Archrock Partners (APLP) 10-Q 1 Nov 18 2018 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2018	Oct. 25, 2018
Document and Entity Information
Entity Registrant Name	Archrock Partners, L.P.
Entity Central Index Key	1,367,064
Document Type	10-Q
Document Period End Date	Sep. 30, 2018
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Entity Current Reporting Status	Yes
Entity Filer Category	Accelerated Filer
Entity Common Stock, Shares Outstanding		70,231,036
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	Q3
Entity Emerging Growth Company	false
Entity Small Business	false

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Current assets:
Cash	$ 243	$ 8,078
Accounts receivable, trade, net of allowance of $946 and $1,296, respectively	73,258	67,714
Current portion of interest rate swaps	3,592	186
Accrued interest on loan receivable due from Archrock	217	0
Total current assets	77,310	75,978
Property, plant and equipment	2,872,151	2,727,401
Accumulated depreciation	(994,422)	(953,325)
Property, plant and equipment, net	1,877,729	1,774,076
Intangible assets, net	49,359	60,747
Contract costs	29,531	0
Loan receivable due from Archrock	53,500	0
Other long-term assets	24,216	19,401
Total assets	2,111,645	1,930,202
Current liabilities:
Accounts payable, trade	21,831	18,368
Accrued liabilities	10,489	7,597
Deferred revenue	9,881	1,299
Accrued interest	23,163	12,972
Due to Archrock, net	3,349	4,683
Current portion of interest rate swaps	0	134
Total current liabilities	68,713	45,053
Long-term debt	1,515,679	1,361,053
Other long-term liabilities	9,529	9,356
Total liabilities	1,593,921	1,415,462
Commitments and contingencies (Note 13)
Partners’ capital:
Common units: 70,231,036 and 70,310,590 issued, respectively	493,197	501,023
General partner units: 1,422,458 and 1,421,768 issued and outstanding, respectively	11,448	11,582
Accumulated other comprehensive income	13,079	4,476
Treasury units: 113,609 common units at December 31, 2017	0	(2,341)
Total partners’ capital	517,724	514,740
Total liabilities and partners’ capital	$ 2,111,645	$ 1,930,202

CONDENSED CONSOLIDATED BALANC_2

CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Statement of Financial Position [Abstract]
Accounts receivable, trade, allowance (in dollars)	$ 946	$ 1,296
Common units, units issued (in units)	70,231,036	70,310,590
General partner units, equivalent units issued (in units)	1,422,458	1,421,768
General partner units, equivalent units outstanding (in units)	1,422,458	1,421,768
Treasury units, common units (in units)		113,609

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Income Statement [Abstract]
Revenue	$ 154,033	$ 140,191	$ 451,901	$ 415,741
Cost of sales (excluding depreciation and amortization)	62,068	62,584	178,596	172,856
Selling, general and administrative	18,143	20,711	57,288	59,325
Depreciation and amortization	34,095	35,787	102,319	108,947
Long-lived asset impairment	3,673	5,368	10,585	14,659
Interest expense, net	22,767	21,839	66,918	63,361
Debt extinguishment loss	0	0	0	291
Merger-related costs	2	0	2,718	0
Other (income) loss, net	126	(2,793)	(555)	(3,614)
Income (loss) before income taxes	13,159	(3,305)	34,032	(84)
Provision for income taxes	546	708	648	2,970
Net income (loss)	$ 12,613	$ (4,013)	$ 33,384	$ (3,054)

CONDENSED CONSOLIDATED STATEM_2

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ 12,613	$ (4,013)	$ 33,384	$ (3,054)
Other comprehensive income:
Interest rate swap gain, net of reclassifications to earnings	1,213	2,314	8,376	4,452
Amortization of terminated interest rate swaps	0	257	227	257
Total other comprehensive income	1,213	2,571	8,603	4,709
Comprehensive income (loss)	$ 13,826	$ (1,442)	$ 41,987	$ 1,655

CONDENSED CONSOLIDATED STATEM_3

CONDENSED CONSOLIDATED STATEMENTS OF PARTNERS' CAPITAL - USD ($) $ in Thousands	Total	Treasury Units	Accumulated Other Comprehensive Income (Loss)	Partners' Capital Common Units	Partners' Capital General Partner Units
Beginning balance at Dec. 31, 2016	$ 522,173	$ (1,892)	$ (4,170)	$ 516,208	$ 12,027
Beginning balance (in units) at Dec. 31, 2016		(86,795)		65,606,655	1,326,965
Increase (Decrease) in Partners' Capital
Issuance of common units for vesting of phantom units (in units)				89,263
Treasury units purchased	(404)	$ (404)
Treasury units purchased (in units)		(22,977)
Issuance of common units				$ 60,291	$ 60,291
Issuance of common units (in units)				4,600,000
Issuance of general partner units					$ 1,305
Issuance of general partner units (in units)					94,506
Contribution (distribution) of capital, net	1,706			$ 1,798	$ (92)
Cash distributions	(58,690)			(57,528)	(1,162)
Unit-based compensation expense	753			753
Comprehensive income
Net income (loss)	(3,054)			(2,991)	(63)
Interest rate swap gain, net of reclassifications to earnings	4,452		4,452
Amortization of terminated interest rate swaps	257		257
Ending balance at Sep. 30, 2017	528,789	$ (2,296)	539	$ 518,531	$ 12,015
Ending balance (in units) at Sep. 30, 2017		(109,772)		70,295,918	1,421,471
Increase (Decrease) in Partners' Capital
Cumulative effect of adoption of new accounting principle | ASU 2014-09	12,714			$ 12,462	$ 252
Cumulative effect of adoption of new accounting principle | ASU 2017-12	383			375	8
Beginning balance at Dec. 31, 2017	514,740	$ (2,341)	4,476	$ 501,023	$ 11,582
Beginning balance (in units) at Dec. 31, 2017		(113,609)		70,310,590	1,421,768
Increase (Decrease) in Partners' Capital
Issuance of common units for vesting of phantom units (in units)				53,091
Treasury units purchased	(250)	$ (250)
Treasury units purchased (in units)		(19,036)
Issuance of general partner units	9				$ 9
Issuance of general partner units (in units)					690
Contribution (distribution) of capital, net	1,544			$ 1,544
Cash distributions	(53,717)			(52,651)	$ (1,066)
Unit-based compensation expense	314			314
Merger-related adjustments		$ 2,591		$ (2,591)
Merger-related adjustments (in units)		132,645		(132,645)
Comprehensive income
Net income (loss)	33,384			$ 32,721	663
Interest rate swap gain, net of reclassifications to earnings	8,376		8,376
Amortization of terminated interest rate swaps	227		227
Ending balance at Sep. 30, 2018	$ 517,724	$ 0	$ 13,079	$ 493,197	$ 11,448
Ending balance (in units) at Sep. 30, 2018		0		70,231,036	1,422,458

CONDENSED CONSOLIDATED STATEM_4

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Cash flows from operating activities:
Net income (loss)	$ 33,384	$ (3,054)
Adjustments to reconcile net income (loss) to cash provided by operating activities:
Depreciation and amortization	102,319	108,947
Long-lived asset impairment	10,585	14,659
Amortization of deferred financing costs	4,371	4,320
Amortization of debt discount	1,049	986
Amortization of terminated interest rate swaps	227	257
Debt extinguishment loss	0	291
Interest rate swaps	166	2,028
Unit-based compensation expense	314	753
Provision for doubtful accounts	773	2,287
Gain on sale of property, plant and equipment	(621)	(3,518)
Deferred income tax provision	294	2,918
Amortization of contract costs	7,962	0
Non-cash deferred revenue	(9,326)	0
Changes in assets and liabilities:
Accounts receivable, trade	(5,881)	(10,255)
Contract costs	(21,176)	0
Deferred revenue	14,010	(72)
Other assets and liabilities	13,810	16,625
Net cash provided by operating activities	152,260	137,172
Cash flows from investing activities:
Capital expenditures	(217,692)	(115,939)
Proceeds from sale of property, plant and equipment	17,336	17,316
Proceeds from insurance	252	0
Loan receivable due from Archrock	(53,500)	0
Net cash used in investing activities	(253,604)	(98,623)
Cash flows from financing activities:
Proceeds from borrowings of long-term debt	425,830	818,500
Repayments of long-term debt	(273,636)	(846,500)
Payments for debt issuance costs	(3,332)	(14,855)
Payments for settlement of interest rate swaps that include financing elements	(61)	(1,405)
Distributions to unitholders	(53,717)	(58,690)
Net proceeds from issuance of common units	0	60,291
Net proceeds from sale of general partner units	9	1,305
Purchases of treasury units	(250)	(404)
Increase (decrease) in amounts due to Archrock, net	(1,334)	3,440
Net cash provided by (used in) financing activities	93,509	(38,318)
Net increase (decrease) in cash	(7,835)	231
Cash at beginning of period	8,078	217
Cash at end of period	243	448
Supplemental disclosure of non-cash transactions:
Non-cash capital contribution, net from limited and general partner	1,544	3,855
Contract operations equipment acquired/exchanged, net	$ 0	$ (2,149)

Organization and Basis of Prese

Organization and Basis of Presentation	9 Months Ended
	Sep. 30, 2018
Accounting Policies [Abstract]
Organization and Basis of Presentation	1. Organization and Basis of Presentation We are a Delaware limited partnership formed in June 2006 to provide natural gas contract operations services to customers throughout the U.S. Our contract operations services primarily include designing, sourcing, owning, installing, operating, servicing, repairing and maintaining equipment to provide natural gas compression services to our customers. The accompanying unaudited condensed consolidated financial statements included herein have been prepared in accordance with U.S. GAAP for interim financial information and the rules and regulations of the SEC. Certain information and footnote disclosures normally included in financial statements prepared in accordance with GAAP are not required in these interim financial statements and have been condensed or omitted. Management believes that the information furnished includes all adjustments, consisting only of normal recurring adjustments, which are necessary to present fairly our consolidated financial position, results of operations and cash flows for the periods indicated. The accompanying unaudited condensed consolidated financial statements should be read in conjunction with the consolidated financial statements presented in our 2017 Form 10-K, which contains a more comprehensive summary of our accounting policies. The interim results reported herein are not necessarily indicative of results for a full year. Certain prior year amounts have been reclassified to conform to the current year presentation. We meet the conditions specified in General Instruction H(1)(a) and (b) of Form 10-Q and are thereby permitted to use the reduced disclosure format for wholly-owned subsidiaries of reporting companies specified therein. Accordingly, we have omitted from this report the information called for by Part I Item 3 “Quantitative and Qualitative Disclosures About Market Risk,” Part II Item 2 “Unregistered Sales of Equity Securities” and Part II Item 3 “Defaults Upon Senior Securities.” In addition, in lieu of the information called for by Part I Item 2 “Management’s Discussion and Analysis of Financial Condition and Results of Operations,” we have included, under Item 2, “Management’s Narrative Analysis of Results of Operations” to explain the reasons for material changes in the amount of revenue and expense items between the periods reported herein.

Recent Accounting Developments

Recent Accounting Developments	9 Months Ended
	Sep. 30, 2018
New Accounting Pronouncements and Changes in Accounting Principles [Abstract]
Recent Accounting Developments	2. Recent Accounting Developments Accounting Standards Updates Implemented On January 1, 2018, we adopted ASU 2017-12 using the modified retrospective approach to existing cash flow hedge relationships as of January 1, 2018. ASU 2017-12 expands and refines hedge accounting for both financial and nonfinancial risk components, aligns the recognition and presentation of the effects of the hedging instrument and hedged item in the financial statements and eliminates the requirement to separately measure and report hedge ineffectiveness. As a result of the adoption of ASU 2017-12, we recognized a net gain of $0.4 million as a cumulative-effect adjustment to opening partners’ capital and a corresponding adjustment to other comprehensive income (loss) to reverse the cumulative ineffectiveness previously recognized in interest expense. On January 1, 2018, we adopted ASU 2016-15 on a retrospective basis. ASU 2016-15 addresses diversity in practice and simplifies several elements of cash flow classification including how certain cash receipts and cash payments are classified in the statement of cash flows. ASU 2016-15 did not have an impact on our condensed consolidated statement of cash flow for the nine months ended September 30, 2017 . Revenue Recognition Update On January 1, 2018, we adopted the Revenue Recognition Update using the modified retrospective method applied to those contracts which were not completed as of January 1, 2018. We recognized the cumulative effect of initially applying the Revenue Recognition Update as an adjustment to the opening balance of retained earnings. For contracts that were modified before the effective date, we identified performance obligations on the basis of the current version of the contract, which included any contract modifications since inception. The application of the practical expedient for contract modifications did not have a material effect on the adjustment to retained earnings. The comparative information has not been restated and continues to be reported under the accounting standards in effect for those periods. Under previous guidance, contract operations revenue was recognized when earned, which generally occurs monthly when the service is provided under our customer contracts. Under the Revenue Recognition Update the timing of revenue recognition is impacted by contractual provisions for service availability guarantees of our compressor assets and re-billable costs associated with moving our compressor assets to a customer site. These changes are further discussed below and did not result in a material difference from previous practice for contract operations. The Revenue Recognition Update provides guidance on contract costs that should be recognized as assets and amortized over the period that the related goods or services transfer to the customer. Certain costs that were previously expensed as incurred, such as sales commissions and freight charges to transport compressor assets, are deferred and amortized. The following table summarizes the cumulative impact of the adoption of the Revenue Recognition Update on the opening balance sheet (in thousands): December 31, 2017 Adjustments Due to the Revenue Recognition Update January 1, 2018 Assets Contract costs $ — $ 16,316 $ 16,316 Liabilities Accrued liabilities $ 7,597 $ 186 $ 7,783 Deferred revenue 1,299 3,416 4,715 Partners ’ capital Common units $ 501,023 $ 12,462 $ 513,485 General partner units 11,582 252 11,834 The following tables summarize the impact of the application of the Revenue Recognition Update on our condensed consolidated balance sheet and condensed consolidated statement of operations (in thousands): September 30, 2018 Balance Sheet As Reported Balance Excluding the Impact of the Revenue Recognition Update Effect of Change Assets Accounts receivable, trade $ 73,258 $ 72,902 $ 356 Contract costs 29,531 — 29,531 Liabilities Accrued liabilities $ 10,489 $ 10,256 $ 233 Deferred revenue 9,881 2,137 7,744 Other long-term liabilities 9,529 9,534 (5 ) Equity Common units $ 493,197 $ 471,779 $ 21,418 General partner units 11,448 10,951 497 Three Months Ended September 30, 2018 Statement of Operations As Reported Balance Excluding the Impact of the Revenue Recognition Update Effect of Change Revenue $ 154,033 $ 155,377 $ (1,344 ) Cost of sales (excluding depreciation and amortization) 62,068 66,388 (4,320 ) Selling, general and administrative 18,143 18,693 (550 ) Provision for income taxes 546 539 7 Net income 12,613 9,094 3,519 Nine Months Ended September 30, 2018 Statement of Operations As Reported Balance Excluding the Impact of the Revenue Recognition Update Effect of Change Revenue $ 451,901 $ 455,920 $ (4,019 ) Cost of sales (excluding depreciation and amortization) 178,596 190,425 (11,829 ) Selling, general and administrative 57,288 58,674 (1,386 ) Provision for income taxes 648 653 (5 ) Net income 33,384 24,183 9,201 Accounting Standards Updates Not Yet Implemented In August 2018, the FASB issued ASU 2018-13 which amends the required fair value measurements disclosures related to valuation techniques and inputs used, uncertainty in measurement, and changes in measurements applied. These amendments are effective for all entities for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2019. Early adoption is permitted. We are currently evaluating the impact of ASU 2018-13 on our consolidated financial statements and footnote disclosures. In June 2016, the FASB issued ASU 2016-13 that changes the impairment model for most financial assets and certain other instruments, including trade and other receivables, held-to-maturity debt securities and loans, and requires entities to use a new forward-looking expected loss model that will result in the earlier recognition of allowance for losses. For public entities that meet the definition of an SEC filer, ASU 2016-13 is effective for fiscal years beginning after December 15, 2019 and early adoption is permitted. Entities will apply ASU 2016-13 provisions as a cumulative-effect adjustment to retained earnings as of the beginning of the first reporting period in which the guidance is adopted. We are currently evaluating the impact of ASU 2016-13 on our consolidated financial statements and footnote disclosures. Leases ASC Topic 842 Leases establishes a ROU model that requires a lessee to record a ROU asset and a lease liability on the balance sheet for all leases with terms longer than 12 months. Leases will be classified as either finance or operating, with classification affecting the pattern of expense recognition in the income statement. Under the new guidance, lessor accounting is largely unchanged. ASC Topic 842 Leases is effective for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. A modified retrospective transition approach that involves recasting the comparative periods in the year of initial application is required for leases existing at, or entered into after, the beginning of the earliest comparative period presented in the financial statements, with certain transition practical expedients available. In July 2018 the FASB provided an optional transition method that would allow adoption of the standard as of the effective date without restating prior periods. We intend to adopt ASC Topic 842 Leases on January 1, 2019 using the optional transition method and are currently assessing the transition practical expedients. Upon adoption, we will recognize the cumulative effect of adoption as an adjustment to the opening balance of our retained earnings. Comparative information will continue to be reported under the accounting standards in effect for those periods. Additionally, the July 2018 amendment provided lessors with a practical expedient to not separate nonlease components from the associated lease component and, instead, to account for those components as a single component if the nonlease components otherwise would be accounted for under the Revenue Recognition Update and certain conditions are met. The amendment also provided clarification on whether ASC Topic 842 or the Revenue Recognition Update is applicable to the combined component based on determination of the predominant component. An entity that elects the lessor practical expedient also should provide certain disclosures. We are evaluating the impact of the July 2018 amendment on our contract operations services agreements and have tentatively concluded that the services nonlease component is predominant, which would result in the ongoing recognition following the Revenue Recognition Update guidance. Our evaluation of the impact of adopting ASC Topic 842 Leases is ongoing. We have established a cross-functional implementation team to identify our lease population and are assessing changes to our internal control structure, business processes, systems and accounting policies that are necessary to implement the standard. We do not believe the standard will materially affect our consolidated balance sheets, statements of operations or cash flows.

Revenue from Contracts with Cus

Revenue from Contracts with Customers	9 Months Ended
	Sep. 30, 2018
Revenue from Contract with Customer [Abstract]
Revenue from Contracts with Customers	3. Revenue from Contracts with Customers Revenue Recognition Revenue is recognized when control of the promised goods or services is transferred to our customers, in an amount that reflects the consideration we are entitled to receive in exchange for those goods or services. Sales and usage-based taxes that are collected from the customer are excluded from revenue. The following table presents our revenue from contracts with customers disaggregated by revenue source (in thousands): Three Months Ended September 30, 2018 Nine Months Ended September 30, 2018 0 - 1,000 horsepower per unit $ 55,215 $ 164,031 1,001 - 1,500 horsepower per unit 63,806 187,890 Over 1,500 horsepower per unit 34,156 98,056 Other (1) 856 1,924 Total revenue (2) $ 154,033 $ 451,901 —————— (1) Primarily relates to fees associated with Partnership-owned non-compressor equipment. (2) Includes $1.4 million and $3.9 million for three and nine months ended September 30, 2018 , respectively, related to billable maintenance on Partnership-owned units that was recognized at a point in time. All other revenue is recognized over time. Contract Operations We provide comprehensive contract operations services, including the personnel, equipment, tools, materials and supplies to meet our customers’ natural gas compression needs. Based on the operating specifications at the customer location and each customer's unique needs, these services include designing, sourcing, owning, installing, operating, servicing, repairing and maintaining equipment to provide natural gas compression services to our customers. Natural gas compression services are generally satisfied over time, as the customer simultaneously receives and consumes the benefits provided by these services. Our performance obligation is a series in which the unit of service is one month, as the customer receives substantially the same benefit each month from the services regardless of the type of service activity performed, which may vary. If the transaction price is based on a fixed fee, revenue is recognized monthly on a straight-line basis over the period that we are providing services to the customer. Amounts invoiced to customers for costs associated with moving our compressor assets to a customer site are also included in the transaction price and are amortized over the initial contract term. Variable consideration exists if customers are billed at a lesser standby rate when a unit is not running. We have elected to apply the invoicing practical expedient to recognize revenue for such variable consideration, as the invoice corresponds directly to the value transferred to the customer based on our performance completed to date. The rate for standby service is lower to reflect the decrease in costs and effort required to provide standby service when a unit is not running. We also perform billable maintenance service on our natural gas compression equipment at the customer’s request on an as-needed basis. The performance obligation is satisfied and revenue is recognized at the agreed-upon transaction price at the point in time when service is complete and the customer has accepted the work performed and can obtain the remaining benefits of the service that the unit will provide. As of September 30, 2018 , we had $249.7 million of remaining performance obligations related to our contract compression service. We have elected the practical expedient to not consider the effects of the time value of money, as the expected time between the transfer of services and payment for such services is less than one year. This amount will be recognized through 2022 as follows (in thousands): 2018 2019 2020 2021 2022 Total Remaining performance obligations $ 85,439 $ 110,145 $ 44,906 $ 8,132 $ 1,073 $ 249,695 Contract Balances Contract operations services are generally billed monthly at the beginning of the month in which service is being provided. We recognize a contract asset when we have the right to consideration in exchange for goods or services transferred to a customer when the right is conditioned on something other than the passage of time. We recognize a contract liability when we have an obligation to transfer goods or services to a customer for which we have already received consideration. Freight billings to transport compressor assets often result in a contract liability. As of September 30, and January 1, 2018 , our receivables from contracts with customers, net of allowance for doubtful accounts were $71.9 million and $66.2 million , respectively. As of September 30, and January 1, 2018 , our contract liabilities were $10.1 million and $5.4 million , respectively, which are included in deferred revenue and other long-term liabilities in our condensed consolidated balance sheets. The increase in the contract liability balance during the nine months ended September 30, 2018 was due to the deferral of $14.0 million partially offset by $9.3 million recognized as revenue during the period, each primarily related to freight billings. 5. Contract Costs We capitalize incremental costs to obtain a contract with a customer if we expect to recover those costs. Capitalized costs include commissions paid to our sales force to obtain contract operations contracts. As of September 30 , and January 1, 2018, we recorded contract costs of $3.3 million and $2.0 million , respectively, associated with sales commissions. We capitalize costs incurred to fulfill a contract if those costs relate directly to a contract, enhance resources that we will use in satisfying performance obligations and if we expect to recover those costs. Capitalized costs incurred to fulfill our customer contracts include freight charges to transport compressor assets before transferring services to the customer and mobilization activities associated with our contract operations services. As of September 30 , and January 1, 2018, we recorded contract costs of $26.2 million and $14.3 million , respectively, associated with freight and mobilization. Contract operations costs are amortized based on the transfer of service to which the assets relate, which is estimated to be 36 months based on average contract term, including anticipated renewals. We assess periodically whether the 36 -month estimate fairly represents the average contract term and adjust as appropriate. Contract costs associated with commissions are amortized to SG&A. Contract costs associated with freight and mobilization are amortized to cost of sales (excluding depreciation and amortization). During the three and nine months ended September 30, 2018 , we amortized $0.4 million and $0.9 million , respectively, related to commissions and $2.8 million and $7.1 million , respectively, related to freight and mobilization. During the three and nine months ended September 30, 2018 , there were no impairment losses recorded in relation to the costs capitalized.

Related Party Transactions

Related Party Transactions	9 Months Ended
	Sep. 30, 2018
Related Party Transactions [Abstract]
Related Party Transactions	4. Related Party Transactions Revolving Loan Agreement with Archrock In conjunction with the closing of the Merger on April 26, 2018, we and Archrock entered into the Revolving Loan Agreement under which we may make loans to Archrock from time to time in an aggregate amount not to exceed the Credit Facility’s outstanding balance. The Revolving Loan Agreement matures on the maturity date of our Credit Facility. Interest on amounts loaned under the Revolving Loan Agreement is payable to us on a monthly basis and is calculated as a proportion of our total interest expense on the Credit Facility. On April 26, 2018, Archrock terminated its credit facility and repaid the $63.2 million in outstanding borrowings and accrued and unpaid interest and fees under the Archrock credit facility with a borrowing under the Revolving Loan Agreement. See Note 6 (“Long-Term Debt”) and Note 7 (“Partners’ Capital”) for further details of the Merger and our pay down of the Archrock credit facility. At September 30, 2018 , the balance of outstanding borrowings under the Revolving Loan Agreement was $53.5 million . During the three and nine months ended September 30, 2018 , we recorded $0.7 million and $1.3 million , respectively, of interest income earned on loans to Archrock under the Revolving Loan Agreement which was included in interest expense, net in our condensed consolidated statements of operations. Omnibus Agreement Our Omnibus Agreement with Archrock provides for, among other things: • Archrock’s obligation to provide all operational staff, corporate staff and support services reasonably necessary to operate our business and our obligation to reimburse Archrock for such services; • the terms under which we, Archrock and our respective affiliates may transfer, exchange or lease compression equipment among one another; • Archrock’s grant to us of a license to use certain intellectual property, including the “Archrock” logo; and • Archrock’s and our obligations to indemnify each other for certain liabilities. Common Control Transactions Transactions between us and Archrock and its affiliates are transactions between entities under common control. Under GAAP, transfers of assets and liabilities between entities under common control are to be initially recorded on the books of the receiving entity at the carrying value of the transferor. Any difference between consideration given and the carrying value of the assets or liabilities is treated as a capital distribution or contribution. Transfer, Exchange or Lease of Compression Equipment with Archrock If Archrock determines in good faith that we or Archrock’s contract operations services business need to transfer, exchange or lease compression equipment between Archrock and us, the Omnibus Agreement permits such equipment to be transferred, exchanged or leased if it will not cause us to breach any existing contracts, suffer a loss of revenue under an existing compression services contract or incur any unreimbursed costs. In consideration for such transfer, exchange or lease of compression equipment, the transferee will either (i) transfer to the transferor compression equipment equal in value to the appraised value of the compression equipment transferred to it, (ii) agree to lease such compression equipment from the transferor or (iii) pay the transferor an amount in cash equal to the appraised value of the compression equipment transferred to it. The TCJA made significant changes to the determination of partnership taxable income that included the cessation of like-kind exchange treatment for exchanges of tangible personal property. In accordance with this change, we no longer perform such exchanges as of January 1, 2018. Transfer and Exchange of Overhauls During the nine months ended September 30, 2018 and September 30, 2017 , Archrock contributed to us $1.7 million and $3.9 million , respectively, related to the completion of overhauls on compression equipment that was exchanged with us or contributed to us and where overhauls were in progress on the date of exchange or contribution. Other Exchanges The following table summarizes the like-kind exchange activity between Archrock and us for the nine months ended September 30, 2017 prior to the enactment of the TCJA (dollars in thousands): Nine Months Ended September 30, 2017 Transferred to Archrock Transferred from Archrock Compressor units 199 170 Horsepower 109,800 99,500 Net book value $ 47,824 $ 45,664 During the nine months ended September 30, 2017 , we recorded capital distributions of $2.1 million related to the differences in net book value on the exchanged compression equipment. No customer contracts were included in the exchanges. Leases The following table summarizes the aggregate cost and accumulated depreciation of equipment on lease to and from Archrock (in thousands): September 30, 2018 December 31, 2017 Equipment on lease to Archrock Aggregate cost $ 40,212 $ 3,560 Accumulated depreciation 5,783 272 Equipment on lease from Archrock Aggregate cost $ 67,048 $ 224 Accumulated depreciation 33,337 34 The following table summarizes the revenue from Archrock related to the lease of our compression equipment and the cost of sales related to the lease of Archrock compression equipment (in thousands): Nine Months Ended September 30, 2018 2017 Revenue $ 984 $ 356 Cost of sales 1,924 719 Reimbursement of Operating and SG&A Expense Archrock provides all operational staff, corporate staff and support services reasonably necessary to run our business. These services may include, without limitation, operations, marketing, maintenance and repair, periodic overhauls of compression equipment, inventory management, legal, accounting, treasury, insurance administration and claims processing, risk management, health, safety and environmental, information technology, human resources, credit, payroll, internal audit, taxes, facilities management, investor relations, enterprise resource planning system, training, executive, sales, business development and engineering. Archrock charges us for costs that are directly attributable to us. Costs that are indirectly attributable to us and Archrock’s other operations are allocated among Archrock’s other operations and us. The allocation methodologies vary based on the nature of the charge and have included, among other things, headcount and horsepower. We believe that the allocation methodologies used to allocate indirect costs to us are reasonable.

Contract Costs

Contract Costs	9 Months Ended
	Sep. 30, 2018
Other Income and Expenses [Abstract]
Contract Costs	3. Revenue from Contracts with Customers Revenue Recognition Revenue is recognized when control of the promised goods or services is transferred to our customers, in an amount that reflects the consideration we are entitled to receive in exchange for those goods or services. Sales and usage-based taxes that are collected from the customer are excluded from revenue. The following table presents our revenue from contracts with customers disaggregated by revenue source (in thousands): Three Months Ended September 30, 2018 Nine Months Ended September 30, 2018 0 - 1,000 horsepower per unit $ 55,215 $ 164,031 1,001 - 1,500 horsepower per unit 63,806 187,890 Over 1,500 horsepower per unit 34,156 98,056 Other (1) 856 1,924 Total revenue (2) $ 154,033 $ 451,901 —————— (1) Primarily relates to fees associated with Partnership-owned non-compressor equipment. (2) Includes $1.4 million and $3.9 million for three and nine months ended September 30, 2018 , respectively, related to billable maintenance on Partnership-owned units that was recognized at a point in time. All other revenue is recognized over time. Contract Operations We provide comprehensive contract operations services, including the personnel, equipment, tools, materials and supplies to meet our customers’ natural gas compression needs. Based on the operating specifications at the customer location and each customer's unique needs, these services include designing, sourcing, owning, installing, operating, servicing, repairing and maintaining equipment to provide natural gas compression services to our customers. Natural gas compression services are generally satisfied over time, as the customer simultaneously receives and consumes the benefits provided by these services. Our performance obligation is a series in which the unit of service is one month, as the customer receives substantially the same benefit each month from the services regardless of the type of service activity performed, which may vary. If the transaction price is based on a fixed fee, revenue is recognized monthly on a straight-line basis over the period that we are providing services to the customer. Amounts invoiced to customers for costs associated with moving our compressor assets to a customer site are also included in the transaction price and are amortized over the initial contract term. Variable consideration exists if customers are billed at a lesser standby rate when a unit is not running. We have elected to apply the invoicing practical expedient to recognize revenue for such variable consideration, as the invoice corresponds directly to the value transferred to the customer based on our performance completed to date. The rate for standby service is lower to reflect the decrease in costs and effort required to provide standby service when a unit is not running. We also perform billable maintenance service on our natural gas compression equipment at the customer’s request on an as-needed basis. The performance obligation is satisfied and revenue is recognized at the agreed-upon transaction price at the point in time when service is complete and the customer has accepted the work performed and can obtain the remaining benefits of the service that the unit will provide. As of September 30, 2018 , we had $249.7 million of remaining performance obligations related to our contract compression service. We have elected the practical expedient to not consider the effects of the time value of money, as the expected time between the transfer of services and payment for such services is less than one year. This amount will be recognized through 2022 as follows (in thousands): 2018 2019 2020 2021 2022 Total Remaining performance obligations $ 85,439 $ 110,145 $ 44,906 $ 8,132 $ 1,073 $ 249,695 Contract Balances Contract operations services are generally billed monthly at the beginning of the month in which service is being provided. We recognize a contract asset when we have the right to consideration in exchange for goods or services transferred to a customer when the right is conditioned on something other than the passage of time. We recognize a contract liability when we have an obligation to transfer goods or services to a customer for which we have already received consideration. Freight billings to transport compressor assets often result in a contract liability. As of September 30, and January 1, 2018 , our receivables from contracts with customers, net of allowance for doubtful accounts were $71.9 million and $66.2 million , respectively. As of September 30, and January 1, 2018 , our contract liabilities were $10.1 million and $5.4 million , respectively, which are included in deferred revenue and other long-term liabilities in our condensed consolidated balance sheets. The increase in the contract liability balance during the nine months ended September 30, 2018 was due to the deferral of $14.0 million partially offset by $9.3 million recognized as revenue during the period, each primarily related to freight billings. 5. Contract Costs We capitalize incremental costs to obtain a contract with a customer if we expect to recover those costs. Capitalized costs include commissions paid to our sales force to obtain contract operations contracts. As of September 30 , and January 1, 2018, we recorded contract costs of $3.3 million and $2.0 million , respectively, associated with sales commissions. We capitalize costs incurred to fulfill a contract if those costs relate directly to a contract, enhance resources that we will use in satisfying performance obligations and if we expect to recover those costs. Capitalized costs incurred to fulfill our customer contracts include freight charges to transport compressor assets before transferring services to the customer and mobilization activities associated with our contract operations services. As of September 30 , and January 1, 2018, we recorded contract costs of $26.2 million and $14.3 million , respectively, associated with freight and mobilization. Contract operations costs are amortized based on the transfer of service to which the assets relate, which is estimated to be 36 months based on average contract term, including anticipated renewals. We assess periodically whether the 36 -month estimate fairly represents the average contract term and adjust as appropriate. Contract costs associated with commissions are amortized to SG&A. Contract costs associated with freight and mobilization are amortized to cost of sales (excluding depreciation and amortization). During the three and nine months ended September 30, 2018 , we amortized $0.4 million and $0.9 million , respectively, related to commissions and $2.8 million and $7.1 million , respectively, related to freight and mobilization. During the three and nine months ended September 30, 2018 , there were no impairment losses recorded in relation to the costs capitalized.

Long-Term Debt

Long-Term Debt	9 Months Ended
	Sep. 30, 2018
Debt Disclosure [Abstract]
Long-Term Debt	6. Long-Term Debt Long-term debt consisted of the following (in thousands): September 30, 2018 December 31, 2017 Credit Facility $ 826,500 $ 674,306 6% senior notes due April 2021 350,000 350,000 Less: Debt discount, net of amortization (1,977 ) (2,523 ) Less: Deferred financing costs, net of amortization (2,568 ) (3,338 ) 345,455 344,139 6% senior notes due October 2022 350,000 350,000 Less: Debt discount, net of amortization (2,938 ) (3,441 ) Less: Deferred financing costs, net of amortization (3,338 ) (3,951 ) 343,724 342,608 Long-term debt $ 1,515,679 $ 1,361,053 Credit Facility The Credit Facility is a five -year, $1.25 billion asset-based revolving credit facility that will mature on March 30, 2022 except that if any portion of our 6% senior notes due April 2021 are outstanding as of December 2, 2020 , then maturity will instead be on December 2, 2020 . In March 2017, we incurred $14.9 million in transaction costs related to the formation of the Credit Facility. Concurrent with entering into the Credit Facility, we expensed $0.6 million of unamortized deferred financing costs and recorded a debt extinguishment loss of $0.3 million related to the termination of our Former Credit Facility. On February 23, 2018, we amended the Credit Facility to, among other things: • increase the maximum Total Debt to EBITDA ratios, as defined in the Credit Facility agreement (see below for the revised ratios), effective as of the execution of Amendment No. 1 on February 23, 2018; and • effective upon completion of the Merger on April 26, 2018: – increase the aggregate revolving commitment from $1.1 billion to $1.25 billion ; – increase the amount available for the issuance of letters of credit from $25.0 million to $50.0 million ; – increase the basket sizes under certain covenants including covenants limiting our ability to make investments, incur debt, make restricted payments, incur liens and make asset dispositions; – name Archrock Services, L.P., one of Archrock’s subsidiaries, as a borrower under the Credit Facility and certain of Archrock’s other subsidiaries as loan guarantors; and – amend the definition of “Borrowing Base” to include certain assets of Archrock’s subsidiaries. We incurred $3.3 million in transaction costs related to Amendment No. 1 which were included in other long-term assets in our condensed consolidated balance sheet and are being amortized over the term of the Credit Facility. On April 26, 2018, in connection with the Merger and Amendment No. 1, Archrock terminated its credit facility and we borrowed on our Credit Facility to repay the $63.2 million in borrowings and accrued and unpaid interest and fees outstanding under the Archrock credit facility, which we recorded as a loan receivable due from Archrock (see Note 4 (“Related Party Transactions”) for further details of the loan receivable). In addition, the $15.4 million of letters of credit outstanding under Archrock’s credit facility as of the Merger were converted to letters of credit under our Credit Facility. As of September 30, 2018 , we had $15.4 million outstanding letters of credit under the Credit Facility and the applicable margin on amounts outstanding under the Credit Facility was 3.2% . The weighted average annual interest rate on the outstanding balance under the Credit Facility, excluding the effect of interest rate swaps, was 5.5% and 4.8% at September 30, 2018 and December 31, 2017 , respectively. We incurred $0.6 million in commitment fees on the daily unused amount of the Credit Facility and Former Credit Facility during each of the three months ended September 30, 2018 and 2017 , and $1.7 million and $1.5 million during the nine months ended September 30, 2018 and 2017 , respectively. We must maintain the following consolidated financial ratios, as defined in the Credit Facility agreement: EBITDA to Interest Expense 2.5 to 1.0 Senior Secured Debt to EBITDA 3.5 to 1.0 Total Debt to EBITDA Through fiscal year 2018 5.95 to 1.0 Through fiscal year 2019 5.75 to 1.0 Through second quarter of 2020 5.50 to 1.0 Thereafter (1) 5.25 to 1.0 —————— (1) Subject to a temporary increase to 5.5 to 1.0 for any quarter during which an acquisition satisfying certain thresholds is completed and for the two quarters immediately following such quarter. As of September 30, 2018 , we had undrawn capacity of $408.1 million under the Credit Facility. As a result of the ratio requirements above, $324.0 million of the $408.1 million of undrawn capacity was available for additional borrowings as of September 30, 2018 . As of September 30, 2018 , we were in compliance with all covenants under the Credit Facility agreement. The Notes The Notes are guaranteed on a senior unsecured basis by all of our existing subsidiaries (other than Archrock Partners Finance Corp., which is a co-issuer of the Notes) and certain of our future subsidiaries. The Notes and the guarantees, respectively, are our and the guarantors’ general unsecured senior obligations, rank equally in right of payment with all of our and the guarantors’ other senior obligations, and are effectively subordinated to all of our and the guarantors’ existing and future secured debt to the extent of the value of the collateral securing such indebtedness. In addition, the Notes and guarantees are effectively subordinated to all existing and future indebtedness and other liabilities of any future non-guarantor subsidiaries. All of our subsidiaries are 100% owned, directly or indirectly, by us and guarantees by our subsidiaries are full and unconditional and constitute joint and several obligations. We have no assets or operations independent of our subsidiaries and there are no significant restrictions upon our subsidiaries’ ability to distribute funds to us. Archrock Partners Finance Corp. has no operations and does not have revenue other than as may be incidental as co-issuer of the Notes. Because we have no independent operations, the guarantees are full and unconditional (subject to customary release provisions) and constitute joint and several obligations of our subsidiaries other than Archrock Partners Finance Corp. and as a result, we have not included consolidated financial information of our subsidiaries.

Partners' Capital

Partners' Capital	9 Months Ended
	Sep. 30, 2018
Equity [Abstract]
Partners' Capital	7. Partners’ Capital Merger Transaction On April 26, 2018, Archrock completed the acquisition of all of our outstanding common units and we became a wholly-owned subsidiary of Archrock. With the closing of the Merger, Archrock issued 57.6 million shares of its common stock at a fixed exchange ratio of 1.40 shares for each of the 41.2 million common units not owned by Archrock prior to the Merger. Additionally, all outstanding treasury units were retired and our incentive distribution rights, all of which were previously owned indirectly by Archrock prior to the Merger, were canceled and ceased to exist. As a result of the Merger, our common units are no longer publicly traded. Our Notes were not impacted by the Merger and remain outstanding. Prior to the Merger, public unitholders held a 57% ownership interest in us and Archrock owned our remaining equity interests, including 29,064,637 common units and 1,422,458 general partner units, collectively representing a 43% interest in us. Capital Offering In August 2017, we sold, pursuant to a public underwritten offering, 4,600,000 common units, including 600,000 common units pursuant to an over-allotment option. We received net proceeds of $60.3 million after deducting underwriting discounts, commissions and offering expenses, which we used to repay borrowings outstanding under the Credit Facility. In connection with this sale and as permitted under our partnership agreement, we sold 93,163 general partner units to our general partner so it could maintain its approximate 2% general partner interest in us. We received net proceeds of $1.3 million from the general partner contribution. Cash Distributions As of the closing of the Merger, any distributions are paid to Archrock as the owner of all outstanding common and general partner units. In the nine months ended September 30, 2018 we paid cash distributions of $0.7492 per common unit, or $53.7 million , which covered the period from October 1, 2017 through June 30, 2018. On October 29, 2018 , our board of directors approved a cash distribution of $0.2432 per common unit, or approximately $17.4 million , which covers the period from July 1, 2018 through September 30, 2018.

Unit-Based Compensation

Unit-Based Compensation	9 Months Ended
	Sep. 30, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Unit-Based Compensation	8. Unit-Based Compensation Long-Term Incentive Plan In April 2017, we adopted the 2017 LTIP to provide for the benefit of the employees, directors and consultants of us, Archrock and our respective affiliates. The 2006 LTIP expired in 2016 and, as such, no further grants have been or can be made under that plan following expiration. Previous grants made under the 2006 LTIP continue to be governed by the 2006 LTIP and the applicable award agreements. Because we grant phantom units to non-employees, we are required to remeasure the fair value of these phantom units, which is based on the fair value of our common units, each period and record a cumulative adjustment of the expense previously recognized. Phantom units granted under the 2017 and 2006 LTIP may include nonforfeitable tandem distribution equivalent rights to receive cash distributions on unvested phantom units in the quarter in which distributions are paid on common units. Phantom units granted generally vest one-third per year on dates as specified in the applicable award agreements subject to continued service through the applicable vesting date. During the nine months ended September 30, 2018, 53,091 phantom units vested with a weighted average grant date fair value per unit of $11.24 . Pursuant to the Merger, all outstanding phantom units previously granted under the 2017 and 2006 Partnership LTIP were converted into comparable awards based on Archrock’s common shares. As such, all outstanding phantom units were converted, effective as of the closing of the Merger, into Archrock restricted stock units. See Note 7 (“Partners’ Capital”) for further details of the Merger. Each Archrock restricted stock unit will be subject to the same vesting, forfeiture and other terms and conditions applicable to the converted Partnership phantom units.

Derivatives

Derivatives	9 Months Ended
	Sep. 30, 2018
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivatives	9. Derivatives We are exposed to market risks associated with changes in the variable interest rate of the Partnership Credit Facility. We use derivative instruments to manage our exposure to fluctuations in this variable interest rate and thereby minimize the risks and costs associated with financial activities. We do not use derivative instruments for trading or other speculative purposes. At September 30, 2018 , we were a party to the following interest rate swaps, which were entered into to offset changes in expected cash flows due to fluctuations in the associated variable interest rates (in millions): Expiration Date Notional Value May 2019 $ 100.0 May 2020 100.0 March 2022 300.0 $ 500.0 The counterparties to our derivative agreements are major financial institutions. We monitor the credit quality of these financial institutions and do not expect non-performance by any counterparty, although such non-performance could have a material adverse effect on us. We have no specific collateral posted for our derivative instruments. We have designated these interest rate swaps as cash flow hedging instruments and so any change in their fair value is recognized as a component of other comprehensive income (loss) until the hedged transaction affects earnings. At that time, amounts are reclassified into earnings to interest expense, net, the same statement of operations line item to which the earnings effect of the hedged item is recorded. Cash flows from derivatives designated as hedges are classified in our condensed consolidated statements of cash flows under the same category as the cash flows from the underlying assets, liabilities or anticipated transactions, unless the derivative contract contains a significant financing element; in this case, the cash settlements for these derivatives are classified as cash flows from financing activities. We expect the hedging relationship to be highly effective as the swap terms substantially coincide with the hedged item and are expected to offset changes in expected cash flows due to fluctuations in the variable rate. Prior to adoption of ASU 2017-12, we performed quarterly calculations to determine whether the swap agreements continued to be highly effective at achieving offsetting changes in cash flows attributable to the hedged risk. Upon adoption of ASU 2017-12, we perform quarterly qualitative prospective and retrospective hedge effectiveness assessments unless facts and circumstances related to the hedging relationships change such that we can no longer assert qualitatively that the cash flow hedge relationships were and continue to be highly effective. We estimate that $3.6 million of the deferred gain attributable to interest rate swaps included in accumulated other comprehensive income (loss) at September 30, 2018 will be reclassified into earnings as interest income at then-current values during the next twelve months as the underlying hedged transactions occur. In August 2017, we amended the terms of $300.0 million of our interest rate swap agreements to adjust the fixed interest rate and extend the maturity dates to March 2022. These amendments effectively created new derivative contracts and terminated the old derivative contracts. As a result, as of the amendment date, we discontinued the original cash flow hedge relationships on a prospective basis and designated the amended interest rate swaps under new cash flow hedge relationships based on the amended terms. The fair value of the interest rate swaps immediately prior to the execution of the amendments was a liability of $0.7 million . The associated amount in accumulated other comprehensive income (loss) was amortized into interest expense over the original terms of the interest rate swaps through May 2018. As of September 30, 2018 , the weighted average effective fixed interest rate on our interest rate swaps was 1.8% . The following table presents the effect of our derivative instruments designated as cash flow hedging instruments on our condensed consolidated balance sheets (in thousands): Fair Value Asset (Liability) September 30, 2018 December 31, 2017 Current portion of interest rate swaps $ 3,592 $ 186 Other long-term assets 9,487 4,490 Current portion of interest rate swaps — (134 ) $ 13,079 $ 4,542 The following tables present the effect of our derivative instruments designated as cash flow hedging instruments on our consolidated statements of operations (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2018 2017 2018 2017 Pre-tax gain recognized in other comprehensive income (loss) $ 1,642 $ 1,919 $ 8,583 $ 2,282 Pre-tax gain (loss) reclassified from accumulated other comprehensive income (loss) into interest expense, net 429 (652 ) (20 ) (2,427 ) Three Months Ended September 30, 2018 Nine Months Ended September 30, 2018 Total amount of interest expense, net in which the effects of cash flow hedges are recorded $ 22,767 $ 66,918 Amount of gain reclassified from accumulated other comprehensive income (loss) into interest expense, net 429 582

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2018
Fair Value Disclosures [Abstract]
Fair Value Measurements	10. Fair Value Measurements The accounting standard for fair value measurements and disclosures establishes a fair value hierarchy that prioritizes the inputs of valuation techniques used to measure fair value into the following three categories: • Level 1 — Quoted unadjusted prices for identical instruments in active markets to which we have access at the date of measurement. • Level 2 — Quoted prices for similar instruments in active markets, quoted prices for identical or similar instruments in markets that are not active and model-derived valuations in which all significant inputs and significant value drivers are observable in active markets. Level 2 inputs are those in markets for which there are few transactions, the prices are not current, little public information exists or prices vary substantially over time or among brokered market makers. • Level 3 — Model-derived valuations in which one or more significant inputs or significant value drivers are unobservable. Unobservable inputs are those inputs that reflect our own assumptions regarding how market participants would price the asset or liability based on the best available information. Assets and Liabilities Measured at Fair Value on a Recurring Basis On a quarterly basis, our interest rate swaps are valued based on the income approach (discounted cash flow) using market observable inputs, including London Interbank Offered Rate forward curves. These fair value measurements are classified as Level 2. The following table presents our interest rate swaps asset and liability measured at fair value on a recurring basis with pricing levels as of the date of valuation (in thousands): September 30, 2018 December 31, 2017 Interest rate swaps asset $ 13,079 $ 4,676 Interest rate swaps liability — (134 ) Assets and Liabilities Measured at Fair Value on a Nonrecurring Basis During the nine months ended September 30, 2018 , we recorded non-recurring fair value measurements related to our idle and previously-culled compressor units. Our estimate of the compressor units’ fair value was primarily based on the expected net sale proceeds compared to other fleet units we recently sold and/or a review of other units recently offered for sale by third parties, or the estimated component value of the equipment we plan to use. We discounted the expected proceeds, net of selling and other carrying costs, using a weighted average disposal period of four years . These fair value measurements are classified as Level 3. The fair value of our impaired compressor units was $0.8 million and $1.8 million at September 30, 2018 and December 31, 2017 , respectively. See Note 11 (“Long-Lived Asset Impairment”) for further details. Other Financial Instruments The carrying amounts of our cash, receivables and payables approximate fair value due to the short-term nature of those instruments. The carrying amount of borrowings outstanding under our Credit Facility approximates fair value due to its variable interest rate. The fair value of these outstanding borrowings was estimated using a discounted cash flow analysis based on interest rates offered on loans with similar terms to borrowers of similar credit quality, which are Level 3 inputs. The fair value of our fixed rate debt was estimated based on quoted prices in inactive markets and is considered a Level 2 measurement. The following table summarizes the carrying amount and fair value of our fixed rate debt (in thousands): September 30, 2018 December 31, 2017 Carrying amount of fixed rate debt (1) $ 689,179 $ 686,747 Fair value of fixed rate debt 706,000 702,000 —————— (1) Carrying amounts are shown net of unamortized debt discounts and unamortized deferred financing costs. See Note 6 (“Long-Term Debt”) for further details.

Long-Lived Asset Impairment

Long-Lived Asset Impairment	9 Months Ended
	Sep. 30, 2018
Asset Impairment Charges [Abstract]
Long-Lived Asset Impairment	11. Long-Lived Asset Impairment We review long-lived assets, including property, plant and equipment and identifiable intangibles that are being amortized, for impairment whenever events or changes in circumstances, including the removal of compressor units from our active fleet, indicate that the carrying amount of an asset may not be recoverable. We periodically review the future deployment of our idle compression assets for units that are not of the type, configuration, condition, make or model that are cost efficient to maintain and operate. Based on these reviews, we determine that certain idle compressor units should be retired from the active fleet. The retirement of these units from the active fleet triggers a review of these assets for impairment and as a result of our review, we may record an asset impairment to reduce the book value of each unit to its estimated fair value. The fair value of each unit is estimated based on the expected net sale proceeds compared to other fleet units we recently sold, a review of other units recently offered for sale by third parties or the estimated component value of the equipment we plan to use. In connection with our review of our idle compression assets, we evaluate for impairment idle units that were culled from our fleet in prior years and are available for sale. Based on that review, we may reduce the expected proceeds from disposition and record additional impairment to reduce the book value of each unit to its estimated fair value. The following table presents the results of our impairment review (dollars in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2018 2017 2018 2017 Idle compressor units retired from the active fleet 35 45 140 150 Horsepower of idle compressor units retired from the active fleet 14,000 18,000 44,000 53,000 Impairment recorded on idle compressor units retired from the active fleet $ 3,673 $ 5,368 $ 10,585 $ 14,659

Income Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2018
Income Tax Disclosure [Abstract]
Income Taxes	12. Income Taxes Unrecognized Tax Benefits As of September 30, 2018 , we believe $0.9 million of our unrecognized tax benefits will be reduced prior to September 30, 2019 due to the settlement of audits or the expiration of statutes of limitations or both. However, due to the uncertain and complex application of the tax regulations, it is possible that the ultimate resolution of these matters may result in liabilities which could materially differ from this estimate.

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2018
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	13. Commitments and Contingencies Insurance Matters Our business can be hazardous, involving unforeseen circumstances such as uncontrollable flows of natural gas or well fluids and fires or explosions. Archrock insures our property and operations against many, but not all, of these risks. We believe that our insurance coverage is customary for the industry and adequate for our business; however, losses and liabilities not covered by insurance would increase our costs. In addition, Archrock is substantially self-insured for worker’s compensation, employer’s liability, property, auto liability, general liability and employee group health claims in view of the relatively high per-incident deductibles it absorbs under its insurance arrangements for these risks. Losses up to the deductible amounts are estimated and accrued based upon known facts, historical trends and industry averages. Tax Matters We are subject to a number of state and local taxes that are not income-based. As many of these taxes are subject to audit by the taxing authorities, it is possible that an audit could result in additional taxes due. We accrue for such additional taxes when we determine that it is probable that we have incurred a liability and we can reasonably estimate the amount of the liability. As of September 30, 2018 and December 31, 2017 , we accrued $2.7 million and $1.6 million , respectively, for the outcomes of non-income based tax audits. We do not expect that the ultimate resolutions of these audits will result in a material variance from the amounts accrued. We do not accrue for unasserted claims for tax audits unless we believe the assertion of a claim is probable, it is probable that it will be determined that the claim is owed and we can reasonably estimate the claim or range of the claim. We believe the likelihood is remote that the impact of potential unasserted claims from non-income based tax audits could be material to our consolidated financial position, but it is possible that the resolution of future audits could be material to our consolidated results of operations or cash flows. Litigation and Claims In the ordinary course of business, we are involved in various pending or threatened legal actions. While management is unable to predict the ultimate outcome of these actions, it believes that any ultimate liability arising from any of these actions will not have a material adverse effect on our consolidated financial position, results of operations or cash flows, including our ability to make cash distributions to Archrock. However, because of the inherent uncertainty of litigation and arbitration proceedings, we cannot provide assurance that the resolution of any particular claim or proceeding to which we are a party will not have a material adverse effect on our consolidated financial position, results of operations or cash flows, including our ability to make cash distributions to Archrock. Heavy Equipment In 2011, the Texas Legislature enacted changes that affected the appraisal of natural gas compressors for ad valorem tax purposes by expanding the special valuation methodology for “Heavy Equipment Inventory” to include inventory held for lease effective from the beginning of 2012. Under the Heavy Equipment Statutes, we are a “Heavy Equipment Dealer” and our natural gas compressors are Heavy Equipment Inventory. As such, we began filing our ad valorem taxes under this methodology starting in the 2012 tax year. Our natural gas compressors are taxable under the Heavy Equipment Statutes in the counties where we maintain a business location and store our inventory of natural gas compressors as opposed to where the compressors may be located on January 1 of a tax year. Although a few appraisal review boards accepted our position, many denied it. As a result, our wholly-owned subsidiary, Archrock Partners Leasing LLC, formerly known as EXLP Leasing, and Archrock’s wholly-owned subsidiary, Archrock Services Leasing LLC, formerly known as EES Leasing, filed numerous petitions for review in the appropriate district courts with respect to the 2012-2017 tax years. To date, three cases have been decided by trial courts, with two of the decisions having been rendered by the same presiding judge. All three of those decisions were appealed, and all three of the appeals have been decided on by intermediate appellate courts. On March 2, 2018, the Texas Supreme Court ruled in one of the cases, EXLP Leasing LLC & EES Leasing LLC v. Galveston Central Appraisal District , on two of the three issues related to the Heavy Equipment Statutes: constitutionality and situs. The third issue — the district court’s ruling that the Heavy Equipment Statutes apply to the compressors — was not appealed in this case. The Texas Supreme Court ruled in our favor on all accounts, holding that the Heavy Equipment Statutes are constitutional and that our natural gas compressors are taxable only in the counties where we maintain a business location that manages our inventory of natural gas compressors. On September 28, 2018, the Texas Supreme Court denied Galveston Central Appraisal District’s motion for rehearing, thus concluding the litigation in this case. Two cases, EXLP Leasing LLC & EES Leasing LLC v. Loving County Appraisal District and EES Leasing LLC & EXLP Leasing LLC v. Ward County Appraisal District , remain pending for review by the Texas Supreme Court. We expect the pending cases to be disposed of in a manner consistent with the Galveston case. As a result of the rulings on the Heavy Equipment litigation thus far, all counties in which we filed petitions for review have removed our compressors from their 2018 property rolls except for Galveston County, which has agreed to do so promptly. As of September 30, 2018, many of the petitions that we filed for tax years 2012-2017 have been closed and the remaining pending petitions are in the process of being closed. We believe that the likelihood of an unfavorable outcome or further litigation on this issue is remote.

Recent Accounting Developments

Recent Accounting Developments Recent Accounting Developments (Policies)	9 Months Ended
	Sep. 30, 2018
New Accounting Pronouncements and Changes in Accounting Principles [Abstract]
Revenue Recognition Update	Revenue Recognition Update On January 1, 2018, we adopted the Revenue Recognition Update using the modified retrospective method applied to those contracts which were not completed as of January 1, 2018. We recognized the cumulative effect of initially applying the Revenue Recognition Update as an adjustment to the opening balance of retained earnings. For contracts that were modified before the effective date, we identified performance obligations on the basis of the current version of the contract, which included any contract modifications since inception. The application of the practical expedient for contract modifications did not have a material effect on the adjustment to retained earnings. The comparative information has not been restated and continues to be reported under the accounting standards in effect for those periods. Under previous guidance, contract operations revenue was recognized when earned, which generally occurs monthly when the service is provided under our customer contracts. Under the Revenue Recognition Update the timing of revenue recognition is impacted by contractual provisions for service availability guarantees of our compressor assets and re-billable costs associated with moving our compressor assets to a customer site. These changes are further discussed below and did not result in a material difference from previous practice for contract operations. The Revenue Recognition Update provides guidance on contract costs that should be recognized as assets and amortized over the period that the related goods or services transfer to the customer. Certain costs that were previously expensed as incurred, such as sales commissions and freight charges to transport compressor assets, are deferred and amortized. The following table summarizes the cumulative impact of the adoption of the Revenue Recognition Update on the opening balance sheet (in thousands): December 31, 2017 Adjustments Due to the Revenue Recognition Update January 1, 2018 Assets Contract costs $ — $ 16,316 $ 16,316 Liabilities Accrued liabilities $ 7,597 $ 186 $ 7,783 Deferred revenue 1,299 3,416 4,715 Partners ’ capital Common units $ 501,023 $ 12,462 $ 513,485 General partner units 11,582 252 11,834 The following tables summarize the impact of the application of the Revenue Recognition Update on our condensed consolidated balance sheet and condensed consolidated statement of operations (in thousands): September 30, 2018 Balance Sheet As Reported Balance Excluding the Impact of the Revenue Recognition Update Effect of Change Assets Accounts receivable, trade $ 73,258 $ 72,902 $ 356 Contract costs 29,531 — 29,531 Liabilities Accrued liabilities $ 10,489 $ 10,256 $ 233 Deferred revenue 9,881 2,137 7,744 Other long-term liabilities 9,529 9,534 (5 ) Equity Common units $ 493,197 $ 471,779 $ 21,418 General partner units 11,448 10,951 497 Three Months Ended September 30, 2018 Statement of Operations As Reported Balance Excluding the Impact of the Revenue Recognition Update Effect of Change Revenue $ 154,033 $ 155,377 $ (1,344 ) Cost of sales (excluding depreciation and amortization) 62,068 66,388 (4,320 ) Selling, general and administrative 18,143 18,693 (550 ) Provision for income taxes 546 539 7 Net income 12,613 9,094 3,519 Nine Months Ended September 30, 2018 Statement of Operations As Reported Balance Excluding the Impact of the Revenue Recognition Update Effect of Change Revenue $ 451,901 $ 455,920 $ (4,019 ) Cost of sales (excluding depreciation and amortization) 178,596 190,425 (11,829 ) Selling, general and administrative 57,288 58,674 (1,386 ) Provision for income taxes 648 653 (5 ) Net income 33,384 24,183 9,201
New Accounting Pronouncements	Accounting Standards Updates Implemented On January 1, 2018, we adopted ASU 2017-12 using the modified retrospective approach to existing cash flow hedge relationships as of January 1, 2018. ASU 2017-12 expands and refines hedge accounting for both financial and nonfinancial risk components, aligns the recognition and presentation of the effects of the hedging instrument and hedged item in the financial statements and eliminates the requirement to separately measure and report hedge ineffectiveness. As a result of the adoption of ASU 2017-12, we recognized a net gain of $0.4 million as a cumulative-effect adjustment to opening partners’ capital and a corresponding adjustment to other comprehensive income (loss) to reverse the cumulative ineffectiveness previously recognized in interest expense. On January 1, 2018, we adopted ASU 2016-15 on a retrospective basis. ASU 2016-15 addresses diversity in practice and simplifies several elements of cash flow classification including how certain cash receipts and cash payments are classified in the statement of cash flows. ASU 2016-15 did not have an impact on our condensed consolidated statement of cash flow for the nine months ended September 30, 2017 . Accounting Standards Updates Not Yet Implemented In August 2018, the FASB issued ASU 2018-13 which amends the required fair value measurements disclosures related to valuation techniques and inputs used, uncertainty in measurement, and changes in measurements applied. These amendments are effective for all entities for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2019. Early adoption is permitted. We are currently evaluating the impact of ASU 2018-13 on our consolidated financial statements and footnote disclosures. In June 2016, the FASB issued ASU 2016-13 that changes the impairment model for most financial assets and certain other instruments, including trade and other receivables, held-to-maturity debt securities and loans, and requires entities to use a new forward-looking expected loss model that will result in the earlier recognition of allowance for losses. For public entities that meet the definition of an SEC filer, ASU 2016-13 is effective for fiscal years beginning after December 15, 2019 and early adoption is permitted. Entities will apply ASU 2016-13 provisions as a cumulative-effect adjustment to retained earnings as of the beginning of the first reporting period in which the guidance is adopted. We are currently evaluating the impact of ASU 2016-13 on our consolidated financial statements and footnote disclosures.
Leases	Leases ASC Topic 842 Leases establishes a ROU model that requires a lessee to record a ROU asset and a lease liability on the balance sheet for all leases with terms longer than 12 months. Leases will be classified as either finance or operating, with classification affecting the pattern of expense recognition in the income statement. Under the new guidance, lessor accounting is largely unchanged. ASC Topic 842 Leases is effective for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. A modified retrospective transition approach that involves recasting the comparative periods in the year of initial application is required for leases existing at, or entered into after, the beginning of the earliest comparative period presented in the financial statements, with certain transition practical expedients available. In July 2018 the FASB provided an optional transition method that would allow adoption of the standard as of the effective date without restating prior periods. We intend to adopt ASC Topic 842 Leases on January 1, 2019 using the optional transition method and are currently assessing the transition practical expedients. Upon adoption, we will recognize the cumulative effect of adoption as an adjustment to the opening balance of our retained earnings. Comparative information will continue to be reported under the accounting standards in effect for those periods.

Recent Accounting Development_2

Recent Accounting Developments (Tables)	9 Months Ended
	Sep. 30, 2018
New Accounting Pronouncements and Changes in Accounting Principles [Abstract]
Schedule of New Accounting Pronouncements and Changes in Accounting Principles	The following table summarizes the cumulative impact of the adoption of the Revenue Recognition Update on the opening balance sheet (in thousands): December 31, 2017 Adjustments Due to the Revenue Recognition Update January 1, 2018 Assets Contract costs $ — $ 16,316 $ 16,316 Liabilities Accrued liabilities $ 7,597 $ 186 $ 7,783 Deferred revenue 1,299 3,416 4,715 Partners ’ capital Common units $ 501,023 $ 12,462 $ 513,485 General partner units 11,582 252 11,834 The following tables summarize the impact of the application of the Revenue Recognition Update on our condensed consolidated balance sheet and condensed consolidated statement of operations (in thousands): September 30, 2018 Balance Sheet As Reported Balance Excluding the Impact of the Revenue Recognition Update Effect of Change Assets Accounts receivable, trade $ 73,258 $ 72,902 $ 356 Contract costs 29,531 — 29,531 Liabilities Accrued liabilities $ 10,489 $ 10,256 $ 233 Deferred revenue 9,881 2,137 7,744 Other long-term liabilities 9,529 9,534 (5 ) Equity Common units $ 493,197 $ 471,779 $ 21,418 General partner units 11,448 10,951 497 Three Months Ended September 30, 2018 Statement of Operations As Reported Balance Excluding the Impact of the Revenue Recognition Update Effect of Change Revenue $ 154,033 $ 155,377 $ (1,344 ) Cost of sales (excluding depreciation and amortization) 62,068 66,388 (4,320 ) Selling, general and administrative 18,143 18,693 (550 ) Provision for income taxes 546 539 7 Net income 12,613 9,094 3,519 Nine Months Ended September 30, 2018 Statement of Operations As Reported Balance Excluding the Impact of the Revenue Recognition Update Effect of Change Revenue $ 451,901 $ 455,920 $ (4,019 ) Cost of sales (excluding depreciation and amortization) 178,596 190,425 (11,829 ) Selling, general and administrative 57,288 58,674 (1,386 ) Provision for income taxes 648 653 (5 ) Net income 33,384 24,183 9,201

Revenue from Contracts with C_2

Revenue from Contracts with Customers (Tables)	9 Months Ended
	Sep. 30, 2018
Revenue from Contract with Customer [Abstract]
Disaggregation of Revenue	The following table presents our revenue from contracts with customers disaggregated by revenue source (in thousands): Three Months Ended September 30, 2018 Nine Months Ended September 30, 2018 0 - 1,000 horsepower per unit $ 55,215 $ 164,031 1,001 - 1,500 horsepower per unit 63,806 187,890 Over 1,500 horsepower per unit 34,156 98,056 Other (1) 856 1,924 Total revenue (2) $ 154,033 $ 451,901 —————— (1) Primarily relates to fees associated with Partnership-owned non-compressor equipment. (2) Includes $1.4 million and $3.9 million for three and nine months ended September 30, 2018 , respectively, related to billable maintenance on Partnership-owned units that was recognized at a point in time. All other revenue is recognized over time.
Remaining Performance Obligation Satisfaction	As of September 30, 2018 , we had $249.7 million of remaining performance obligations related to our contract compression service. We have elected the practical expedient to not consider the effects of the time value of money, as the expected time between the transfer of services and payment for such services is less than one year. This amount will be recognized through 2022 as follows (in thousands): 2018 2019 2020 2021 2022 Total Remaining performance obligations $ 85,439 $ 110,145 $ 44,906 $ 8,132 $ 1,073 $ 249,695

Related Party Transactions (Tab

Related Party Transactions (Tables)	9 Months Ended
	Sep. 30, 2018
Related Party Transactions [Abstract]
Schedule of Related Party Transactions	The following table summarizes the aggregate cost and accumulated depreciation of equipment on lease to and from Archrock (in thousands): September 30, 2018 December 31, 2017 Equipment on lease to Archrock Aggregate cost $ 40,212 $ 3,560 Accumulated depreciation 5,783 272 Equipment on lease from Archrock Aggregate cost $ 67,048 $ 224 Accumulated depreciation 33,337 34 The following table summarizes the revenue from Archrock related to the lease of our compression equipment and the cost of sales related to the lease of Archrock compression equipment (in thousands): Nine Months Ended September 30, 2018 2017 Revenue $ 984 $ 356 Cost of sales 1,924 719 The following table summarizes the like-kind exchange activity between Archrock and us for the nine months ended September 30, 2017 prior to the enactment of the TCJA (dollars in thousands): Nine Months Ended September 30, 2017 Transferred to Archrock Transferred from Archrock Compressor units 199 170 Horsepower 109,800 99,500 Net book value $ 47,824 $ 45,664

Long-Term Debt (Tables)

Long-Term Debt (Tables)	9 Months Ended
	Sep. 30, 2018
Debt Disclosure [Abstract]
Schedule of Long-term Debt	Long-term debt consisted of the following (in thousands): September 30, 2018 December 31, 2017 Credit Facility $ 826,500 $ 674,306 6% senior notes due April 2021 350,000 350,000 Less: Debt discount, net of amortization (1,977 ) (2,523 ) Less: Deferred financing costs, net of amortization (2,568 ) (3,338 ) 345,455 344,139 6% senior notes due October 2022 350,000 350,000 Less: Debt discount, net of amortization (2,938 ) (3,441 ) Less: Deferred financing costs, net of amortization (3,338 ) (3,951 ) 343,724 342,608 Long-term debt $ 1,515,679 $ 1,361,053 We must maintain the following consolidated financial ratios, as defined in the Credit Facility agreement: EBITDA to Interest Expense 2.5 to 1.0 Senior Secured Debt to EBITDA 3.5 to 1.0 Total Debt to EBITDA Through fiscal year 2018 5.95 to 1.0 Through fiscal year 2019 5.75 to 1.0 Through second quarter of 2020 5.50 to 1.0 Thereafter (1) 5.25 to 1.0 —————— (1) Subject to a temporary increase to 5.5 to 1.0 for any quarter during which an acquisition satisfying certain thresholds is completed and for the two quarters immediately following such quarter.

Derivatives (Tables)

Derivatives (Tables)	9 Months Ended
	Sep. 30, 2018
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule of Derivative Instruments	At September 30, 2018 , we were a party to the following interest rate swaps, which were entered into to offset changes in expected cash flows due to fluctuations in the associated variable interest rates (in millions): Expiration Date Notional Value May 2019 $ 100.0 May 2020 100.0 March 2022 300.0 $ 500.0
Effect of Derivative Instruments on Consolidated Financial Position	The following table presents the effect of our derivative instruments designated as cash flow hedging instruments on our condensed consolidated balance sheets (in thousands): Fair Value Asset (Liability) September 30, 2018 December 31, 2017 Current portion of interest rate swaps $ 3,592 $ 186 Other long-term assets 9,487 4,490 Current portion of interest rate swaps — (134 ) $ 13,079 $ 4,542
Effect of Derivative Instruments on Results of Operations	The following tables present the effect of our derivative instruments designated as cash flow hedging instruments on our consolidated statements of operations (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2018 2017 2018 2017 Pre-tax gain recognized in other comprehensive income (loss) $ 1,642 $ 1,919 $ 8,583 $ 2,282 Pre-tax gain (loss) reclassified from accumulated other comprehensive income (loss) into interest expense, net 429 (652 ) (20 ) (2,427 ) Three Months Ended September 30, 2018 Nine Months Ended September 30, 2018 Total amount of interest expense, net in which the effects of cash flow hedges are recorded $ 22,767 $ 66,918 Amount of gain reclassified from accumulated other comprehensive income (loss) into interest expense, net 429 582

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2018
Fair Value Disclosures [Abstract]
Schedule of Assets and Liabilities Measured at Fair Value on a Recurring Basis with Pricing Levels as of The Date of Valuation	The following table presents our interest rate swaps asset and liability measured at fair value on a recurring basis with pricing levels as of the date of valuation (in thousands): September 30, 2018 December 31, 2017 Interest rate swaps asset $ 13,079 $ 4,676 Interest rate swaps liability — (134 )
Schedule of Carrying Value and Estimated Fair Value of Debt Instruments	The following table summarizes the carrying amount and fair value of our fixed rate debt (in thousands): September 30, 2018 December 31, 2017 Carrying amount of fixed rate debt (1) $ 689,179 $ 686,747 Fair value of fixed rate debt 706,000 702,000 —————— (1) Carrying amounts are shown net of unamortized debt discounts and unamortized deferred financing costs. See Note 6 (“Long-Term Debt”) for further details.

Long-Lived Asset Impairment (Ta

Long-Lived Asset Impairment (Tables)	9 Months Ended
	Sep. 30, 2018
Asset Impairment Charges [Abstract]
Details of Impairment of Long-Lived Assets Held and Used by Asset	The following table presents the results of our impairment review (dollars in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2018 2017 2018 2017 Idle compressor units retired from the active fleet 35 45 140 150 Horsepower of idle compressor units retired from the active fleet 14,000 18,000 44,000 53,000 Impairment recorded on idle compressor units retired from the active fleet $ 3,673 $ 5,368 $ 10,585 $ 14,659

Recent Accounting Development_3

Recent Accounting Developments (Narratives) (Details) - ASU 2017-12 - USD ($) $ in Thousands	Jan. 01, 2018	Dec. 31, 2017
New Accounting Pronouncements or Change in Accounting Principle
Impact of adoption of new accounting principle		$ 383
Retained earnings
New Accounting Pronouncements or Change in Accounting Principle
Impact of adoption of new accounting principle	$ 400
Accumulated Other Comprehensive Income (Loss)
New Accounting Pronouncements or Change in Accounting Principle
Impact of adoption of new accounting principle	$ (400)

Recent Accounting Development_4

Recent Accounting Developments - Balance Sheet Impact (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Jan. 01, 2018	Dec. 31, 2017
Assets
Contract costs	$ 29,531	$ 16,316	$ 0
Liabilities
Accrued liabilities	10,489	7,783	7,597
Deferred revenue	9,881	4,715	1,299
Other long-term liabilities	9,529		9,356
Partners’ capital
Common units	493,197	513,485	501,023
General partner units	11,448	11,834	11,582
Balance Excluding the Impact of the Revenue Recognition Update
Assets
Contract costs	0		0
Accounts receivable, trade	72,902
Liabilities
Accrued liabilities	10,256		7,597
Deferred revenue	2,137		1,299
Other long-term liabilities	9,534
Partners’ capital
Common units	471,779		501,023
General partner units	10,951		$ 11,582
Adjustments Due to the Revenue Recognition Update | ASU 2014-09
Assets
Contract costs	29,531	16,316
Accounts receivable, trade	356
Liabilities
Accrued liabilities	233	186
Deferred revenue	7,744	3,416
Other long-term liabilities	(5)
Partners’ capital
Common units	21,418	12,462
General partner units	$ 497	$ 252

Recent Accounting Development_5

Recent Accounting Developments - Income Statement Impact (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Revenue, Initial Application Period Cumulative Effect Transition
Revenue	$ 154,033	$ 140,191	$ 451,901	$ 415,741
Cost of sales (excluding depreciation and amortization)	62,068	62,584	178,596	172,856
Selling, general and administrative	18,143	20,711	57,288	59,325
Provision for income taxes	546	708	648	2,970
Net income	12,613	$ (4,013)	33,384	$ (3,054)
Balance Excluding the Impact of the Revenue Recognition Update
Revenue, Initial Application Period Cumulative Effect Transition
Revenue	155,377		455,920
Cost of sales (excluding depreciation and amortization)	66,388		190,425
Selling, general and administrative	18,693		58,674
Provision for income taxes	539		653
Net income	9,094		24,183
Adjustments Due to the Revenue Recognition Update | ASU 2014-09
Revenue, Initial Application Period Cumulative Effect Transition
Revenue	(1,344)		(4,019)
Cost of sales (excluding depreciation and amortization)	(4,320)		(11,829)
Selling, general and administrative	(550)		(1,386)
Provision for income taxes	7		(5)
Net income	$ 3,519		$ 9,201

Revenue from Contracts with C_3

Revenue from Contracts with Customers - Disaggregate Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Disaggregation of Revenue
Contract revenue	$ 154,033	$ 140,191	$ 451,901	$ 415,741
0 - 1,000 horsepower per unit
Disaggregation of Revenue
Contract revenue	55,215		164,031
1,001 - 1,500 horsepower per unit
Disaggregation of Revenue
Contract revenue	63,806		187,890
Over 1,500 horsepower per unit
Disaggregation of Revenue
Contract revenue	34,156		98,056
Other
Disaggregation of Revenue
Contract revenue	856		1,924
Other | Transferred at point in time
Disaggregation of Revenue
Contract revenue	$ 1,400		$ 3,900

Revenue from Contracts with C_4

Revenue from Contracts with Customers - Remaining Performance Obligation (Details) $ in Thousands	Sep. 30, 2018USD ($)
Revenue from Contract with Customer [Abstract]
Remaining performance obligations	$ 249,695
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2018-10-01
Revenue from Contract with Customer [Abstract]
Remaining performance obligations	$ 85,439
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Performance obligations expected to be satisfied, expected timing	3 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-01-01
Revenue from Contract with Customer [Abstract]
Remaining performance obligations	$ 110,145
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Performance obligations expected to be satisfied, expected timing	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-01-01
Revenue from Contract with Customer [Abstract]
Remaining performance obligations	$ 44,906
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Performance obligations expected to be satisfied, expected timing	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01
Revenue from Contract with Customer [Abstract]
Remaining performance obligations	$ 1,073
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Performance obligations expected to be satisfied, expected timing	1 year

Revenue from Contracts with C_5

Revenue from Contracts with Customers - Contract with Client (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2018	Jan. 01, 2018	Dec. 31, 2017
Disaggregation of Revenue
Net receivables	$ 73,258		$ 67,714
Contract liability with customer	10,100	$ 5,400
Increase in contract liability from freight billing	14,000
Revenue from contract liability	9,300
Contracts with customer
Disaggregation of Revenue
Net receivables	$ 71,900	$ 66,200

Related Party Transactions (Nar

Related Party Transactions (Narratives) (Details) $ in Thousands	Apr. 26, 2018USD ($)	Sep. 30, 2018USD ($)	Sep. 30, 2018USD ($)	Sep. 30, 2017USD ($)contract	Dec. 31, 2017USD ($)
Related party transactions
Repayments of long-term debt			$ 273,636	$ 846,500
Loan receivable due from Archrock		$ 53,500	53,500		$ 0
Interest income from notes receivable		$ 700	1,300
Archrock
Related party transactions
Amount contributed by related party related to completion of overhauls on compression equipment			$ 1,700	3,900
Distributions recorded related to differences in net book value of compressor units exchanged to our assets transferred to related party				$ 2,100
Number of customer contracts included in transfers | contract				0
Revolving Credit Facility | Credit Facility | Archrock
Related party transactions
Repayments of long-term debt	$ 63,200

Related Party Transactions - Tr

Related Party Transactions - Transfers (Details) - Archrock $ in Thousands	9 Months Ended
	Sep. 30, 2017USD ($)compressor_unithp
Related party transactions
Number of compressor units transferred to a related party | compressor_unit	199
Horsepower of compressor units transferred to related party | hp	109,800
Net book value of compressor units transferred to related party | $	$ 47,824
Number of compressor units transferred by related party | compressor_unit	170
Horsepower of compressor units transferred by related party | hp	99,500
Net book value of compressor units transferred by related party | $	$ 45,664

Related Party Transactions - Ag

Related Party Transactions - Aggregate Cost and Accumulated Depreciation (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Related party transactions
Accumulated depreciation	$ 994,422	$ 953,325
Archrock | Equipment on lease to Archrock
Related party transactions
Aggregate cost	40,212	3,560
Accumulated depreciation	5,783	272
Archrock | Equipment on lease from Archrock
Related party transactions
Aggregate cost	67,048	224
Accumulated depreciation	$ 33,337	$ 34

Related Party Transactions - Re

Related Party Transactions - Revenue From Related Party (Details) - Archrock - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Related party transactions
Revenue	$ 984	$ 356
Cost of sales	$ 1,924	$ 719

Contract Costs (Details)

Contract Costs (Details) - USD ($)	3 Months Ended	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2018	Sep. 30, 2017	Jan. 01, 2018	Dec. 31, 2017
Disaggregation of Revenue
Contract costs	$ 29,531,000	$ 29,531,000		$ 16,316,000	$ 0
Capitalized contract, term		36 months
Amortization of contract costs		$ 7,962,000	$ 0
Impairment loss on customer contracts	0	0
Sales Commissions
Disaggregation of Revenue
Contract costs	3,300,000	3,300,000		2,000,000
Amortization of contract costs	400,000	900,000
Freight and Mobilization
Disaggregation of Revenue
Contract costs	26,200,000	26,200,000		$ 14,300,000
Amortization of contract costs	$ 2,800,000	$ 7,100,000

Long-Term Debt - Schedule of Lo

Long-Term Debt - Schedule of Long-term Debt (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Long-Term Debt
Long-term debt	$ 1,515,679	$ 1,361,053
Senior Notes | 6% senior notes due April 2021
Long-Term Debt
Long-term debt, gross	350,000	350,000
Less: Debt discount, net of amortization	(1,977)	(2,523)
Less: Deferred financing costs, net of amortization	(2,568)	(3,338)
Long-term debt	$ 345,455	344,139
Interest rate (as a percent)	6.00%
Senior Notes | 6% senior notes due October 2022
Long-Term Debt
Long-term debt, gross	$ 350,000	350,000
Less: Debt discount, net of amortization	(2,938)	(3,441)
Less: Deferred financing costs, net of amortization	(3,338)	(3,951)
Long-term debt	$ 343,724	342,608
Interest rate (as a percent)	6.00%
Revolving Credit Facility | Credit Facility
Long-Term Debt
Long-term debt	$ 826,500	$ 674,306
Interest rate (as a percent)	6.00%

Long-Term Debt - Credit Facilit

Long-Term Debt - Credit Facility (Details) - USD ($)	Apr. 26, 2018	Mar. 31, 2017	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Mar. 31, 2018	Dec. 31, 2017
Long-Term Debt
Payments for debt issuance costs					$ 3,332,000	$ 14,855,000
Loss on extinguishment of debt			$ 0	$ 0	0	291,000
Repayments of long-term debt					273,636,000	846,500,000
Letters of credit outstanding			$ 15,400,000		$ 15,400,000
Revolving Credit Facility
Long-Term Debt
Transaction costs	$ 3,300,000
Weighted average interest rate (percentage)			5.50%		5.50%			4.80%
Commitment fees			$ 600,000	$ 600,000	$ 1,700,000	$ 1,500,000
Revolving Credit Facility | Credit Facility
Long-Term Debt
Debt instrument term					5 years
Maximum borrowing capacity	1,250,000,000		$ 1,250,000,000		$ 1,250,000,000		$ 1,100,000,000
Interest rate (as a percent)			6.00%		6.00%
Payments for debt issuance costs		$ 14,900,000
Letters of credit outstanding	15,400,000
Line of credit remaining borrowing capacity			$ 408,100,000		$ 408,100,000
Revolving Credit Facility | Credit Facility | Maximum
Long-Term Debt
Line of credit remaining borrowing capacity			$ 324,000,000		$ 324,000,000
Revolving Credit Facility | Credit Facility | Archrock
Long-Term Debt
Repayments of long-term debt	63,200,000
Revolving Credit Facility | Term loan facility due May 2018
Long-Term Debt
Debt issuance cost expensed		600,000
Loss on extinguishment of debt		$ 300,000
Letter of credit | Credit Facility
Long-Term Debt
Maximum borrowing capacity	$ 50,000,000						$ 25,000,000
Line of Credit | Base Rate
Long-Term Debt
Spread on variable rate					3.20%

Long-Term Debt - Debt Ratios (D

Long-Term Debt - Debt Ratios (Details)	6 Months Ended	9 Months Ended	12 Months Ended		21 Months Ended
	Jun. 30, 2020	Sep. 30, 2018	Dec. 31, 2019	Dec. 31, 2018	Mar. 30, 2022
Forecasted | Revolving Credit Facility | Conditional Event
Line of Credit Facility
Total debt to EBITDA ratio					5.5
Exterran Partners LP
Line of Credit Facility
EBITDA to total interest expenses ratio		2.5
Senior secured debt to EBITDA ratio		3.5
Exterran Partners LP | Forecasted
Line of Credit Facility
Total debt to EBITDA ratio	5.5		5.75	5.95	5.25

Long-Term Debt - Senior Notes (

Long-Term Debt - Senior Notes (Details)	Sep. 30, 2018USD ($)
Debt Disclosure [Abstract]
Amount of independent assets or operations	$ 0

Partners' Capital (Narratives)

Partners' Capital (Narratives) (Details) $ / shares in Units, $ in Thousands	Oct. 29, 2018USD ($)$ / shares	Apr. 26, 2018shares	Apr. 25, 2018shares	Aug. 31, 2017USD ($)shares	Sep. 30, 2018USD ($)$ / sharesshares	Sep. 30, 2017USD ($)shares	Dec. 31, 2017shares
Partners' Equity, Allocations and Cash Distributions
Ownership interest held by public unitholders in the reporting entity (as a percent)			57.00%
General partner units, equivalent units outstanding (in units)					1,422,458		1,421,768
Issuance of general partner units | $					$ 9
Distribution per common unit (in dollars per unit) | $ / shares					$ 0.7492
Distributions to unitholders | $					$ 53,717	$ 58,690
Subsequent Event
Partners' Equity, Allocations and Cash Distributions
Distribution per common unit (in dollars per unit) | $ / shares	$ 0.2432
Authorized distributions to limited partnership, amount | $	$ 17,400
Partners' Capital Common Units
Partners' Equity, Allocations and Cash Distributions
Shares issued (shares)				4,600,000		4,600,000
Proceeds from the issuance of common stock | $				$ 60,300		$ 60,291
Partners' Capital Common Units | Over-allotment option
Partners' Equity, Allocations and Cash Distributions
Shares issued (shares)				600,000
Partners' Capital General Partner Units
Partners' Equity, Allocations and Cash Distributions
Proceeds from the issuance of common stock | $						$ 60,291
Units issued in connection with acquisition (in units)				93,163	690	94,506
Issuance of general partner units | $					$ 9	$ 1,305
Archrock
Partners' Equity, Allocations and Cash Distributions
Common units owned (in units)			29,064,637
General partner units, equivalent units outstanding (in units)			1,422,458
Archrock | Archrock Partners, L.P
Partners' Equity, Allocations and Cash Distributions
General partner's ownership interest in partnership (as a percent)			43.00%
Archrock | Partners' Capital Common Units
Partners' Equity, Allocations and Cash Distributions
General partner units interest (as a percentage)				2.00%
Issuance of general partner units | $				$ 1,300
Common stock
Partners' Equity, Allocations and Cash Distributions
Share conversion rate		1.40
Archrock | Common stock
Partners' Equity, Allocations and Cash Distributions
Business acquisition, shares issued (shares)		57,600,000
Business acquisition, shares acquired (shares)		41,200,000

Unit-Based Compensation - Long-

Unit-Based Compensation - Long-term Incentive Plan (Details) - Phantom Units	9 Months Ended
	Sep. 30, 2018$ / sharesshares
Long-Term Incentive Plan
Unit-Based Compensation
Vested (in units) | shares	53,091
Vested (in dollars per unit) | $ / shares	$ 11.24
First anniversary vesting
Unit-Based Compensation
Vesting percentage	33.33%
Second anniversary vesting
Unit-Based Compensation
Vesting percentage	33.33%
Third anniversary vesting
Unit-Based Compensation
Vesting percentage	33.33%

Derivatives - Interest Rate Ris

Derivatives - Interest Rate Risk (Details) - Derivatives designated as hedging instruments - USD ($) $ in Millions	Sep. 30, 2018	Aug. 31, 2017
Interest rate swaps
Accounting for Derivatives
Notional amount of interest rate swaps	$ 500
May 2,019
Accounting for Derivatives
Notional amount of interest rate swaps	100
May 2,020
Accounting for Derivatives
Notional amount of interest rate swaps	100
March 2,022
Accounting for Derivatives
Notional amount of interest rate swaps	$ 300	$ 300

Derivatives - Interest Rate R_2

Derivatives - Interest Rate Risk (Narratives) (Details) - Derivatives designated as hedging instruments - USD ($) $ in Millions	Sep. 30, 2018	Aug. 31, 2017
Interest rate swaps
Accounting for Derivatives
Deferred gain to be reclassified during next 12 months	$ 3.6
Notional amount of interest rate swaps	$ 500
Weighted average effective fixed interest rate on interest rate swaps (as a percent)	1.80%
March 2,022
Accounting for Derivatives
Notional amount of interest rate swaps	$ 300	$ 300
Derivative liability, fair value		$ 0.7

Derivatives - Effect on Derivat

Derivatives - Effect on Derivative Instruments on the Balance Sheet (Details) - Derivatives designated as hedging instruments - Interest rate swaps - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Accounting for Derivatives
Derivative asset, net	$ 13,079	$ 4,542
Current portion of interest rate swaps
Accounting for Derivatives
Derivative asset	3,592	186
Other long-term assets
Accounting for Derivatives
Derivative asset	9,487	4,490
Current portion of interest rate swaps
Accounting for Derivatives
Derivative liability	$ 0	$ (134)

Derivatives - Effect on Deriv_2

Derivatives - Effect on Derivative Instruments on the Income Statement (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Effect of derivative instruments on results of operations
Pre-tax gain recognized in other comprehensive income (loss)	$ 1,642	$ 1,919	$ 8,583	$ 2,282
Interest expense, net
Effect of derivative instruments on results of operations
Pre-tax gain (loss) reclassified from accumulated other comprehensive income (loss) into interest expense, net	$ 429	$ (652)	$ (20)	$ (2,427)

Derivatives - Derivative Gain (

Derivatives - Derivative Gain (Loss) Recognized in Income Statement (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Effect of derivative instruments on results of operations
Interest expense, net	$ 22,767	$ 21,839	$ 66,918	$ 63,361
Accumulated Other Comprehensive Income (Loss) | Reclassification out of Accumulated Other Comprehensive Income
Effect of derivative instruments on results of operations
Interest expense, net	$ 429		$ 582

Fair Value Measurements (Detail

Fair Value Measurements (Details) - Recurring basis - Level 2 - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Fair value measurements
Interest rate swaps asset	$ 13,079	$ 4,676
Interest rate swaps liability	$ 0	$ (134)

Fair Value Measurements (Narrat

Fair Value Measurements (Narratives) (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2018	Dec. 31, 2017
Nonrecurring basis | Level 3
Fair value measurements
Impaired long-lived assets	$ 0.8	$ 1.8
Impaired long-lived assets
Fair value measurements
Weighted average disposal period used in estimation of the fair value of the impaired long-lived assets	4 years

Fair Value Measurements - Fair

Fair Value Measurements - Fair Value of Debt (Details) - Fixed Rate Debt - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Carrying Amount
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Debt	$ 689,179	$ 686,747
Estimate of Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Debt	$ 706,000	$ 702,000

Long-Lived Asset Impairment (De

Long-Lived Asset Impairment (Details) hp in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018USD ($)compressor_unithp	Sep. 30, 2017USD ($)compressor_unithp	Sep. 30, 2018USD ($)compressor_unithp	Sep. 30, 2017USD ($)compressor_unithp
Long-lived asset impairment
Impairment recorded on idle compressor units retired from the active fleet	$ 3,673	$ 5,368	$ 10,585	$ 14,659
Idle compressor units
Long-lived asset impairment
Idle compressor units retired from the active fleet (compressors) | compressor_unit	35	45	140	150
Horsepower of idle compressor units retired from the active fleet (horsepower) | hp	14	18	44	53
Impairment recorded on idle compressor units retired from the active fleet	$ 3,673	$ 5,368	$ 10,585	$ 14,659

Income Taxes (Narratives) (Deta

Income Taxes (Narratives) (Details) $ in Millions	Sep. 30, 2018USD ($)
Income Tax Disclosure [Abstract]
Potential decrease in unrecognized tax benefit	$ 0.9

Commitments and Contingencies (

Commitments and Contingencies (Details) $ in Millions	9 Months Ended
	Sep. 30, 2018USD ($)caseclaim	Dec. 31, 2017USD ($)
Loss Contingencies
Accrual for income tax liability | $	$ 2.7	$ 1.6
Number of pending claims | case	2
Number of claims settled	3
Number of claims appealed	3
Judge
Loss Contingencies
Number of claims settled	2