Heritage-Crystal Clean (HCCI) 10-Q 26 Jul 17 2017 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	6 Months Ended
	Jun. 17, 2017	Jul. 24, 2017
Document and Entity Information [Abstract]
Entity Registrant Name	Heritage-Crystal Clean, Inc.
Entity Central Index Key	1,403,431
Current Fiscal Year End Date	--12-30
Entity Filer Category	Accelerated Filer
Document Type	10-Q
Document Period End Date	Jun. 17, 2017
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	Q2
Amendment Flag	false
Entity Common Stock, Shares Outstanding		22,614,700

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 17, 2017	Dec. 31, 2016
Current Assets:
Cash and cash equivalents	$ 25,242	$ 36,610
Accounts receivable - net	44,343	47,533
Inventory - net	18,862	18,558
Other current assets	6,448	6,094
Total Current Assets	94,895	108,795
Property, plant and equipment - net	129,540	131,175
Equipment at customers - net	23,117	23,033
Software and intangible assets - net	18,344	19,821
Goodwill	31,573	31,483
Total Assets	297,469	314,307
Current Liabilities:
Accounts payable	28,861	30,984
Current maturities of long-term debt	0	6,936
Accrued salaries, wages, and benefits	5,177	6,312
Taxes payable	7,474	6,729
Other current liabilities	2,237	3,245
Total Current Liabilities	43,749	54,206
Long-term debt, less current maturities	28,582	56,518
Deferred income taxes	10,821	5,314
Total Liabilities	83,152	116,038
STOCKHOLDERS' EQUITY:
Common stock - 26,000,000 shares authorized at $0.01 par value, 22,604,189 and 22,300,007 shares issued and outstanding at June 17, 2017 and December 31, 2016, respectively	226	223
Additional paid-in capital	188,642	185,099
Retained earnings	24,934	12,227
Total Heritage-Crystal Clean, Inc. Stockholders' Equity	213,802	197,549
Noncontrolling interest	515	720
Total Equity	214,317	198,269
Total Liabilities and Stockholders' Equity	$ 297,469	$ 314,307

Condensed Consolidated Balance3

Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	Jun. 17, 2017	Dec. 31, 2016
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	22,604,189	22,300,007
Common stock, shares outstanding	22,604,189	22,300,007

Condensed Consolidated Statemen

Condensed Consolidated Statements of Income - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 17, 2017	Jun. 18, 2016	Jun. 17, 2017	Jun. 18, 2016
Revenues
Product revenues	$ 31,832	$ 24,695	$ 58,812	$ 48,399
Service revenues	54,550	55,857	108,023	110,606
Total revenues	86,382	80,552	166,835	159,005
Operating expenses
Operating costs	63,270	61,711	124,560	125,959
Selling, general, and administrative expenses	10,575	11,521	22,916	23,729
Depreciation and amortization	4,184	4,118	8,316	8,246
Other (income) - net	(3,027)	(142)	(8,033)	(201)
Operating income	11,380	3,344	19,076	1,272
Interest expense – net	412	451	499	969
Income before income taxes	10,968	2,893	18,577	303
Provision for income taxes	3,982	1,062	6,774	197
Net income	6,986	1,831	11,803	106
Income attributable to noncontrolling interest	52	0	105	42
Net income attributable to Heritage-Crystal Clean, Inc. common stockholders	$ 6,934	$ 1,831	$ 11,698	$ 64
Net income per share: basic (in dollars per share)	$ 0.31	$ 0.08	$ 0.52	$ 0
Net income per share: diluted (in dollars per share)	$ 0.30	$ 0.08	$ 0.51	$ 0
Number of weighted average shares outstanding: basic (in shares)	22,506	22,246	22,430	22,236
Number of weighted average shares outstanding: diluted (in shares)	22,832	22,419	22,729	22,392

Condensed Consolidated Stateme5

Condensed Consolidated Statement of Stockholders' Equity - USD ($) $ in Thousands	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Total Heritage-Crystal Clean, Inc. Stockholders' Equity [Member]	Noncontrolling Interest [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Adjustment adopting ASU 2016-09	$ 1,009			$ 1,009	$ 1,009
Beginning balance (in shares) at Dec. 31, 2016	22,300,007	22,300,007
Beginning balance at Dec. 31, 2016	$ 198,269	$ 223	$ 185,099	12,227	197,549	$ 720
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	11,803			11,698	11,698	105
Distribution	(310)					(310)
Issuance of common stock – ESPP (in shares)		14,367
Issuance of common stock – ESPP	$ 197		197		197
Exercise of stock options (in shares)	216,253	216,253
Exercise of stock options	$ 2,357	$ 2	2,355		2,357
Share-based compensation (in shares)		73,562
Share-based compensation	$ 992	$ 1	991		992
Ending balance (in shares) at Jun. 17, 2017	22,604,189	22,604,189
Ending balance at Jun. 17, 2017	$ 214,317	$ 226	$ 188,642	$ 24,934	$ 213,802	$ 515

Condensed Consolidated Stateme6

Condensed Consolidated Statements of Cash Flows - USD ($)	6 Months Ended
	Jun. 17, 2017	Jun. 18, 2016
Cash flows from Operating Activities:
Net income	$ 11,803,000	$ 106,000
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	8,316,000	8,246,000
Non-cash inventory impairment	0	1,651,000
Bad debt provision	(6,000)	361,000
Share-based compensation	992,000	746,000
Deferred taxes	6,506,000	117,000
Amortization of deferred gain on lease conversion	0	(189,000)
Other, net	991,000	324,000
Changes in operating assets and liabilities:
Decrease (increase) in accounts receivable	3,184,000	(1,895,000)
(Increase) decrease in inventory	(304,000)	1,598,000
(Increase) in other current assets	(356,000)	(1,768,000)
(Decrease) increase in accounts payable	(1,771,000)	2,620,000
(Decrease) increase in accrued expenses	(1,443,000)	2,474,000
Cash provided by operating activities	27,912,000	14,391,000
Cash flows from Investing Activities:
Capital expenditures	(6,333,000)	(8,671,000)
Business acquisitions, net of cash acquired	0	(2,400,000)
Proceeds from the sale of property, plant, and equipment	54,000	0
Cash used in investing activities	(6,279,000)	(11,071,000)
Cash flows from Financing Activities:
Payments on Term loan	(64,195,000)	(1,704,000)
Proceeds from new Term Loan	30,000,000	0
Proceeds under revolving credit facility	4,000,000	0
Payments of revolving credit facility	(4,000,000)	0
Proceeds from the exercise of stock options	2,357,000	0
Proceeds from the issuance of common stock	197,000	222,000
Payments of debt issuance costs	(1,050,000)	0
Distributions to noncontrolling interest	(310,000)	(121,000)
Cash (used in) provided by financing activities	(33,001,000)	(1,603,000)
Net (decrease) increase in cash and cash equivalents	(11,368,000)	1,717,000
Cash and cash equivalents, beginning of period	36,610,000	23,608,000
Cash and cash equivalents, end of period	25,242,000	25,325,000
Supplemental disclosure of cash flow information:
Income taxes paid	208,000	242,000
Cash paid for interest	733,000	956,000
Supplemental disclosure of non-cash information:
Payables for construction in progress	$ 514,000	$ 284,000

Organization and Nature of Oper

Organization and Nature of Operations	6 Months Ended
	Jun. 17, 2017
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”), provide 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's locations are 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’s fiscal year ends on the Saturday closest to December 31. The most recent fiscal year ended on December 31, 2016 . 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	6 Months Ended
	Jun. 17, 2017
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 31, 2016. There have been no material changes in these policies or their application. Recently Issued Accounting Pronouncements Standard Issuance Date Description Our 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 The Company is continuing to evaluate the effect that this accounting standard will have on our consolidated financial position and results of operations. To date, certain personnel have attended technical training concerning this new revenue recognition standard. The Company is working to identify each of the different types of contracts with customers and the various performance obligations associated with each type of contract. The Company is also assessing the changes that will be necessary to our information systems to enable us to capture the information necessary to recognize revenue in accordance with the new standard and comply with the additional disclosure requirements. The guidance permits two methods of adoption: retrospectively to each prior reporting period presented (the full retrospective approach), or retrospectively with the cumulative effect of initially applying the guidance recognized at the date of initial application (the modified retrospective approach). The Company will adopt the standard in the first quarter of fiscal 2018 and currently anticipates applying the modified retrospective approach. 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. Recently issued accounting standards adopted Standard Issuance Date Description Effective Date Effect on the Financial Statements ASU 2016-09 Compensation - Stock Compensation: Improvements to Employee Share-Based Payment Accounting. (Topic 718) March 2016 This update addresses the simplification of accounting for employee share-based payment transactions as it pertains to income taxes, the classification of awards as equity or liabilities, accounting for forfeitures, statutory tax withholding requirements, and certain classifications on the statement of cash flows. Early adoption is permitted. January 1, 2017 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. ASU 2015-11, Simplifying the Measurement of Inventory. (Topic 330) July 2015 This update requires the measurement of inventory at the lower of cost or net realizable value. Net realizable value is the estimated selling price in the ordinary course of business, less reasonably predictable costs of completion, disposal and transportation. January 1, 2017 The adoption of ASU 2015-11 at the start of fiscal 2017 resulted in no impact to our consolidated financial statements. ASU 2014-15 Presentation of Financial Statements - Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern. (Subtopic 205-40) August 2014 This update provides guidance about management’s responsibility to evaluate whether there is substantial doubt about an entity’s ability to continue as a going concern and to provide related footnote disclosures. Early adoption is permitted. December 31, 2016 The adoption of ASU 2015-03 in fiscal 2016 resulted in no impact to our consolidated financial statements. 2015-03 April 2015 These updates require debt issuance costs to be presented in the balance sheet as a direct deduction from the carrying value of the associated debt, and allows for the presentation of debt issuance costs as an asset regardless of whether or not there is an outstanding balance on the line-of-credit arrangement. January 3, 2016 The adoption of ASU 2015-03 resulted in the reclassification of $1.4 million of unamortized debt issuance costs from "Other current assets" to "Term loan, less current maturities" as of January 2, 2016. 2015-16 Business Combinations: Simplifying the Accounting for Measurement-Period Adjustments (Topic 805) September 2015 This update simplifies the accounting for measurement-period adjustments in a business combination by requiring the acquirer to recognize adjustments to provisional amounts identified during the measurement period in the reporting period in which the adjustments are determined. The acquirer is also required to record in the reporting period in which the adjustments are determined the effect on earnings of changes in depreciation, amortization, and other items resulting from the change to the provisional amounts. January 3, 2016 The Company early adopted the amendments of this ASU No. 2015-16 in fiscal 2015 and it did not have an impact on our consolidated financial condition and results of operations.

Business Combinations

Business Combinations	6 Months Ended
	Jun. 17, 2017
Business Combinations [Abstract]
Business Combinations	BUSINESS COMBINATIONS On December 2, 2016, the Company purchased the assets of Recycle Engine Coolant, Inc. ("REC"). The purchase price for the acquisition was $0.7 million , including $0.1 million placed into escrow. The Company purchased the assets of REC in order to expand its antifreeze recycling capabilities. On March 24, 2016, the Company purchased the assets of Phoenix Environmental Services, Inc. and Pipeline Video and Cleaning North Corporation (together "Phoenix Environmental"). The purchase price for the acquisition was $2.7 million , including $0.3 million placed into escrow. The Company purchased the assets of Phoenix Environmental in order to expand its service coverage area into the Pacific Northwest. During the measurement period, the Company made adjustments to the provisional amounts reported as the estimated fair values of assets acquired as part of the Phoenix Environmental business combination. Compared to the provisional value reported as of December 31, 2016, the fair values presented in the table below reflect a decrease to accounts receivable of $12 thousand , a decrease to property, plant, & equipment of $77 thousand , and an increase to goodwill of $89 thousand . Factors leading to goodwill being recognized are the Company's expectations of synergies from integrating Phoenix Environmental into the Company as well as the value of intangible assets that are not separately recognized, such as assembled workforce. The following table summarizes the estimated fair values of the assets acquired and liabilities assumed, net of cash acquired, related to each acquisition: (Thousands) Phoenix Environmental REC Accounts receivable $ 260 $ 80 Inventory 27 56 Property, plant, & equipment 398 457 Equipment at customers 38 — Intangible assets 700 132 Goodwill 1,245 — Total purchase price, net of cash acquired $ 2,668 $ 725

Accounts Receivable

Accounts Receivable	6 Months Ended
	Jun. 17, 2017
Accounts Receivable, Net [Abstract]
Accounts Receivable	ACCOUNTS RECEIVABLE Accounts receivable consisted of the following: (Thousands) June 17, December 31, Trade $ 44,682 $ 42,332 Less: allowance for doubtful accounts 1,843 2,176 Trade - net 42,839 40,156 Related parties 814 1,324 Other 690 6,053 Total accounts receivable - net $ 44,343 $ 47,533 The following table provides the changes in the Company’s allowance for doubtful accounts for the first half ended June 17, 2017 and the fiscal year ended December 31, 2016 : For the First Half Ended, For the Fiscal Year Ended, (Thousands) June 17, December 31, Balance at beginning of period $ 2,176 $ 2,207 Provision for bad debts (6 ) 687 Accounts written off, net of recoveries (327 ) (718 ) Balance at end of period $ 1,843 $ 2,176

Inventory

Inventory	6 Months Ended
	Jun. 17, 2017
Inventory Disclosure [Abstract]
Inventory	INVENTORY The carrying value of inventory consisted of the following: (Thousands) June 17, December 31, Used oil and processed oil $ 5,815 $ 5,493 Solvents and solutions 5,692 5,014 Drums and supplies 3,562 3,790 Machines 2,517 2,576 Other 1,639 1,899 Total inventory 19,225 18,772 Less: machine refurbishing reserve 363 214 Total inventory - net $ 18,862 $ 18,558 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 market, 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 second quarter of 2017, compared to a write down of $0.2 million in the second quarter of 2016. There were no inventory write-downs for the first half of fiscal 2017 and $1.7 million of inventory write-downs the first half of fiscal 2016.

Property, Plant, and Equipment

Property, Plant, and Equipment	6 Months Ended
	Jun. 17, 2017
Property, Plant and Equipment [Abstract]
Property, Plant, and Equipment	PROPERTY, PLANT, AND EQUIPMENT Property, plant, and equipment consisted of the following: (Thousands) June 17, December 31, Machinery, vehicles, and equipment $ 79,018 $ 78,592 Buildings and storage tanks 69,136 69,977 Land 10,366 10,363 Leasehold improvements 4,946 4,876 Construction in progress 11,914 8,646 Assets held for sale 61 177 Total property, plant and equipment 175,441 172,631 Less: accumulated depreciation (45,901 ) (41,456 ) Property, plant and equipment - net $ 129,540 $ 131,175 (Thousands) June 17, December 31, Equipment at customers $ 65,663 $ 63,502 Less: accumulated depreciation (42,546 ) (40,469 ) Equipment at customers - net $ 23,117 $ 23,033 Depreciation expense for both second quarters ended June 17, 2017 and June 18, 2016 was $3.4 million . Depreciation expense for the first half ended June 17, 2017, and the first half ended June 18, 2016 was $6.8 million and $6.7 million , respectively.

Goodwill and Other Intangible A

Goodwill and Other Intangible Assets	6 Months Ended
	Jun. 17, 2017
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, and the Company does not aggregate reporting units for purposes of impairment testing. The following table shows changes to our goodwill balances by segment from December 31, 2016, to June 17, 2017: (Thousands) Oil Business Environmental Services Total Goodwill at January 2, 2016 Gross carrying amount $ 3,952 $ 30,325 $ 34,277 Accumulated impairment loss (3,952 ) — (3,952 ) Net book value at January 2, 2016 $ — $ 30,325 $ 30,325 Acquisitions — 1,158 1,158 Goodwill at December 31, 2016 Gross carrying amount 3,952 31,483 35,435 Accumulated impairment loss (3,952 ) — (3,952 ) Net book value at December 31, 2016 $ — $ 31,483 $ 31,483 Measurement period adjustments — 90 — Goodwill at June 17, 2017 Gross carrying amount 3,952 31,573 35,525 Accumulated impairment loss (3,952 ) — (3,952 ) Net book value at June 17, 2017 $ — $ 31,573 $ 31,573 Following is a summary of software and other intangible assets: June 17, 2017 December 31, 2016 (Thousands) Gross Carrying Amount Accumulated Amortization Net Carrying Amount Gross Carrying Amount Accumulated Amortization Net Carrying Amount Customer & supplier relationships $ 23,050 $ 7,763 $ 15,287 $ 23,045 $ 6,682 $ 16,363 Software 4,604 3,768 836 4,573 3,655 918 Non-compete agreements 2,937 2,381 556 2,934 2,180 754 Patents, formulae, and licenses 1,769 607 1,162 1,769 576 1,193 Other 1,348 845 503 1,348 755 593 Total software and intangible assets $ 33,708 $ 15,364 $ 18,344 $ 33,669 $ 13,848 $ 19,821 Amortization expense was $0.8 million for the second quarter ended June 17, 2017 and $0.7 million for second quarter ended June 18, 2016 . Amortization expense was $1.5 million for the first half ended June 17, 2017 and $1.5 million for the first half ended June 18, 2016. 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 2017 and for fiscal years 2018, 2019, 2020, and 2021 is $1.7 million , $3.0 million , $2.6 million , $2.5 million , and $2.4 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.

Debt and Financing Arrangements

Debt and Financing Arrangements	6 Months Ended
	Jun. 17, 2017
Debt Disclosure [Abstract]
Debt and Financing Arrangements	DEBT AND FINANCING ARRANGEMENTS Bank Credit Facility On February 21, 2017, the Company entered into a new Credit Agreement ("Credit Agreement") replacing the prior Credit Agreement ("Prior Credit Agreement") dated as of June 29, 2015. The 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 New 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 New Credit Agreement are secured by a security interest in substantially all of the Company's tangible and intangible assets. In June 2017, the Company entered into a First Amendment to the Credit Agreement that expands the Company's ability to make dispositions without bank group approval. As of the Effective date of February 21, 2017 , the effective interest rate on the term loan was 3.28% and the effective rate on the revolving loan was 3.28% . 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 half of fiscal 2017, the Company paid and capitalized $1.1 million of debt issuance costs pertaining to the New Credit Agreement and charged $0.2 million of unamortized debt issuance costs pertaining to the Prior Credit Agreement to selling, general, and administrative expenses. Debt at June 17, 2017 and December 31, 2016 consisted of the following: (thousands) June 17, 2017 December 31, 2016 Principal amount $ 30,000 $ 64,195 Less: unamortized debt issuance costs 1,418 741 Debt less unamortized debt issuance costs $ 28,582 $ 63,454 During the second quarter of fiscal 2017 , the Company recorded interest of $0.4 million on the term loan. During the first half of fiscal 2017, the Company recorded interest of $0.9 million on the term loan. During the second quarter of fiscal 2016, the Company recorded interest of $0.5 million on the Prior Credit Agreement term loans and capitalized less than $0.1 million for various capital projects. During the first half of fiscal 2016, the Company recorded interest of $1.0 million on the term loan, of which less than $0.1 million was capitalized for various capital projects. The Company's weighted average interest rate for all debt as of June 17, 2017 and June 18, 2016 was 3.8% . As of June 17, 2017 and December 31, 2016 , the Company was in compliance with all covenants under both credit agreements. As of June 17, 2017 and December 31, 2016 , the Company had $2.4 million and $3.0 million of standby letters of credit issued, respectively, and $62.6 million and $27.6 million was available for borrowing under the revolving credit facility, respectively. We believe that the carrying value of our new debt balance at June 17, 2017 approximates fair value.

Segment Information

Segment Information	6 Months Ended
	Jun. 17, 2017
Segment Reporting [Abstract]
Segment Information	SEGMENT INFORMATION The Company reports in two 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. Operating segment results for the second quarters ended June 17, 2017 , and June 18, 2016 were as follows: Second Quarter Ended, June 17, 2017 (Thousands) Environmental Services Oil Business Corporate and Consolidated Revenues Product revenues $ 5,868 $ 25,964 $ — $ 31,832 Service revenues 49,225 5,325 — 54,550 Total revenues $ 55,093 $ 31,289 $ — $ 86,382 Operating expenses Operating costs 36,601 26,669 — 63,270 Operating depreciation and amortization 1,801 1,535 — 3,336 Profit before corporate selling, general, and administrative expenses $ 16,691 $ 3,085 $ — $ 19,776 Selling, general, and administrative expenses 10,575 10,575 Depreciation and amortization from SG&A 848 848 Total selling, general, and administrative expenses $ 11,423 $ 11,423 Other (income) - net (3,027) (3,027) Operating income 11,380 Interest expense – net 412 412 Income before income taxes $ 10,968 Second Quarter Ended, June 18, 2016 (Thousands) Environmental Services Oil Business Corporate and Consolidated Revenues Product revenues $ 5,106 $ 19,589 $ — $ 24,695 Service revenues 47,331 8,526 — 55,857 Total revenues $ 52,437 $ 28,115 $ — $ 80,552 Operating expenses Operating costs 35,631 26,080 — 61,711 Operating depreciation and amortization 1,710 1,591 — 3,301 Profit before corporate selling, general, and administrative expenses $ 15,096 $ 444 $ — $ 15,540 Selling, general, and administrative expenses 11,521 11,521 Depreciation and amortization from SG&A 817 817 Total selling, general, and administrative expenses $ 12,338 $ 12,338 Other (income) - net (142) (142) Operating income 3,344 Interest expense – net 451 451 Income before income taxes $ 2,893 First Half Ended, June 17, 2017 (Thousands) Environmental Services Oil Business Corporate and Consolidated Revenues Product revenues $ 11,592 $ 47,220 $ — $ 58,812 Service revenues 96,716 11,307 — 108,023 Total revenues $ 108,308 $ 58,527 $ — $ 166,835 Operating expenses Operating costs 73,121 51,439 — 124,560 Operating depreciation and amortization 3,547 3,070 — 6,617 Profit before corporate selling, general, and administrative expenses $ 31,640 $ 4,018 $ — $ 35,658 Selling, general, and administrative expenses 22,916 22,916 Depreciation and amortization from SG&A 1,699 1,699 Total selling, general, and administrative expenses $ 24,615 $ 24,615 Other (income) - net (8,033) (8,033) Operating income 19,076 Interest expense – net 499 499 Income before income taxes $ 18,577 First Half Ended, June 18, 2016 (Thousands) Environmental Services Oil Business Corporate and Consolidated Revenues Product revenues $ 10,135 $ 38,264 $ — $ 48,399 Service revenues 94,663 15,943 — 110,606 Total revenues $ 104,798 $ 54,207 $ — $ 159,005 Operating expenses Operating costs 72,436 53,523 — 125,959 Operating depreciation and amortization 3,424 3,171 — 6,595 Profit (loss) before corporate selling, general, and administrative expenses $ 28,938 $ (2,487 ) $ — $ 26,451 Selling, general, and administrative expenses 23,729 23,729 Depreciation and amortization from SG&A 1,651 1,651 Total selling, general, and administrative expenses $ 25,380 $ 25,380 Other (income) - net (201) (201) Operating income 1,272 Interest expense – net 969 969 Income before income taxes $ 303 Total assets by segment as of June 17, 2017 and December 31, 2016 were as follows: (Thousands) June 17, 2017 December 31, 2016 Total Assets: Environmental Services $ 130,944 $ 129,506 Oil Business 128,596 135,323 Unallocated Corporate Assets 37,929 49,478 Total $ 297,469 $ 314,307 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	6 Months Ended
	Jun. 17, 2017
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 $16.7 million as of June 17, 2017 , and $9.7 million as of December 31, 2016, 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 June 17, 2017 and December 31, 2016 , the Company had accrued $5.6 million and $5.5 million related to loss contingencies and other contingent liabilities, respectively.

Income Taxes

Income Taxes	6 Months Ended
	Jun. 17, 2017
Income Tax Disclosure [Abstract]
Income Taxes	INCOME TAXES 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 2015. Therefore, the Company recorded a noncurrent deferred tax liability to reflect 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 in fiscal 2011, which will begin to expire in 2031. The NOL as of June 17, 2017 was $32.9 million , and the remaining deferred tax asset related to the Company’s state and federal NOL was a tax effected balance of $12.5 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 second quarter of fiscal 2017 was 36.3% compared to 36.7% in the second quarter of fiscal 2016 . The Company’s effective rate for the first half of fiscal 2017 was 36.5% compared to 65.0% in the first half of fiscal 2016. The rate decrease is primarily attributed to the previous year’s first half effect of certain state income taxes which are computed on a tax base that reflects substantial modifications to federal taxable income, and that had created comparatively high tax expense due to relatively low year-to-date pre-tax income in the first half of 2016. 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 June 17, 2017 and December 31, 2016 . The gross unrecognized tax benefits would, if recognized, decrease the Company's effective tax rate.

Share-based Compensation

Share-based Compensation	6 Months Ended
	Jun. 17, 2017
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 1,902,077 plus any common stock that becomes available for issuance pursuant to the reusage provision of the Plan. As of June 17, 2017 , the number of shares available for issuance under the Plan was 725,361 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 31, 2016 514,287 $ 11.00 1.33 $ 2,414 Exercised (216,253 ) 10.90 — — Options outstanding at June 17, 2017 298,034 $ 11.08 0.85 $ 1,004 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 shares grants and expense resulting from the awards: Compensation Expense (thousands except for shares total) First Half Ended, Unrecognized Expense as of Recipient of Grant Grant Date Restricted Shares June 17, 2017 June 18, 2016 June 17, 2017 December 31, 2016 Board of Directors April, 2017 28,674 $ 113 $ 132 $ 134 $ — Members of Management February, 2015 38,732 51 57 59 170 Members of Management January, 2016 43,208 48 55 160 258 Members of Management February, 2017 146,564 200 264 1,183 2,028 Chief Executive Officer February, 2017 500,000 455 — 3,080 — 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 , then no shares shall vest. During the first half of fiscal 2017, the Company recorded approximately $0.5 million of compensation expense related to this award. In the future, the Company expects to recognize compensation expense of approximately $3.1 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 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 weighted average closing price of the Company's common stock increases by the marginal levels set forth in the above vesting table for 180 consecutive days during any 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. The following table summarizes the restricted stock activity for the period ended June 17, 2017 : Restricted Stock (Nonvested Shares) Number of Shares Weighted Average Grant-Date Fair Value Per Share Nonvested shares outstanding at December 31, 2016 136,171 $ 12.42 Granted 659,842 15.11 Vested (96,636 ) 13.16 Nonvested shares outstanding at June 17, 2017 699,377 $ 14.51 Employee Stock Purchase Plan As of June 17, 2017 , the Company had reserved 161,812 shares of common stock available for purchase under the Employee Stock Purchase Plan of 2008 . In the first half of fiscal 2017 , employees purchased 14,367 shares of the Company’s common stock with a weighted average fair market value of $14.44 per share.

Earnings Per Share

Earnings Per Share	6 Months Ended
	Jun. 17, 2017
Earnings Per Share [Abstract]
Earnings Per Share	EARNINGS PER SHARE The following table reconciles the number of shares outstanding for the second quarters and the first half ended of fiscal 2017 and 2016 , 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: Second Quarter Ended, First Half Ended, (Thousands) June 17, 2017 June 18, 2016 June 17, 2017 June 18, 2016 Net income $ 6,986 $ 1,831 $ 11,803 $ 106 Less: Income attributable to noncontrolling interest 52 — 105 42 Net income attributable to Heritage-Crystal Clean, Inc. available to common stockholders $ 6,934 $ 1,831 $ 11,698 $ 64 Weighted average basic shares outstanding 22,506 22,246 22,430 22,236 Dilutive shares from share–based compensation plans 326 173 299 156 Weighted average diluted shares outstanding 22,832 22,419 22,729 22,392 Net income per share: basic $ 0.31 $ 0.08 $ 0.52 $ — Net income per share: diluted $ 0.30 $ 0.08 $ 0.51 $ —

Other Expense (Income)

Other Expense (Income)	6 Months Ended
	Jun. 17, 2017
Other Income and Expenses [Abstract]
Other Expense (Income)	OTHER EXPENSE (INCOME) Other expense (income) for the first half of fiscal 2017 includes a gain of $5.1 million received in the first quarter of fiscal 2017 as a result of having received a partial award for a claim made in arbitration and a gain of $3.6 million received during the second quarter of fiscal 2017 from a settlement agreement, both of which were related to our acquisition of FCC Environmental, LLC and International Petroleum Corp. of Delaware in 2014.

Subsequent Events

Subsequent Events	6 Months Ended
	Jun. 17, 2017
Subsequent Events [Abstract]
Subsequent Events	SUBSEQUENT EVENTS On June 28, 2017, the Company entered into a Transition Agreement (“Agreement”) with its former Chief Operating Officer. Pursuant to the terms of the Agreement, the Company has eliminated the position of Chief Operating Officer and will incur a severance charge of approximately $1.2 million in the third quarter of fiscal 2017.

Summary of Significant Accoun22

Summary of Significant Accounting Policies (Policies)	6 Months Ended
	Jun. 17, 2017
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 31, 2016 . 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	Standard Issuance Date Description Our 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 The Company is continuing to evaluate the effect that this accounting standard will have on our consolidated financial position and results of operations. To date, certain personnel have attended technical training concerning this new revenue recognition standard. The Company is working to identify each of the different types of contracts with customers and the various performance obligations associated with each type of contract. The Company is also assessing the changes that will be necessary to our information systems to enable us to capture the information necessary to recognize revenue in accordance with the new standard and comply with the additional disclosure requirements. The guidance permits two methods of adoption: retrospectively to each prior reporting period presented (the full retrospective approach), or retrospectively with the cumulative effect of initially applying the guidance recognized at the date of initial application (the modified retrospective approach). The Company will adopt the standard in the first quarter of fiscal 2018 and currently anticipates applying the modified retrospective approach. 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. Recently issued accounting standards adopted Standard Issuance Date Description Effective Date Effect on the Financial Statements ASU 2016-09 Compensation - Stock Compensation: Improvements to Employee Share-Based Payment Accounting. (Topic 718) March 2016 This update addresses the simplification of accounting for employee share-based payment transactions as it pertains to income taxes, the classification of awards as equity or liabilities, accounting for forfeitures, statutory tax withholding requirements, and certain classifications on the statement of cash flows. Early adoption is permitted. January 1, 2017 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. ASU 2015-11, Simplifying the Measurement of Inventory. (Topic 330) July 2015 This update requires the measurement of inventory at the lower of cost or net realizable value. Net realizable value is the estimated selling price in the ordinary course of business, less reasonably predictable costs of completion, disposal and transportation. January 1, 2017 The adoption of ASU 2015-11 at the start of fiscal 2017 resulted in no impact to our consolidated financial statements. ASU 2014-15 Presentation of Financial Statements - Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern. (Subtopic 205-40) August 2014 This update provides guidance about management’s responsibility to evaluate whether there is substantial doubt about an entity’s ability to continue as a going concern and to provide related footnote disclosures. Early adoption is permitted. December 31, 2016 The adoption of ASU 2015-03 in fiscal 2016 resulted in no impact to our consolidated financial statements. 2015-03 April 2015 These updates require debt issuance costs to be presented in the balance sheet as a direct deduction from the carrying value of the associated debt, and allows for the presentation of debt issuance costs as an asset regardless of whether or not there is an outstanding balance on the line-of-credit arrangement. January 3, 2016 The adoption of ASU 2015-03 resulted in the reclassification of $1.4 million of unamortized debt issuance costs from "Other current assets" to "Term loan, less current maturities" as of January 2, 2016. 2015-16 Business Combinations: Simplifying the Accounting for Measurement-Period Adjustments (Topic 805) September 2015 This update simplifies the accounting for measurement-period adjustments in a business combination by requiring the acquirer to recognize adjustments to provisional amounts identified during the measurement period in the reporting period in which the adjustments are determined. The acquirer is also required to record in the reporting period in which the adjustments are determined the effect on earnings of changes in depreciation, amortization, and other items resulting from the change to the provisional amounts. January 3, 2016 The Company early adopted the amendments of this ASU No. 2015-16 in fiscal 2015 and it did not have an impact on our consolidated financial condition and results of operations.

Summary of Significant Accoun23

Summary of Significant Accounting Policies (Tables)	6 Months Ended
	Jun. 17, 2017
Accounting Policies [Abstract]
Schedule of New Accounting Pronouncements and Changes in Accounting Principles	Standard Issuance Date Description Our 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 The Company is continuing to evaluate the effect that this accounting standard will have on our consolidated financial position and results of operations. To date, certain personnel have attended technical training concerning this new revenue recognition standard. The Company is working to identify each of the different types of contracts with customers and the various performance obligations associated with each type of contract. The Company is also assessing the changes that will be necessary to our information systems to enable us to capture the information necessary to recognize revenue in accordance with the new standard and comply with the additional disclosure requirements. The guidance permits two methods of adoption: retrospectively to each prior reporting period presented (the full retrospective approach), or retrospectively with the cumulative effect of initially applying the guidance recognized at the date of initial application (the modified retrospective approach). The Company will adopt the standard in the first quarter of fiscal 2018 and currently anticipates applying the modified retrospective approach. 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. Recently issued accounting standards adopted Standard Issuance Date Description Effective Date Effect on the Financial Statements ASU 2016-09 Compensation - Stock Compensation: Improvements to Employee Share-Based Payment Accounting. (Topic 718) March 2016 This update addresses the simplification of accounting for employee share-based payment transactions as it pertains to income taxes, the classification of awards as equity or liabilities, accounting for forfeitures, statutory tax withholding requirements, and certain classifications on the statement of cash flows. Early adoption is permitted. January 1, 2017 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. ASU 2015-11, Simplifying the Measurement of Inventory. (Topic 330) July 2015 This update requires the measurement of inventory at the lower of cost or net realizable value. Net realizable value is the estimated selling price in the ordinary course of business, less reasonably predictable costs of completion, disposal and transportation. January 1, 2017 The adoption of ASU 2015-11 at the start of fiscal 2017 resulted in no impact to our consolidated financial statements. ASU 2014-15 Presentation of Financial Statements - Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern. (Subtopic 205-40) August 2014 This update provides guidance about management’s responsibility to evaluate whether there is substantial doubt about an entity’s ability to continue as a going concern and to provide related footnote disclosures. Early adoption is permitted. December 31, 2016 The adoption of ASU 2015-03 in fiscal 2016 resulted in no impact to our consolidated financial statements. 2015-03 April 2015 These updates require debt issuance costs to be presented in the balance sheet as a direct deduction from the carrying value of the associated debt, and allows for the presentation of debt issuance costs as an asset regardless of whether or not there is an outstanding balance on the line-of-credit arrangement. January 3, 2016 The adoption of ASU 2015-03 resulted in the reclassification of $1.4 million of unamortized debt issuance costs from "Other current assets" to "Term loan, less current maturities" as of January 2, 2016. 2015-16 Business Combinations: Simplifying the Accounting for Measurement-Period Adjustments (Topic 805) September 2015 This update simplifies the accounting for measurement-period adjustments in a business combination by requiring the acquirer to recognize adjustments to provisional amounts identified during the measurement period in the reporting period in which the adjustments are determined. The acquirer is also required to record in the reporting period in which the adjustments are determined the effect on earnings of changes in depreciation, amortization, and other items resulting from the change to the provisional amounts. January 3, 2016 The Company early adopted the amendments of this ASU No. 2015-16 in fiscal 2015 and it did not have an impact on our consolidated financial condition and results of operations.

Business Combinations (Tables)

Business Combinations (Tables)	6 Months Ended
	Jun. 17, 2017
Business Combinations [Abstract]
Schedule of Business Acquisitions, by Acquisition	The following table summarizes the estimated fair values of the assets acquired and liabilities assumed, net of cash acquired, related to each acquisition: (Thousands) Phoenix Environmental REC Accounts receivable $ 260 $ 80 Inventory 27 56 Property, plant, & equipment 398 457 Equipment at customers 38 — Intangible assets 700 132 Goodwill 1,245 — Total purchase price, net of cash acquired $ 2,668 $ 725

Accounts Receivable (Tables)

Accounts Receivable (Tables)	6 Months Ended
	Jun. 17, 2017
Accounts Receivable, Net [Abstract]
Schedule of Accounts, Notes, Loans and Financing Receivable	Accounts receivable consisted of the following: (Thousands) June 17, December 31, Trade $ 44,682 $ 42,332 Less: allowance for doubtful accounts 1,843 2,176 Trade - net 42,839 40,156 Related parties 814 1,324 Other 690 6,053 Total accounts receivable - net $ 44,343 $ 47,533 The following table provides the changes in the Company’s allowance for doubtful accounts for the first half ended June 17, 2017 and the fiscal year ended December 31, 2016 : For the First Half Ended, For the Fiscal Year Ended, (Thousands) June 17, December 31, Balance at beginning of period $ 2,176 $ 2,207 Provision for bad debts (6 ) 687 Accounts written off, net of recoveries (327 ) (718 ) Balance at end of period $ 1,843 $ 2,176

Inventory (Tables)

Inventory (Tables)	6 Months Ended
	Jun. 17, 2017
Inventory Disclosure [Abstract]
Schedule of Inventory	The carrying value of inventory consisted of the following: (Thousands) June 17, December 31, Used oil and processed oil $ 5,815 $ 5,493 Solvents and solutions 5,692 5,014 Drums and supplies 3,562 3,790 Machines 2,517 2,576 Other 1,639 1,899 Total inventory 19,225 18,772 Less: machine refurbishing reserve 363 214 Total inventory - net $ 18,862 $ 18,558

Property, Plant, and Equipment

Property, Plant, and Equipment (Tables)	6 Months Ended
	Jun. 17, 2017
Property, Plant and Equipment [Abstract]
Summary of Property, Plant, and Equipment	Property, plant, and equipment consisted of the following: (Thousands) June 17, December 31, Machinery, vehicles, and equipment $ 79,018 $ 78,592 Buildings and storage tanks 69,136 69,977 Land 10,366 10,363 Leasehold improvements 4,946 4,876 Construction in progress 11,914 8,646 Assets held for sale 61 177 Total property, plant and equipment 175,441 172,631 Less: accumulated depreciation (45,901 ) (41,456 ) Property, plant and equipment - net $ 129,540 $ 131,175 (Thousands) June 17, December 31, Equipment at customers $ 65,663 $ 63,502 Less: accumulated depreciation (42,546 ) (40,469 ) Equipment at customers - net $ 23,117 $ 23,033

Goodwill and Other Intangible28

Goodwill and Other Intangible Assets (Tables)	6 Months Ended
	Jun. 17, 2017
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Goodwill	The following table shows changes to our goodwill balances by segment from December 31, 2016, to June 17, 2017: (Thousands) Oil Business Environmental Services Total Goodwill at January 2, 2016 Gross carrying amount $ 3,952 $ 30,325 $ 34,277 Accumulated impairment loss (3,952 ) — (3,952 ) Net book value at January 2, 2016 $ — $ 30,325 $ 30,325 Acquisitions — 1,158 1,158 Goodwill at December 31, 2016 Gross carrying amount 3,952 31,483 35,435 Accumulated impairment loss (3,952 ) — (3,952 ) Net book value at December 31, 2016 $ — $ 31,483 $ 31,483 Measurement period adjustments — 90 — Goodwill at June 17, 2017 Gross carrying amount 3,952 31,573 35,525 Accumulated impairment loss (3,952 ) — (3,952 ) Net book value at June 17, 2017 $ — $ 31,573 $ 31,573
Schedule of Intangible Assets	Following is a summary of software and other intangible assets: June 17, 2017 December 31, 2016 (Thousands) Gross Carrying Amount Accumulated Amortization Net Carrying Amount Gross Carrying Amount Accumulated Amortization Net Carrying Amount Customer & supplier relationships $ 23,050 $ 7,763 $ 15,287 $ 23,045 $ 6,682 $ 16,363 Software 4,604 3,768 836 4,573 3,655 918 Non-compete agreements 2,937 2,381 556 2,934 2,180 754 Patents, formulae, and licenses 1,769 607 1,162 1,769 576 1,193 Other 1,348 845 503 1,348 755 593 Total software and intangible assets $ 33,708 $ 15,364 $ 18,344 $ 33,669 $ 13,848 $ 19,821

Debt and Financing Arrangemen29

Debt and Financing Arrangements (Tables)	6 Months Ended
	Jun. 17, 2017
Debt Disclosure [Abstract]
Schedule of Debt	Debt at June 17, 2017 and December 31, 2016 consisted of the following: (thousands) June 17, 2017 December 31, 2016 Principal amount $ 30,000 $ 64,195 Less: unamortized debt issuance costs 1,418 741 Debt less unamortized debt issuance costs $ 28,582 $ 63,454

Segment Information (Tables)

Segment Information (Tables)	6 Months Ended
	Jun. 17, 2017
Segment Reporting [Abstract]
Schedule of Segment Reporting Information, by Segment	Operating segment results for the second quarters ended June 17, 2017 , and June 18, 2016 were as follows: Second Quarter Ended, June 17, 2017 (Thousands) Environmental Services Oil Business Corporate and Consolidated Revenues Product revenues $ 5,868 $ 25,964 $ — $ 31,832 Service revenues 49,225 5,325 — 54,550 Total revenues $ 55,093 $ 31,289 $ — $ 86,382 Operating expenses Operating costs 36,601 26,669 — 63,270 Operating depreciation and amortization 1,801 1,535 — 3,336 Profit before corporate selling, general, and administrative expenses $ 16,691 $ 3,085 $ — $ 19,776 Selling, general, and administrative expenses 10,575 10,575 Depreciation and amortization from SG&A 848 848 Total selling, general, and administrative expenses $ 11,423 $ 11,423 Other (income) - net (3,027) (3,027) Operating income 11,380 Interest expense – net 412 412 Income before income taxes $ 10,968 Second Quarter Ended, June 18, 2016 (Thousands) Environmental Services Oil Business Corporate and Consolidated Revenues Product revenues $ 5,106 $ 19,589 $ — $ 24,695 Service revenues 47,331 8,526 — 55,857 Total revenues $ 52,437 $ 28,115 $ — $ 80,552 Operating expenses Operating costs 35,631 26,080 — 61,711 Operating depreciation and amortization 1,710 1,591 — 3,301 Profit before corporate selling, general, and administrative expenses $ 15,096 $ 444 $ — $ 15,540 Selling, general, and administrative expenses 11,521 11,521 Depreciation and amortization from SG&A 817 817 Total selling, general, and administrative expenses $ 12,338 $ 12,338 Other (income) - net (142) (142) Operating income 3,344 Interest expense – net 451 451 Income before income taxes $ 2,893 First Half Ended, June 17, 2017 (Thousands) Environmental Services Oil Business Corporate and Consolidated Revenues Product revenues $ 11,592 $ 47,220 $ — $ 58,812 Service revenues 96,716 11,307 — 108,023 Total revenues $ 108,308 $ 58,527 $ — $ 166,835 Operating expenses Operating costs 73,121 51,439 — 124,560 Operating depreciation and amortization 3,547 3,070 — 6,617 Profit before corporate selling, general, and administrative expenses $ 31,640 $ 4,018 $ — $ 35,658 Selling, general, and administrative expenses 22,916 22,916 Depreciation and amortization from SG&A 1,699 1,699 Total selling, general, and administrative expenses $ 24,615 $ 24,615 Other (income) - net (8,033) (8,033) Operating income 19,076 Interest expense – net 499 499 Income before income taxes $ 18,577 First Half Ended, June 18, 2016 (Thousands) Environmental Services Oil Business Corporate and Consolidated Revenues Product revenues $ 10,135 $ 38,264 $ — $ 48,399 Service revenues 94,663 15,943 — 110,606 Total revenues $ 104,798 $ 54,207 $ — $ 159,005 Operating expenses Operating costs 72,436 53,523 — 125,959 Operating depreciation and amortization 3,424 3,171 — 6,595 Profit (loss) before corporate selling, general, and administrative expenses $ 28,938 $ (2,487 ) $ — $ 26,451 Selling, general, and administrative expenses 23,729 23,729 Depreciation and amortization from SG&A 1,651 1,651 Total selling, general, and administrative expenses $ 25,380 $ 25,380 Other (income) - net (201) (201) Operating income 1,272 Interest expense – net 969 969 Income before income taxes $ 303
Reconciliation of Assets from Segment to Consolidated	Total assets by segment as of June 17, 2017 and December 31, 2016 were as follows: (Thousands) June 17, 2017 December 31, 2016 Total Assets: Environmental Services $ 130,944 $ 129,506 Oil Business 128,596 135,323 Unallocated Corporate Assets 37,929 49,478 Total $ 297,469 $ 314,307

Share-based Compensation (Table

Share-based Compensation (Tables)	6 Months Ended
	Jun. 17, 2017
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 31, 2016 514,287 $ 11.00 1.33 $ 2,414 Exercised (216,253 ) 10.90 — — Options outstanding at June 17, 2017 298,034 $ 11.08 0.85 $ 1,004
Schedule of Restricted Stock Unit Activity	The following table shows a summary of restricted shares grants and expense resulting from the awards: Compensation Expense (thousands except for shares total) First Half Ended, Unrecognized Expense as of Recipient of Grant Grant Date Restricted Shares June 17, 2017 June 18, 2016 June 17, 2017 December 31, 2016 Board of Directors April, 2017 28,674 $ 113 $ 132 $ 134 $ — Members of Management February, 2015 38,732 51 57 59 170 Members of Management January, 2016 43,208 48 55 160 258 Members of Management February, 2017 146,564 200 264 1,183 2,028 Chief Executive Officer February, 2017 500,000 455 — 3,080 — The following table summarizes the restricted stock activity for the period ended June 17, 2017 : Restricted Stock (Nonvested Shares) Number of Shares Weighted Average Grant-Date Fair Value Per Share Nonvested shares outstanding at December 31, 2016 136,171 $ 12.42 Granted 659,842 15.11 Vested (96,636 ) 13.16 Nonvested shares outstanding at June 17, 2017 699,377 $ 14.51
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 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)	6 Months Ended
	Jun. 17, 2017
Earnings Per Share [Abstract]
Schedule of Basic and Diluted Earnings Per Share	The following table reconciles the number of shares outstanding for the second quarters and the first half ended of fiscal 2017 and 2016 , 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: Second Quarter Ended, First Half Ended, (Thousands) June 17, 2017 June 18, 2016 June 17, 2017 June 18, 2016 Net income $ 6,986 $ 1,831 $ 11,803 $ 106 Less: Income attributable to noncontrolling interest 52 — 105 42 Net income attributable to Heritage-Crystal Clean, Inc. available to common stockholders $ 6,934 $ 1,831 $ 11,698 $ 64 Weighted average basic shares outstanding 22,506 22,246 22,430 22,236 Dilutive shares from share–based compensation plans 326 173 299 156 Weighted average diluted shares outstanding 22,832 22,419 22,729 22,392 Net income per share: basic $ 0.31 $ 0.08 $ 0.52 $ — Net income per share: diluted $ 0.30 $ 0.08 $ 0.51 $ —

Summary of Significant Accoun33

Summary of Significant Accounting Policies (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 17, 2017	Dec. 31, 2016	Jan. 02, 2016
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Excess tax benefits from share-based compensation	$ 2,500
Cumulative-effect increase due to adoption of ASU		$ 1,009
Less: unamortized debt issuance costs	1,418	741
Retained Earnings [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative-effect increase due to adoption of ASU		1,009
Accounting Standards Update 2015-03 [Member] | Other Current Assets [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Less: unamortized debt issuance costs			$ (1,400)
Accounting Standards Update 2015-03 [Member] | Term Loan, Less Current Maturities [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Less: unamortized debt issuance costs			$ 1,400
New Accounting Pronouncement, Early Adoption, Effect [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Excess tax benefits from share-based compensation	2,500
New Accounting Pronouncement, Early Adoption, Effect [Member] | Accounting Standards Update 2016-09 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative-effect increase to deferred tax assets	1,000	1,000
New Accounting Pronouncement, Early Adoption, Effect [Member] | Accounting Standards Update 2016-09 [Member] | Retained Earnings [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative-effect increase due to adoption of ASU	$ 1,000	$ 1,000

Business Combinations - Narrati

Business Combinations - Narrative (Details) - USD ($) $ in Thousands	Mar. 24, 2016	Dec. 02, 2016
Recycle Engine Coolant, Inc. [Member]
Business Acquisition [Line Items]
Cash paid for acquisition		$ 700
Cash placed into escrow		$ 100
Phoenix Environmental Services, Inc. [Member]
Business Acquisition [Line Items]
Cash paid for acquisition	$ 2,700
Cash placed into escrow	300
Decrease to accounts receivable	12
Decrease to property, plant, and equipment	77
Increase to goodwill	$ 89

Business Combinations - Assets

Business Combinations - Assets and Liabilities Acquired (Details) - USD ($) $ in Thousands	Jun. 17, 2017	Dec. 31, 2016	Dec. 02, 2016	Mar. 24, 2016	Jan. 02, 2016
Business Acquisition [Line Items]
Goodwill	$ 31,573	$ 31,483			$ 30,325
Phoenix Environmental Services, Inc. [Member]
Business Acquisition [Line Items]
Accounts receivable				$ 260
Inventory				27
Property, plant, & equipment				398
Equipment at customers				38
Intangible assets				700
Goodwill				1,245
Total purchase price, net of cash acquired				$ 2,668
Recycle Engine Coolant, Inc. [Member]
Business Acquisition [Line Items]
Accounts receivable			$ 80
Inventory			56
Property, plant, & equipment			457
Equipment at customers			0
Intangible assets			132
Goodwill			0
Total purchase price, net of cash acquired			$ 725

Accounts Receivable - Component

Accounts Receivable - Components of Accounts Receivable (Details) - USD ($) $ in Thousands	Jun. 17, 2017	Dec. 31, 2016	Jan. 02, 2016
Accounts Receivable, Net [Abstract]
Trade	$ 44,682	$ 42,332
Less: allowance for doubtful accounts	1,843	2,176	$ 2,207
Trade - net	42,839	40,156
Related parties	814	1,324
Other	690	6,053
Total accounts receivable - net	$ 44,343	$ 47,533

Accounts Receivable - Allowance

Accounts Receivable - Allowance for Doubtful Accounts (Details) - USD ($) $ in Thousands	6 Months Ended		12 Months Ended
	Jun. 17, 2017	Jun. 18, 2016	Dec. 31, 2016
Allowance for Doubtful Accounts Receivable [Roll Forward]
Balance at beginning of period	$ 2,176	$ 2,207	$ 2,207
Provision for bad debts	(6)	$ 361	687
Accounts written off, net of recoveries	(327)		(718)
Balance at end of period	$ 1,843		$ 2,176

Inventory (Details)

Inventory (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 17, 2017	Jun. 18, 2016	Jun. 17, 2017	Jun. 18, 2016	Dec. 31, 2016
Inventory Disclosure [Abstract]
Used oil and processed oil	$ 5,815,000		$ 5,815,000		$ 5,493,000
Solvents and solutions	5,692,000		5,692,000		5,014,000
Drums and supplies	3,562,000		3,562,000		3,790,000
Machines	2,517,000		2,517,000		2,576,000
Other	1,639,000		1,639,000		1,899,000
Total inventory	19,225,000		19,225,000		18,772,000
Less: machine refurbishing reserve	363,000		363,000		214,000
Total inventory - net	18,862,000		18,862,000		$ 18,558,000
Inventory write-down	$ 0	$ 200,000	$ 0	$ 1,651,000

Property, Plant, and Equipmen39

Property, Plant, and Equipment (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 17, 2017	Jun. 18, 2016	Jun. 17, 2017	Jun. 18, 2016	Dec. 31, 2016
Property, Plant and Equipment [Abstract]
Machinery, vehicles, and equipment	$ 79,018		$ 79,018		$ 78,592
Buildings and storage tanks	69,136		69,136		69,977
Land	10,366		10,366		10,363
Leasehold improvements	4,946		4,946		4,876
Construction in progress	11,914		11,914		8,646
Assets held for sale	61		61		177
Total property, plant and equipment	175,441		175,441		172,631
Less: accumulated depreciation	(45,901)		(45,901)		(41,456)
Property, plant and equipment - net	129,540		129,540		131,175
Equipment at customers	65,663		65,663		63,502
Less: accumulated depreciation	(42,546)		(42,546)		(40,469)
Equipment at customers - net	23,117		23,117		$ 23,033
Depreciation expense	$ 3,400	$ 3,400	$ 6,800	$ 6,700

Goodwill and Other Intangible40

Goodwill and Other Intangible Assets - Goodwill (Details) $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 17, 2017USD ($)reporting_unit	Dec. 31, 2016USD ($)
Goodwill and Intangible Assets Disclosure [Abstract]
Number of reporting units | reporting_unit	2
Goodwill [Roll Forward]
Gross carrying amount, beginning balance	$ 35,435	$ 34,277
Accumulated impairment loss, beginning balance	(3,952)	(3,952)
Goodwill, beginning balance	31,483	30,325
Acquisitions		1,158
Measurement period adjustments	0
Gross carrying amount, ending balance	35,525	35,435
Accumulated impairment loss, ending balance	(3,952)	(3,952)
Goodwill, ending balance	31,573	31,483
Oil Business Segment [Member]
Goodwill [Roll Forward]
Gross carrying amount, beginning balance	3,952	3,952
Accumulated impairment loss, beginning balance	(3,952)	(3,952)
Goodwill, beginning balance	0	0
Acquisitions		0
Measurement period adjustments	0
Gross carrying amount, ending balance	3,952	3,952
Accumulated impairment loss, ending balance	(3,952)	(3,952)
Goodwill, ending balance	0	0
Environmental Services Segment [Member]
Goodwill [Roll Forward]
Gross carrying amount, beginning balance	31,483	30,325
Accumulated impairment loss, beginning balance	0	0
Goodwill, beginning balance	31,483	30,325
Acquisitions		1,158
Measurement period adjustments	90
Gross carrying amount, ending balance	31,573	31,483
Accumulated impairment loss, ending balance	0	0
Goodwill, ending balance	$ 31,573	$ 31,483

Goodwill and Other Intangible41

Goodwill and Other Intangible Assets - Summary of Intangibles (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 17, 2017	Jun. 18, 2016	Jun. 17, 2017	Jun. 18, 2016	Dec. 31, 2016
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 33,708		$ 33,708		$ 33,669
Accumulated Amortization	15,364		15,364		13,848
Net Carrying Amount	18,344		18,344		19,821
Amortization of intangible assets	800	$ 700	1,500	$ 1,500
Finite-Lived Intangible Assets, Amortization Expense, Maturity Schedule [Abstract]
2,017	1,700		1,700
2,018	3,000		3,000
2,019	2,600		2,600
2,020	2,500		2,500
2,021	2,400		2,400
Customer & supplier relationships [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	23,050		23,050		23,045
Accumulated Amortization	7,763		7,763		6,682
Net Carrying Amount	15,287		$ 15,287		16,363
Useful life			10 years
Software [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	4,604		$ 4,604		4,573
Accumulated Amortization	3,768		3,768		3,655
Net Carrying Amount	836		$ 836		918
Useful life			9 years
Non-compete agreements [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	2,937		$ 2,937		2,934
Accumulated Amortization	2,381		2,381		2,180
Net Carrying Amount	556		$ 556		754
Useful life			5 years
Patents, formulae, and licenses [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	1,769		$ 1,769		1,769
Accumulated Amortization	607		607		576
Net Carrying Amount	1,162		$ 1,162		1,193
Useful life			15 years
Other intangible assets [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	1,348		$ 1,348		1,348
Accumulated Amortization	845		845		755
Net Carrying Amount	$ 503		$ 503		$ 593
Useful life			6 years

Debt and Financing Arrangemen42

Debt and Financing Arrangements - Narrative (Details) - USD ($)	Feb. 21, 2017	Jun. 17, 2017	Jun. 18, 2016	Jun. 17, 2017	Jun. 18, 2016	Dec. 31, 2016
Debt Instrument [Line Items]
Payments of debt issuance costs				$ 1,050,000	$ 0
Less: unamortized debt issuance costs		$ 1,418,000		$ 1,418,000		$ 741,000
Interest costs capitalized, less than $0.1 million for the second quarter and first half of 2016			$ 100,000		$ 100,000
Weighted average interest rate		3.80%	3.80%	3.80%	3.80%
Letters of credit outstanding		$ 2,400,000		$ 2,400,000		3,000,000
Current borrowing capacity		62,600,000		62,600,000		$ 27,600,000
Term Loan [Member]
Debt Instrument [Line Items]
Interest costs incurred		400,000		900,000
New Credit Agreement [Member]
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		1,100,000
New Credit Agreement [Member] | Line of Credit [Member]
Debt Instrument [Line Items]
Maximum borrowing capacity	$ 95,000,000
New Credit Agreement [Member] | Line of Credit [Member] | Federal Funds Effective Swap Rate [Member]
Debt Instrument [Line Items]
Basis spread on variable rate	0.50%
New Credit Agreement [Member] | Line of Credit [Member] | London Interbank Offered Rate (LIBOR) [Member]
Debt Instrument [Line Items]
Basis spread on variable rate	1.00%
New Credit Agreement [Member] | Line of Credit [Member] | London Interbank Offered Rate (LIBOR) [Member] | Minimum [Member]
Debt Instrument [Line Items]
Basis spread on variable rate	1.75%
New Credit Agreement [Member] | Line of Credit [Member] | London Interbank Offered Rate (LIBOR) [Member] | Maximum [Member]
Debt Instrument [Line Items]
Basis spread on variable rate	2.75%
New Credit Agreement [Member] | Line of Credit [Member] | Prime Rate [Member] | Minimum [Member]
Debt Instrument [Line Items]
Basis spread on variable rate	0.75%
New Credit Agreement [Member] | Line of Credit [Member] | Prime Rate [Member] | Maximum [Member]
Debt Instrument [Line Items]
Basis spread on variable rate	1.75%
New Credit Agreement [Member] | Term Loan [Member]
Debt Instrument [Line Items]
Maximum borrowing capacity	$ 30,000,000
Effective interest rate	3.28%
New Credit Agreement [Member] | Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Maximum borrowing capacity	$ 65,000,000
Prior Credit Agreement [Member] | Selling, General and Administrative Expenses [Member]
Debt Instrument [Line Items]
Less: unamortized debt issuance costs		$ 200,000		$ 200,000
Prior Credit Agreement [Member] | Term Loan [Member]
Debt Instrument [Line Items]
Interest costs incurred			$ 500,000		$ 1,000,000

Debt and Financing Arrangemen43

Debt and Financing Arrangements - Summary of Debt (Details) - USD ($) $ in Thousands	Jun. 17, 2017	Dec. 31, 2016
Debt Disclosure [Abstract]
Principal amount	$ 30,000	$ 64,195
Less: unamortized debt issuance costs	1,418	741
Debt less unamortized debt issuance costs	$ 28,582	$ 63,454

Segment Information - Operating

Segment Information - Operating Segment Results (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 17, 2017USD ($)	Jun. 18, 2016USD ($)	Jun. 17, 2017USD ($)segment	Jun. 18, 2016USD ($)
Segment Reporting [Abstract]
Number of reportable segments | segment			2
Revenues
Product revenues	$ 31,832	$ 24,695	$ 58,812	$ 48,399
Service revenues	54,550	55,857	108,023	110,606
Total revenues	86,382	80,552	166,835	159,005
Operating expenses
Operating costs	63,270	61,711	124,560	125,959
Operating depreciation and amortization	3,336	3,301	6,617	6,595
Profit before corporate selling, general, and administrative expenses	19,776	15,540	35,658	26,451
Selling, general, and administrative expenses	10,575	11,521	22,916	23,729
Depreciation and amortization from SG&A	848	817	1,699	1,651
Total selling, general, and administrative expenses	11,423	12,338	24,615	25,380
Other (income) - net	(3,027)	(142)	(8,033)	(201)
Operating income	11,380	3,344	19,076	1,272
Interest expense – net	412	451	499	969
Income before income taxes	10,968	2,893	18,577	303
Corporate and Eliminations [Member]
Revenues
Product revenues	0	0		0
Service revenues	0	0		0
Total revenues	0	0	0	0
Operating expenses
Operating costs	0	0	0	0
Operating depreciation and amortization	0	0	0	0
Profit before corporate selling, general, and administrative expenses	0	0	0	0
Selling, general, and administrative expenses	10,575	11,521	22,916	23,729
Depreciation and amortization from SG&A	848	817	1,699	1,651
Total selling, general, and administrative expenses	11,423	12,338	24,615	25,380
Other (income) - net	(3,027)	(142)	(8,033)	(201)
Interest expense – net	412	451	499	969
Environmental Services Segment [Member] | Operating Segments [Member]
Revenues
Product revenues	5,868	5,106	11,592	10,135
Service revenues	49,225	47,331	96,716	94,663
Total revenues	55,093	52,437	108,308	104,798
Operating expenses
Operating costs	36,601	35,631	73,121	72,436
Operating depreciation and amortization	1,801	1,710	3,547	3,424
Profit before corporate selling, general, and administrative expenses	16,691	15,096	31,640	28,938
Oil Business Segment [Member] | Operating Segments [Member]
Revenues
Product revenues	25,964	19,589	47,220	38,264
Service revenues	5,325	8,526	11,307	15,943
Total revenues	31,289	28,115	58,527	54,207
Operating expenses
Operating costs	26,669	26,080	51,439	53,523
Operating depreciation and amortization	1,535	1,591	3,070	3,171
Profit before corporate selling, general, and administrative expenses	$ 3,085	$ 444	$ 4,018	$ (2,487)

Segment Information - Assets by

Segment Information - Assets by Segment (Details) - USD ($) $ in Thousands	Jun. 17, 2017	Dec. 31, 2016
Segment Reporting Information [Line Items]
Assets	$ 297,469	$ 314,307
Unallocated Corporate Assets [Member]
Segment Reporting Information [Line Items]
Assets	37,929	49,478
Environmental Services Segment [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Assets	130,944	129,506
Oil Business Segment [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Assets	$ 128,596	$ 135,323

Commitments and Contingencies (

Commitments and Contingencies (Details) - USD ($) $ in Millions	Jun. 17, 2017	Dec. 31, 2016
Commitments and Contingencies Disclosure [Abstract]
Remaining amount committed	$ 16.7	$ 9.7
Loss contingency accrual	$ 5.6	$ 5.5

Income Taxes (Details)

Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 17, 2017	Jun. 18, 2016	Jun. 17, 2017	Jun. 18, 2016	Dec. 31, 2016	Dec. 31, 2011
Income Tax Disclosure [Abstract]
Net operating loss	$ 32,900		$ 32,900			$ 44,700
Gross deferred tax asset	$ 12,500		12,500
Excess tax benefits from share-based compensation			$ 2,500
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative-effect increase due to adoption of ASU					$ 1,009
Effective tax rate	36.30%	36.70%	36.50%	65.00%
Reserve balance	$ 2,400		$ 2,400		2,400
Retained Earnings [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative-effect increase due to adoption of ASU					1,009
New Accounting Pronouncement, Early Adoption, Effect [Member]
Income Tax Disclosure [Abstract]
Excess tax benefits from share-based compensation			2,500
Accounting Standards Update 2016-09 [Member] | New Accounting Pronouncement, Early Adoption, Effect [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative-effect increase to deferred tax assets	1,000		1,000		1,000
Accounting Standards Update 2016-09 [Member] | New Accounting Pronouncement, Early Adoption, Effect [Member] | Retained Earnings [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative-effect increase due to adoption of ASU	$ 1,000		$ 1,000		$ 1,000

Share-based Compensation - Stoc

Share-based Compensation - Stock Options (Details) - USD ($) $ / shares in Units, $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 17, 2017	Dec. 31, 2016
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Number of shares authorized	1,902,077
Number of shares available for grant	725,361
Number of Options Outstanding
Options outstanding at Beginning of Period (in shares)	514,287
Exercised (in shares)	(216,253)
Options outstanding at End of Period (in shares)	298,034	514,287
Weighted Average Exercise Price
Options outstanding at Beginning of Period (in dollars per share)	$ 11
Exercised (in dollars per share)	10.90
Options outstanding at End of Period (in dollars per share)	$ 11.08	$ 11
Weighted Average Remaining Contractual Term and Aggregate Intrinsic Value as of Date Listed
Weighted average remaining contractual term (in years)	10 months 6 days	1 year 3 months 29 days
Aggregate intrinsic value as of date listed	$ 1,004	$ 2,414

Share-based Compensation - Rest

Share-based Compensation - Restricted Stock Compensation/Awards (Details) - USD ($) $ / shares in Units, $ in Thousands	Apr. 30, 2017	Feb. 28, 2017	Jan. 31, 2016	Feb. 28, 2015	Jun. 17, 2017	Jun. 18, 2016	Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted shares granted (in shares)					659,842
Mr. Recatto [Member]
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 [Member] | Board of Directors [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period (in years)					1 year
Restricted Stock [Member] | Board of Directors [Member] | 2017 Board of Directors Grant [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted shares granted (in shares)	28,674
Compensation expense					$ 113	$ 132
Unrecognized compensation expense					$ 134		$ 0
Restricted Stock [Member] | Members of Management [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period (in years)					3 years
Restricted Stock [Member] | Members of Management [Member] | February 2015 Grant [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted shares granted (in shares)				38,732
Compensation expense					$ 51	57
Unrecognized compensation expense					59		170
Restricted Stock [Member] | Members of Management [Member] | January 2016 Grant [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted shares granted (in shares)			43,208
Compensation expense					48	55
Unrecognized compensation expense					160		258
Restricted Stock [Member] | Members of Management [Member] | February 2017 Grant [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted shares granted (in shares)		146,564
Compensation expense					200	264
Unrecognized compensation expense					1,183		2,028
Restricted Stock [Member] | Chief Executive Officer [Member] | February 2017 CEO Grant [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted shares granted (in shares)		500,000
Compensation expense					455	$ 0
Unrecognized compensation expense					3,080		$ 0
Restricted Stock [Member] | Mr. Recatto [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense					$ 500
Unrecognized compensation expense		$ 3,100
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 [Member] | Mr. Recatto [Member] | From Employment Commencement Date to Vesting Date [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period (in years)					180 days
Vesting percentage		0.00%			50.00%

Share-based Compensation - Re50

Share-based Compensation - Restricted Stock Vesting Schedule by Percentage (Details) - Mr. Recatto [Member] - Restricted Stock [Member] - $ / shares	1 Months Ended	6 Months Ended
	Feb. 28, 2017	Jun. 17, 2017
Less than $5 per share increase [Member]
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	0.00%	50.00%
$5 per share increase [Member]
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	25.00%
$10 per share increase [Member]
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	50.00%
$15 per share increase [Member]
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	75.00%
$20 or more per share increase [Member]
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	100.00%

Share-based Compensation - Nonv

Share-based Compensation - Nonvested Restricted Stock (Details)	6 Months Ended
	Jun. 17, 2017$ / sharesshares
Number of Shares
Nonvested shares outstanding at Beginning of Period (in shares) | shares	136,171
Granted (in shares) | shares	659,842
Vested (in shares) | shares	(96,636)
Nonvested shares outstanding at End of Period (in shares) | shares	699,377
Weighted Average Grant-Date Fair Value Per Share
Nonvested shares outstanding at Beginning of Period (in dollars per share) | $ / shares	$ 12.42
Granted (in dollars per share) | $ / shares	15.11
Vested (in dollars per share) | $ / shares	13.16
Nonvested shares outstanding at End of Period (in dollars per share) | $ / shares	$ 14.51

Share-based Compensation - Empl

Share-based Compensation - Employee Stock Purchase Plan (Details)	6 Months Ended
	Jun. 17, 2017$ / sharesshares
Common Stock [Member]
Employee Stock Ownership Plan (ESOP) Disclosures [Line Items]
Issuance of common stock – ESPP (in shares)	14,367
Employee Stock Purchase Plan of 2008 [Member] | Employee Stock [Member]
Employee Stock Ownership Plan (ESOP) Disclosures [Line Items]
Shares available employee stock purchase plan (in shares)	161,812
Weighted average fair value per share ESPP (in dollars per share) | $ / shares	$ 14.44

Earnings Per Share (Details)

Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 17, 2017	Jun. 18, 2016	Jun. 17, 2017	Jun. 18, 2016
Earnings Per Share [Abstract]
Net income	$ 6,986	$ 1,831	$ 11,803	$ 106
Less: Income attributable to noncontrolling interest	52	0	105	42
Net income attributable to Heritage-Crystal Clean, Inc. common stockholders	$ 6,934	$ 1,831	$ 11,698	$ 64
Weighted average basic shares outstanding (in shares)	22,506	22,246	22,430	22,236
Dilutive shares from share–based compensation plans (in shares)	326	173	299	156
Weighted average diluted shares outstanding (in shares)	22,832	22,419	22,729	22,392
Net income per share: basic (in dollars per share)	$ 0.31	$ 0.08	$ 0.52	$ 0
Net income per share: diluted (in dollars per share)	$ 0.30	$ 0.08	$ 0.51	$ 0

Other Expense (Income) (Details

Other Expense (Income) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 17, 2017	Jun. 18, 2016	Jun. 17, 2017	Jun. 18, 2016
Loss Contingencies [Line Items]
Other income	$ 3,027	$ 142	$ 8,033	$ 201
FCC Environmental Arbitration [Member]
Loss Contingencies [Line Items]
Other income	$ 3,600		$ 5,100

Subsequent Events (Details)

Subsequent Events (Details) $ in Millions	3 Months Ended
	Sep. 09, 2017USD ($)
Chief Operating Officer [Member] | Scenario, Forecast [Member]
Subsequent Event [Line Items]
Severance charges	$ 1.2