segment Reporting Information [Line Items]
Assets	133,881	131,457
Segments | Oil Business
Segment Reporting Information [Line Items]
Assets	132,652	129,936
Unallocated Corporate Assets
Segment Reporting Information [Line Items]
Assets	$ 47,985	$ 53,264

Commitments and Contingencies (

Commitments and Contingencies (Details) - USD ($) $ in Millions	Mar. 24, 2018	Dec. 30, 2017
Commitments and Contingencies Disclosure [Abstract]
Remaining amount committed	$ 16.3	$ 15.6
Loss contingency accrual	$ 4	$ 4.5

Income Taxes (Details)

Income Taxes (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Mar. 24, 2018	Mar. 25, 2017	Dec. 30, 2017
Operating Loss Carryforwards [Line Items]
Deferred tax asset, state and federal NOL		$ 6,300
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative-effect increase due to adoption of ASU				$ (268)
Effective tax rate		81.10%	36.70%
Reserve balance		$ 2,400		2,400
Retained Earnings
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative-effect increase due to adoption of ASU				$ (268)
Tax years 2011 - 2017
Operating Loss Carryforwards [Line Items]
Net operating loss		44,700
Tax year 2011
Operating Loss Carryforwards [Line Items]
Net operating loss		13,700
Tax years 2012 - 2015
Operating Loss Carryforwards [Line Items]
Net operating loss		13,000
Tax years 2011 - 2015
Operating Loss Carryforwards [Line Items]
Net operating loss		26,700
ASU 2016-09
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Excess tax benefits from share-based compensation	$ 2,500
Cumulative-effect increase to deferred tax assets		1,000
ASU 2016-09 | Retained Earnings
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative-effect increase due to adoption of ASU		$ 1,000

Share-based Compensation - Stoc

Share-based Compensation - Stock Options (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 24, 2018	Dec. 30, 2017
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Number of shares authorized	2,602,077
Number of shares available for grant	536,953
Number of Options Outstanding
Options outstanding at Beginning of Period (in shares)	19,435
Exercised (in shares)	0
Options outstanding at End of Period (in shares)	19,435	19,435
Weighted Average Exercise Price
Options outstanding at Beginning of Period (in dollars per share)	$ 7.33
Exercised (in dollars per share)	0
Options outstanding at End of Period (in dollars per share)	$ 7.33	$ 7.33
Weighted Average Remaining Contractual Term and Aggregate Intrinsic Value as of Date Listed
Weighted average remaining contractual term (in years)	1 year	1 year 2 months 23 days
Aggregate intrinsic value as of date listed	$ 301	$ 280

Share-based Compensation - Rest

Share-based Compensation - Restricted Stock Compensation/Awards (Details) - USD ($) $ / shares in Units, $ in Thousands	Mar. 14, 2018	Feb. 28, 2018	Apr. 30, 2017	Feb. 28, 2017	Jan. 31, 2016	Mar. 24, 2018	Mar. 25, 2017	Dec. 30, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted shares granted (in shares)						116,957
Vested (in shares)						134,730
Mr. Recatto
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Closing share price as of employment commencement date (in dollars per share)				$ 15
Restricted stock | Board of Directors
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period (in years)						1 year
Restricted stock | Board of Directors | April, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted shares granted (in shares)			14,980
Compensation Expense						$ 66	$ 66
Unrecognized compensation expense						$ 0		$ 0
Restricted stock | Members of Management
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period (in years)						3 years
Restricted stock | Members of Management | January, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted shares granted (in shares)					43,208
Compensation Expense						$ 21	24
Unrecognized compensation expense						80		101
Restricted stock | Members of Management | February, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted shares granted (in shares)				146,564
Compensation Expense						99	93
Unrecognized compensation expense						742		841
Restricted stock | Members of Management | February, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted shares granted (in shares)		116,958
Compensation Expense						122	285
Unrecognized compensation expense						1,648		1,770
Restricted stock | Chief Executive Officer | February, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted shares granted (in shares)				500,000
Compensation Expense						511	$ 174
Unrecognized compensation expense						1,912		$ 2,423
Restricted stock | Mr. Recatto
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation Expense						500
Accelerated vesting compensation expense						$ 200
Unrecognized compensation expense				$ 1,900
Grants in period (in shares)				500,000
Vesting threshold (in dollars per share)				$ 5
Shares vested upon achievement of share price threshold (in shares)				0
Risk-free rate				1.70%
Expected dividend yield				0.00%
Expected volatility rate				41.73%
Restricted stock | Mr. Recatto | Less than $5 per share increase
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period (in years)						180 days
Vesting percentage				0.00%		50.00%
Restricted stock | Mr. Recatto | $5 per share increase
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage	25.00%			25.00%
Vested (in shares)	125,000

Share-based Compensation - Re54

Share-based Compensation - Restricted Stock Vesting Schedule by Percentage (Details) - Mr. Recatto - Restricted stock - $ / shares	Mar. 14, 2018	Feb. 28, 2017	Mar. 24, 2018
Less than $5 per share increase
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Increase in stock price from employment commencement date (in dollars per share)		$ 5
Total percentage of Restricted Stock Shares to Be Vested		0.00%	50.00%
$5 per share increase
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Increase in stock price from employment commencement date (in dollars per share)		$ 5
Total percentage of Restricted Stock Shares to Be Vested	25.00%	25.00%
$10 per share increase
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Increase in stock price from employment commencement date (in dollars per share)		$ 10
Total percentage of Restricted Stock Shares to Be Vested		50.00%
$15 per share increase
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Increase in stock price from employment commencement date (in dollars per share)		$ 15
Total percentage of Restricted Stock Shares to Be Vested		75.00%
$20 or more per share increase
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Increase in stock price from employment commencement date (in dollars per share)		$ 20
Total percentage of Restricted Stock Shares to Be Vested		100.00%

Share-based Compensation - Nonv

Share-based Compensation - Nonvested Restricted Stock (Details)	3 Months Ended
	Mar. 24, 2018$ / sharesshares
Number of Shares
Nonvested shares outstanding at Beginning of Period (in shares) | shares	685,999
Granted (in shares) | shares	116,957
Vested (in shares) | shares	(134,730)
Nonvested shares outstanding at End of Period (in shares) | shares	668,226
Weighted Average Grant-Date Fair Value Per Share
Nonvested shares outstanding at Beginning of Period (in dollars per share) | $ / shares	$ 14.52
Granted (in dollars per share) | $ / shares	20.35
Vested (in dollars per share) | $ / shares	14.42
Nonvested shares outstanding at End of Period (in dollars per share) | $ / shares	$ 15.92

Share-based Compensation - Empl

Share-based Compensation - Employee Stock Purchase Plan (Details)	3 Months Ended
	Mar. 24, 2018$ / sharesshares
Common stock
Employee Stock Ownership Plan (ESOP) Disclosures [Line Items]
Issuance of common stock – ESPP (in shares)	4,822
Employee Stock Purchase Plan of 2008 | Employee stock
Employee Stock Ownership Plan (ESOP) Disclosures [Line Items]
Shares available employee stock purchase plan (in shares)	145,204
Weighted average fair value per share ESPP (in dollars per share) | $ / shares	$ 21.90

Earnings Per Share (Details)

Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 24, 2018	Mar. 25, 2017
Earnings Per Share [Abstract]
Net (loss) income	$ (102)	$ 4,817
Less: Income attributable to noncontrolling interest	18	53
Net (loss) income attributable to Heritage-Crystal Clean, Inc. common stockholders	$ (120)	$ 4,764
Weighted average basic shares outstanding (in shares)	22,962	22,353
Dilutive shares from share–based compensation plans (in shares)	0	539
Weighted average diluted shares outstanding (in shares)	22,962	22,892
Number of anti–dilutive potentially issuable shares excluded from diluted shares outstanding (in shares)	170	0
Net (loss) income per share: basic (in dollars per share)	$ (0.01)	$ 0.21
Net (loss) income per share: diluted (in dollars per share)	$ (0.01)	$ 0.21

Other Expense (Income) - Net (D

Other Expense (Income) - Net (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 24, 2018	Mar. 25, 2017
Restructuring Cost and Reserve [Line Items]
Other expense (income)	$ 389	$ (5,006)
Partial award		$ 5,100
Facility closing
Restructuring Cost and Reserve [Line Items]
Other expense (income)	$ 300

Subsequent Events (Details)

Subsequent Events (Details) - USD ($) $ in Millions	May 03, 2018	Apr. 13, 2018	Mar. 24, 2018
Subsequent Event [Line Items]
Number of shares available for grant			536,953
Subsequent event
Subsequent Event [Line Items]
Purchase price	$ 5.9
Initial payment	$ 4.2
Subsequent event | Restricted stock | Members of Management | Omnibus Incentive Plan of 2008
Subsequent Event [Line Items]
Grants in period (in shares)		350,000
Number of shares available for grant		612,500
Subsequent event | Restricted stock | Members of Management | Omnibus Incentive Plan of 2008 | Minimum
Subsequent Event [Line Items]
Shares expected to vested		0
Subsequent event | Restricted stock | Members of Management | Omnibus Incentive Plan of 2008 | Maximum
Subsequent Event [Line Items]
Shares expected to vested		612,500