Archrock Partners (APLP) 10-K 20 Feb 19 2018 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2018	Feb. 19, 2019	Jun. 30, 2018
Document and Entity Information
Entity Registrant Name	Archrock Partners, L.P.
Entity Central Index Key	1,367,064
Document Type	10-K
Document Period End Date	Dec. 31, 2018
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Entity Current Reporting Status	Yes
Entity Filer Category	Non-accelerated Filer
Entity Public Float			$ 0
Entity Common Stock, Shares Outstanding		70,231,036
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	FY
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Shell Company	false
Entity Emerging Growth Company	false
Entity Small Business	false

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Current assets:
Cash	$ 264	$ 8,078
Accounts receivable, trade, net of allowance of $1,253 and $1,296, respectively	80,606	67,714
Tax refund receivable	14,000	0
Derivative asset - current	3,185	186
Accrued interest on loan receivable due from Archrock	123	0
Total current assets	98,178	75,978
Property, plant and equipment	2,933,568	2,727,401
Accumulated depreciation	(1,042,182)	(953,325)
Property, plant and equipment, net	1,891,386	1,774,076
Intangible assets, net	45,839	60,747
Contract costs	32,220	0
Loan receivable due from Archrock	20,000	0
Other long-term assets	17,801	19,401
Total assets	2,105,424	1,930,202
Current liabilities:
Accounts payable, trade	10,646	18,368
Accrued liabilities	10,129	7,597
Deferred revenue	9,577	1,299
Accrued interest	11,999	12,972
Due to Archrock, net	17,251	4,683
Derivative liability - current	0	134
Total current liabilities	59,602	45,053
Long-term debt	1,529,501	1,361,053
Other long-term liabilities	9,175	9,356
Total liabilities	1,598,278	1,415,462
Commitments and contingencies (Note 17)
Partners’ capital:
Common units: 70,231,036 and 70,310,590 issued, respectively	488,209	501,023
General partner units: 1,422,458 and 1,421,768 issued and outstanding, respectively	11,630	11,582
Accumulated other comprehensive income	7,307	4,476
Treasury units: 113,609 common units at December 31, 2017	0	(2,341)
Total partners’ capital	507,146	514,740
Total liabilities and partners’ capital	$ 2,105,424	$ 1,930,202

CONSOLIDATED BALANCE SHEETS (Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Statement of Financial Position [Abstract]
Accounts receivable, trade, allowance (in dollars)	$ 1,253	$ 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 (in units)	0	113,609

CONSOLIDATED STATEMENTS OF OPER

CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Statement [Abstract]
Revenue	$ 612,358	$ 557,503	$ 562,360
Cost of sales (excluding depreciation and amortization)	244,576	229,355	209,411
Selling, general and administrative	70,030	82,035	79,717
Depreciation and amortization	136,757	143,848	153,741
Long-lived asset impairment	13,727	19,106	46,258
Restructuring charges	0	0	7,309
Interest expense, net	90,313	84,291	77,863
Debt extinguishment loss	0	291	0
Merger-related costs	2,718	1	0
Other income, net	(3,521)	(4,385)	(2,594)
Income (loss) before income taxes	57,758	2,961	(9,345)
Provision for income taxes	475	3,382	1,412
Net income (loss)	$ 57,283	$ (421)	$ (10,757)

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ 57,283	$ (421)	$ (10,757)
Other comprehensive income:
Interest rate swap gain, net of reclassifications to earnings	2,604	8,207	1,388
Amortization of terminated interest rate swaps	227	439	0
Total other comprehensive income	2,831	8,646	1,388
Comprehensive income (loss)	$ 60,114	$ 8,225	$ (9,369)

CONSOLIDATED STATEMENTS OF PART

CONSOLIDATED STATEMENTS OF PARTNERS' CAPITAL - USD ($) $ in Thousands	Total	March 2016 Acquisition	Archrock	Treasury Units	Accumulated Other Comprehensive Income (Loss)	Common Units	Common UnitsMarch 2016 Acquisition	Common UnitsArchrock	General Partner Units	General Partner UnitsMarch 2016 Acquisition	General Partner UnitsArchrock
Beginning balance at Dec. 31, 2015	$ 547,996			$ (1,794)	$ (5,558)	$ 538,197			$ 17,151
Beginning balance (in units) at Dec. 31, 2015				(74,888)		59,796,514			1,209,562
Increase (Decrease) in Partners' Capital
Issuance of common units for vesting of phantom units (in units)						70,560
Treasury units purchased	(98)			$ (98)
Treasury units purchased (in units)				(11,907)
Units issued in connection with acquisition		$ 1,836	$ 67,708				$ 1,799	$ 66,364		$ 37	$ 1,344
Units issued in connection with acquisition (in units)							257,000	5,482,581		5,205	111,040
Issuance of general partner units									$ 8
Issuance of general partner units (in units)									1,158
Contribution (distribution) of capital, net	5,108					$ 4,924			$ 184
Cash distributions ($1.1400 per common unit)	(92,220)					(85,736)			(6,484)
Unit-based compensation expense	1,204					1,204
Comprehensive income
Net income (loss)	(10,757)					(10,544)			(213)
Interest rate swap gain, net of reclassifications to earnings	1,388				1,388
Ending balance at Dec. 31, 2016	522,173			$ (1,892)	(4,170)	$ 516,208			$ 12,027
Ending 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)						103,935
Treasury units purchased	(449)			$ (449)
Treasury units purchased (in units)				(26,814)
Issuance of common units						$ 60,291			$ 60,291
Issuance of common units (in units)						4,600,000
Issuance of general partner units									$ 1,307
Issuance of general partner units (in units)									94,803
Contribution (distribution) of capital, net	1,280					$ 1,456			$ (176)
Cash distributions ($1.1400 per common unit)	(79,149)					(77,582)			(1,567)
Unit-based compensation expense	1,062					1,062
Comprehensive income
Net income (loss)	(421)					(412)			(9)
Interest rate swap gain, net of reclassifications to earnings	8,207				8,207
Amortization of terminated interest rate swaps	439				439
Ending balance at Dec. 31, 2017	514,740			$ (2,341)	4,476	$ 501,023			$ 11,582
Ending balance (in units) at Dec. 31, 2017				(113,609)		70,310,590			1,421,768
Increase (Decrease) in Partners' Capital
Cumulative-effect adjustment | ASU 2014-09	12,714					$ 12,462			$ 252
Cumulative-effect adjustment | ASU 2017-12	383					$ 375			8
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
Issuance of general partner units (in units)									690
Contribution (distribution) of capital, net	4,216					$ 4,162			$ 54
Distribution of capital - excess of fair market value of equipment purchased from Archrock over equipment sold to Archrock	(13,951)					(13,951)
Cash distributions ($1.1400 per common unit)	(71,143)					(69,731)			(1,412)
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)	57,283					$ 56,146			1,137
Interest rate swap gain, net of reclassifications to earnings	2,604				2,604
Amortization of terminated interest rate swaps	227				227
Ending balance at Dec. 31, 2018	$ 507,146			$ 0	$ 7,307	$ 488,209			$ 11,630
Ending balance (in units) at Dec. 31, 2018				0		70,231,036			1,422,458

CONSOLIDATED STATEMENTS OF PA_2

CONSOLIDATED STATEMENTS OF PARTNERS' CAPITAL (Parenthetical) - $ / shares	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Statement of Partners' Capital [Abstract]
Distributions (usd per unit)	$ 0.9924	$ 1.14000	$ 1.4275

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Cash flows from operating activities:
Net income (loss)	$ 57,283,000	$ (421,000)	$ (10,757,000)
Adjustments to reconcile net income (loss) to cash provided by operating activities:
Depreciation and amortization	136,757,000	143,848,000	153,741,000
Long-lived asset impairment	13,727,000	19,106,000	46,258,000
Amortization of deferred financing costs	5,881,000	5,624,000	4,492,000
Amortization of debt discount	1,410,000	1,325,000	1,245,000
Amortization of terminated interest rate swaps	227,000	439,000	0
Debt extinguishment loss	0	291,000	0
Interest rate swaps	(131,000)	2,183,000	1,590,000
Unit-based compensation expense	314,000	1,062,000	1,203,000
Provision for doubtful accounts	1,105,000	4,104,000	2,672,000
Gain on sale of property, plant and equipment	(3,200,000)	(4,262,000)	(3,585,000)
Loss on non-cash consideration in March 2016 Acquisition	0	0	635,000
Deferred income tax provision (benefit)	(29,000)	3,384,000	1,444,000
Amortization of contract costs	11,709,000	0	0
Deferred revenue recognized in earnings	(13,672,000)	0	0
Changes in assets and liabilities, net of acquisitions:
Accounts receivable, trade	(20,371,000)	(1,919,000)	12,537,000
Contract costs	(27,612,000)	0	0
Other assets and liabilities	2,335,000	4,263,000	554,000
Deferred revenue	17,973,000	54,000	1,000,000
Net cash provided by operating activities	183,706,000	179,081,000	213,029,000
Cash flows from investing activities:
Capital expenditures	(287,349,000)	(179,319,000)	(62,345,000)
Proceeds from sale of property, plant and equipment	26,291,000	31,010,000	28,858,000
Proceeds from insurance	252,000	252,000	0
Payment for March 2016 Acquisition	0	0	(13,779,000)
(Borrowings to) repayments from Archrock, net	(20,000,000)	0	0
Net cash used in investing activities	(280,806,000)	(148,057,000)	(47,266,000)
Cash flows from financing activities:
Proceeds from borrowings of long-term debt	603,830,000	919,000,000	257,500,000
Repayments of long-term debt	(438,636,000)	(904,194,000)	(328,500,000)
Payments for debt issuance costs	(3,332,000)	(14,855,000)	(1,719,000)
Proceeds from settlement of interest rate swaps that include financing elements	190,000
Payments for settlement of interest rate swaps that include financing elements		(1,785,000)	(3,058,000)
Distributions to unitholders	(71,143,000)	(79,149,000)	(92,220,000)
Net proceeds from issuance of common units	0	60,291,000	0
Net proceeds from issuance of general partner units	9,000	1,307,000	45,000
Purchases of treasury units	(250,000)	(449,000)	(98,000)
Increase (decrease) in amounts due to Archrock, net	(1,382,000)	(3,329,000)	2,032,000
Net cash provided by (used in) financing activities	89,286,000	(23,163,000)	(166,018,000)
Net increase (decrease) in cash	(7,814,000)	7,861,000	(255,000)
Cash at beginning of period	8,078,000	217,000	472,000
Cash at end of period	264,000	8,078,000	217,000
Supplemental disclosure of cash flow information:
Cash paid for interest	85,677,000	76,002,000	73,738,000
Income taxes refunded, net	(469,000)	(141,000)	(71,000)
Supplemental disclosure of non-cash transactions:
Accrued capital expenditures	10,646,000	18,368,000	2,934,000
Non-cash capital contribution from limited and general partner	2,720,000	5,247,000	1,163,000
Non-cash capital distribution to Archrock	(13,951,000)	0	0
Contract operations equipment acquired/exchanged, net	1,496,000		70,310,000
Contract operations equipment acquired/exchanged, net		(3,967,000)
Non-cash consideration in March 2016 Acquisition	0	0	3,165,000
Common units issued in March 2016 Acquisition	0	0	1,799,000
Intangible assets allocated in contract operations acquisitions	0	0	1,147,000
Non-cash capital distribution due to contract operations acquisitions	0	0	(17,292,000)
Common units issued in contract operations acquisitions	0	0	85,112,000
General partner units issued in contract operations acquisitions	$ 0	$ 0	$ 1,687,000

Organization and Summary of Sig

Organization and Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2018
Accounting Policies [Abstract]
Organization and Summary of Significant Accounting Policies	1. Organization and Summary of Significant Accounting Policies Organization We are a Delaware limited partnership formed in June 2006. On April 26, 2018, Archrock completed the acquisition of all of our outstanding common units that it did not already own and, as a result, we became its wholly-owned subsidiary. See Note 10 (“Partners’ Capital”) for further details of the Merger. We are a leading provider of natural gas compression services to customers in the oil and natural gas industry throughout the U.S. Our business supports a must-run service that is essential to the production, processing, transportation and storage of natural gas. Our geographic diversity and large fleet of natural gas compression equipment enable us to provide reliable contract operations services to our customers throughout the U.S. We operate in one segment solely within the U.S. Significant Accounting Policies Principles of Consolidation and Use of Estimates The accompanying consolidated financial statements include us and our subsidiaries. All intercompany accounts and transactions have been eliminated in consolidation. Certain prior year amounts have been reclassified to conform to the current year presentation. The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amount of assets, liabilities, revenues, expenses and disclosures of contingent assets and liabilities. Because of the inherent uncertainties in this process, actual future results could differ from those expected as of the reporting date. Management believes that the estimates and assumptions used are reasonable. Revenue Recognition As a result of the Revenue Recognition Update adopted January 1, 2018, 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. In our contract operations business, natural gas compression service revenue is recognized over time and revenue associated with billable maintenance on our natural gas compression equipment is recognized at a point in time. 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. Under previous guidance, contract operations revenue was recognized when earned, which generally occurs monthly when the service is provided under our customer contracts. Concentrations of Credit Risk Financial instruments that potentially subject us to concentrations of credit risk consist of trade accounts receivable. Trade accounts receivable are due from companies of varying size engaged principally in oil and natural gas activities throughout the U.S. We review the financial condition of customers prior to extending credit and generally do not obtain collateral for trade receivables. Payment terms are on a short-term basis and in accordance with industry practice. We consider this credit risk to be limited due to these companies’ financial resources, the nature of services we provide and the terms of our contract operations customer service agreements. During the years ended December 31, 2018 , 2017 and 2016 , Williams Partners accounted for approximately 14% , 16% and 17% of our revenue, respectively. Additionally, during the years ended December 31, 2018 , 2017 and 2016 , Anadarko accounted for 9% , 10% and 10% , respectively, of our revenue. No other single customer accounted for 10% or more of our revenue during these years. As of December 31, 2018 , trade receivables outstanding from Anadarko and Williams Partners were 20% and 16% , respectively, of our total trade accounts receivable balance. As of December 31, 2017 , trade receivables outstanding from Anadarko and Williams Partners were 13% and 22% , respectively, of our total trade accounts receivable balance. Outstanding accounts receivable are reviewed regularly for non-payment indicators and allowances for doubtful accounts are recorded based upon management’s estimate of collectability at each balance sheet date. During the years ended December 31, 2018 , 2017 and 2016 , we recorded bad debt expense of $1.1 million , $4.1 million and $2.7 million , respectively. Property, Plant and Equipment Property, plant and equipment includes compression equipment that is recorded at cost and depreciated using the straight-line method over their estimated useful lives. For compression equipment, depreciation begins with the first compression service. The estimated useful life for compression equipment is 15 to 30 years. Major improvements that extend the useful life of a compressor unit are capitalized and depreciated over the estimated useful life of the major improvement, up to seven years. Repairs and maintenance are expensed as incurred. When property, plant and equipment is sold, retired or otherwise disposed of, the gain or loss is recorded in other (income) loss, net. Depreciation expense during the years ended December 31, 2018 , 2017 and 2016 was $121.9 million , $127.9 million and $138.0 million , respectively. Long-Lived Assets 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. An impairment loss exists when estimated undiscounted cash flows expected from the use of the asset and its eventual disposition are less than its carrying amount. Impairment losses are recognized in the period in which the impairment occurs and represent the excess of the asset carrying value over its fair value. Identifiable intangibles are amortized over the estimated useful life of the asset. Due To/From Affiliates, Net We have receivables and payables with Archrock. A valid right of offset exists related to the receivables and payables with our affiliates and as a result, we present such amounts on a net basis in our consolidated balance sheets. The transactions reflected in due to/from affiliates, net, primarily consist of centralized cash management activities between us and Archrock. Because these balances are treated as short-term borrowings between us and Archrock, serve as a financing and cash management tool to meet our short-term operating needs, are large, turn over quickly and are payable on demand, we present borrowings and repayments with our affiliates on a net basis within the consolidated statements of cash flows. Net receivables from our affiliates are considered advances and changes are presented as investing activities in the consolidated statements of cash flows. Net payables due to our affiliates are considered borrowings and changes are presented as financing activities in the consolidated statements of cash flows. Income Taxes As a partnership, all income, gains, losses, expenses, deductions and tax credits we generate generally flow through to our unitholders. However, some states impose an entity-level income tax on partnerships, including us. We account for income taxes under the asset and liability method which requires the recognition of deferred tax assets and liabilities for the expected future tax consequences of events included in the financial statements. Under this method, deferred tax assets and liabilities are determined based on the differences between the financial statements and the tax basis of assets and liabilities using enacted tax rates in effect for the year in which the differences are expected to reverse. The effect of a change in tax rate on deferred tax assets and liabilities is recognized in income in the period that includes the enactment date. We record uncertain tax positions in accordance with the accounting standard on income taxes under a two-step process whereby (1) we determine whether it is more likely than not that the tax positions will be sustained based on the technical merits of the position and (2) for those tax positions that meet the more-likely-than-not recognition threshold, we recognize the largest amount of tax benefit that is greater than 50 percent likely to be realized upon ultimate settlement with the related tax authority. Hedging and Use of Derivative Instruments We use derivative instruments to manage our exposure to fluctuations in the variable interest rate of the Credit Facility and thereby minimize the risks and costs associated with financial activities. We do not use derivative instruments for trading or other speculative purposes. We record interest rate swaps on the balance sheet as either derivative assets or derivative liabilities measured at their fair value. The fair value of our derivatives is based on the income approach (discounted cash flow) using market observable inputs, including LIBOR forward curves. Changes in the fair value of the derivatives designated as cash flow hedges are 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, the same statement of operations line item to which the earnings effect of the hedged item is recorded. To qualify for hedge accounting treatment, we must formally document, designate and assess the effectiveness of the transactions. If the necessary correlation ceases to exist or if the anticipated transaction is no longer probable, we would discontinue hedge accounting and apply mark-to-market accounting. Amounts paid or received from interest rate swap agreements are charged or credited to interest expense and matched with the cash flows and interest expense of the debt being hedged, resulting in an adjustment to the effective interest rate.

Recent Accounting Developments

Recent Accounting Developments	12 Months Ended
	Dec. 31, 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. As a result of the adoption of ASU 2016-15 we reclassified $0.3 million of insurance proceeds from net cash provided by operating activities to net cash used in investing activities in our consolidated statement of cash flows during the year ended December 31, 2017 . There was no impact to our consolidated statement of cash flows during the year ended December 31, 2016 . 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 consolidated balance sheet and consolidated statements of operations (in thousands): December 31, 2018 Balance Sheet As Reported Balance Excluding the Impact of the Revenue Recognition Update Effect of Change Assets Accounts receivable, trade $ 80,606 $ 80,291 $ 315 Contract costs 32,220 — 32,220 Liabilities Accrued liabilities $ 10,129 $ 9,833 $ 296 Deferred revenue 9,577 2,002 7,575 Other long-term liabilities 9,175 9,187 (12 ) Equity Common units $ 488,209 $ 464,104 $ 24,105 General partner units 11,630 11,059 571 —————— (1) Represents the impact of the Revenue Recognition Update on net income attributable to noncontrolling interest which was reclassed to additional paid-in capital pursuant to the Merger. December 31, 2018 Statement of Operations As Reported Balance Excluding the Impact of the Revenue Recognition Update Effect of Change Revenue $ 612,358 $ 616,311 $ (3,953 ) Cost of sales (excluding depreciation and amortization) 244,576 258,808 (14,232 ) Selling, general and administrative 70,030 71,701 (1,671 ) Provision for income taxes 475 487 (12 ) Net income (loss) 57,283 45,321 11,962 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. 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 including an option not to apply the recognition requirements to short term leases. 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. The July 2018 amendment also 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 Leases 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 evaluated the impact of the July 2018 amendment on our contract operations services agreements and have concluded that the services nonlease component is predominant, which results in the ongoing recognition following the Revenue Recognition Update guidance. In conjunction with our assessment of ASC Topic 842 Leases we established a cross-functional implementation team to identify our lease population and to assess changes to our internal control structure, business processes, systems and accounting policies necessary to implement the standard. Based on our review, we have determined that ASC Topic 842 Leases will not have an impact on our consolidated balance sheet or statement of operations because of the available practical expedients.

Revenue from Contracts with Cus

Revenue from Contracts with Customers	12 Months Ended
	Dec. 31, 2018
Revenue from Contract with Customer [Abstract]
Revenue from Contract with Customer	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): Year Ended December 31, 2018 0 - 1,000 horsepower per unit $ 220,413 1,001 - 1,500 horsepower per unit 253,919 Over 1,500 horsepower per unit 135,322 Other (1) 2,704 Total revenue (2) $ 612,358 —————— (1) Primarily relates to fees associated with Partnership-owned non-compressor equipment. (2) Includes $5.9 million 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. 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. 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 December 31, 2018 , we had $246.0 million of remaining performance obligations related to our contract compression service. This amount will be recognized through 2022 as follows (in thousands): 2019 2020 2021 2022 Total Remaining performance obligations $ 174,962 $ 56,866 $ 12,699 $ 1,503 $ 246,030 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 customers for the transport of compressor assets often result in a contract liability. As of December 31, and January 1, 2018 , our receivables from contracts with customers, net of allowance for doubtful accounts were $78.6 million and $66.2 million , respectively. As of December 31, and January 1, 2018 , our contract liabilities were $9.7 million and $5.4 million , respectively, which are included in deferred revenue and other long-term liabilities in our consolidated balance sheets. The increase in the contract liability balance during the year ended December 31, 2018 was due to the deferral of $18.0 million partially offset by $13.7 million recognized as revenue during the period, each primarily related to freight billings. 6. 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 December 31, and January 1, 2018, we recorded contract costs of $3.6 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 December 31, and January 1, 2018, we recorded contract costs of $28.6 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 year ended December 31, 2018 , we amortized $1.3 million related to commissions and $10.4 million related to freight and mobilization. During the year ended December 31, 2018 , there were no impairment losses recorded in relation to the costs capitalized.

Business Acquisitions

Business Acquisitions	12 Months Ended
	Dec. 31, 2018
Business Combinations [Abstract]
Business Acquisitions	4. Business Acquisitions November 2016 Contract Operations Acquisition In November 2016, we completed the November 2016 Contract Operations Acquisition whereby we acquired from Archrock contract operations customer service agreements with 63 customers and a fleet of 262 compressor units used to provide compression services under those agreements comprising approximately 147,000 horsepower, or approximately 4% (of then-available horsepower), of the combined U.S. contract operations business of Archrock and us. At the acquisition date, the acquired fleet assets had a net book value of $66.6 million , net of accumulated depreciation of $55.6 million . Total consideration for the transaction was $85.0 million excluding transaction costs. In connection with the acquisition, we issued 5.5 million common units to Archrock and 111,040 general partner units to our General Partner. During the year ended December 31, 2016, we incurred transaction costs of $0.4 million related to this acquisition which is reflected in other income, net in our consolidated statement of operations. In connection with this acquisition, we were allocated $1.1 million finite-life intangible assets associated with customer relationships of Archrock’s contract operations segment. The amounts allocated were based on the ratio of the fair value of the net assets transferred to us to the total fair value of Archrock’s contract operations segment. These intangible assets are being amortized through 2024 based on the present value of income expected to be realized from these intangible assets. Because we and Archrock are considered entities under common control, GAAP requires that we record the assets acquired and liabilities assumed from Archrock using Archrock’s historical cost basis in the assets and liabilities. The difference between the historical cost basis of the assets acquired and liabilities assumed and the purchase price is treated as either a capital contribution or distribution. As a result, we recorded a capital distribution of $17.3 million for the November 2016 Contract Operations Acquisition during the year ended December 31, 2016. An acquisition of a business from an entity under common control is generally accounted for under GAAP by the acquirer with retroactive application as if the acquisition date was the beginning of the earliest period included in the financial statements. Retroactive effect to the November 2016 Contract Operations Acquisition was impracticable because such retroactive application would have required significant assumptions in a prior period that cannot be substantiated. Accordingly, our financial statements include the assets acquired, liabilities assumed, revenue and direct operating expenses associated with the acquisition beginning on the date of the acquisition. However, the preparation of pro forma financial information allows for certain assumptions that do not meet the standards of financial statements prepared in accordance with GAAP. Unaudited Pro Forma Financial Information The unaudited pro forma financial information for the year ended December 31, 2016 has been included to give effect to the assets acquired in the November 2016 Contract Operations Acquisition. The November 2016 Contract Operations Acquisition is presented below as though this transaction occurred as of January 1, 2015. The unaudited pro forma financial information reflects the following: • our acquisition of certain contract operations customer service agreements, compression equipment and identifiable intangible assets from Archrock; and • our issuance of 5.5 million common units to Archrock and 111,040 general partner units to our General Partner. The pro forma financial information below is presented for informational purposes only and is not necessarily indicative of the results of operations that would have occurred had the transaction been consummated at the beginning of the period presented, nor is it necessarily indicative of future results. The pro forma financial information below was derived by adjusting our historical financial statements. The following table shows pro forma financial information for the year ended December 31, 2016 (in thousands, except per unit amount): Year ended December 31, 2016 Revenue $ 589,494 Net income 552 Basic and diluted income per common unit — March 2016 Acquisition In March 2016, we completed the March 2016 Acquisition whereby we acquired contract operations customer service agreements with four customers and a fleet of 19 compressor units used to provide compression services under those agreements comprising approximately 23,000 horsepower. The $18.8 million purchase price was funded with $13.8 million in borrowings under our Former Credit Facility, a non-cash exchange of 24 compressor units for $3.2 million and the issuance of 257,000 common units for $1.8 million . In connection with this acquisition, we issued and sold 5,205 general partner units to our General Partner in order to maintain its approximate 2% general partner interest in us. During the year ended December 31, 2016, we incurred transaction costs of $0.2 million related to the March 2016 Acquisition which is reflected in other income, net in our consolidated statement of operations. We accounted for the March 2016 Acquisition using the acquisition method which requires, among other things, assets acquired to be recorded at their fair value on the acquisition date. The following table summarizes the purchase price allocation based on estimated fair values of the acquired assets as of the acquisition date (in thousands): Fair Value Property, plant and equipment $ 14,929 Intangible assets 3,839 Purchase price $ 18,768 The acquired property, plant and equipment primarily consisted of compressor units that will be depreciated on a straight-line basis over an estimated average remaining useful life of 15 years . The amount of acquired finite-life intangible assets and their average useful lives were determined based on the period over which the assets are expected to contribute directly or indirectly to our future cash flows and consisted of the following (dollars in thousands): Amount Average Useful Life Contract-based intangible assets $ 3,839 2.3 years The results of operations attributable to the assets acquired in the March 2016 Acquisition have been included in our consolidated financial statements since the date of acquisition. Pro forma financial information is not presented for the March 2016 Acquisition as it is immaterial to our reported results.

Related Party Transactions

Related Party Transactions	12 Months Ended
	Dec. 31, 2018
Related Party Transactions [Abstract]
Related Party Transactions	5. 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 9 (“Long-Term Debt”) and Note 10 (“Partners’ Capital”) for further details of our pay down of the Archrock credit facility and the Merger, respectively. At December 31, 2018 , the balance of outstanding borrowings under the Revolving Loan Agreement was $20.0 million . During the year ended December 31, 2018 , we recorded $1.8 million of interest income earned on loans to Archrock under the Revolving Loan Agreement which was included in interest expense, net in our consolidated statements of operations. Omnibus Agreement Our Omnibus Agreement 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. Non-competition Under the Omnibus Agreement, subject to the provisions described below, Archrock has agreed not to offer or provide contract operations services to our contract operations services customers that are not also contract operations services customers of Archrock. Similarly, we have agreed not to offer or provide such services to Archrock’s contract operations services customers that are not also our contract operations services customers. Some of our customers are also Archrock’s contract operations services customers, which we refer to as overlapping customers. We and Archrock have agreed, subject to the exceptions described below, not to provide compression services to an overlapping customer at any site at which the other was providing such services to an overlapping customer on the date of the most recent Omnibus Agreement, such sites being referred to as a “Partnership Site” or an “Archrock Site,” respectively. Pursuant to the Omnibus Agreement, if an overlapping customer requests contract operations services at a Partnership Site or an Archrock Site, whether in addition to or in replacement of the contract operations services or equipment existing at such site on the date of the most recent Omnibus Agreement, we may provide those services if such overlapping customer is a Partnership customer and Archrock will be entitled to provide such services if such overlapping customer is an Archrock customer. Otherwise, any contract operations services provided to a Partnership customer will be provided by us and any such services provided to an Archrock customer will be provided by Archrock. Archrock also has agreed that new customers for contract operations services are for our account unless the new customer is unwilling to contract with us under our form of contract operations services agreement. In that case, Archrock may provide services to the new customer. A customer that is a customer only through the lease-takeover of contracts from an existing customer of either Archrock or ourselves is considered a new customer if it requests additional contract operations services in its own name. If we or Archrock enter into a contract operations services contract with a new customer, either we or Archrock, as applicable, will receive the protection of the applicable non-competition arrangements described above in the same manner as if such new customer had been a contract operations services customer of either us or Archrock on the date of the Omnibus Agreement. Indemnification for Environmental and Other Liabilities Under the Omnibus Agreement, Archrock has agreed to indemnify us, for a three -year period following each applicable asset acquisition from Archrock, against certain potential environmental claims, losses and expenses associated with the ownership and operation of the acquired assets that occur before the acquisition date. Archrock’s maximum liability for environmental indemnification obligations under the Omnibus Agreement cannot exceed $5.0 million and Archrock will not have any obligation under the environmental or any other indemnification until our aggregate losses exceed $250,000 . Archrock will have no indemnification obligations with respect to environmental claims made as a result of additions to or modifications of environmental laws promulgated after such acquisition date. We have agreed to indemnify Archrock against environmental liabilities occurring on or after the applicable acquisition date related to our assets to the extent Archrock is not required to indemnify us. Additionally, Archrock will indemnify us for losses attributable to title defects, retained assets and income taxes attributable to pre-closing operations. We will indemnify Archrock for all losses attributable to the post-closing operations of the assets contributed to us, to the extent not subject to Archrock indemnification obligations. For the years ended December 31, 2018 , 2017 and 2016 , there were no requests for indemnification by either party. 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 received is treated as a capital distribution or contribution. Lease and Sale of Compression Equipment with Archrock If Archrock determines in good faith that we or Archrock’s contract operations services business needs to lease or sell compression equipment between Archrock and us, the Omnibus Agreement permits such transactions if it will not cause us to breach any existing contracts, suffer a loss of revenue under an existing contract operations services contract or incur any unreimbursed costs. As consideration for the lease of compression equipment the transferee will agree to lease such compression equipment from the transferor. As consideration for the sale of compression equipment, the transferee will make a distribution to or receive a contribution from the transferor in an amount equal to the net book value of the compression equipment sold. Leases The following table summarizes the aggregate cost and accumulated depreciation of equipment on lease to and from Archrock (in thousands): December 31, 2018 2017 Equipment on lease to Archrock Aggregate cost $ 3,824 $ 3,560 Accumulated depreciation 164 272 Equipment on lease from Archrock Aggregate cost $ 5,040 $ 224 Accumulated depreciation 2,659 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): Year Ended December 31, 2018 2017 2016 Revenue $ 1,440 $ 708 $ 123 Cost of sales 2,797 1,008 270 Sales The following table summarizes compressor unit sales activity between Archrock and us (dollars in thousands): Year Ended December 31, 2018 Sold to Archrock Purchased from Archrock Compressor units 85 184 Horsepower 53,624 107,431 Net book value $ 38,441 $ 39,937 During the year ended December 31, 2018 , we recorded a capital contribution of $1.5 million related to the difference in net book value of the compression equipment sold to and acquired from Archrock. In addition, in accordance with the Omnibus Agreement, we recorded a capital distribution of $14.0 million which represented the net excess of the fair market value of the equipment purchased from Archrock over the equipment sold to Archrock. No customer contracts were included in these sales. Exchanges 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. The following table summarizes the like-kind exchange activity between Archrock and us in 2017 and 2016 prior to the enactment of the TCJA (dollars in thousands): Transferred to Archrock Transferred from Archrock Year Ended December 31, Year Ended December 31, 2017 2016 2017 2016 Compressor units 249 462 251 339 Horsepower 156,600 205,000 145,000 154,000 Net book value $ 78,856 $ 92,382 $ 74,874 $ 96,216 During the years ended December 31, 2017 and 2016 , we recorded capital distributions of $4.0 million and capital contributions of $3.8 million , respectively, related to the differences in net book value of exchanged compression equipment. No customer contracts were included in the exchanges. Transfer of Overhauls During the years ended December 31, 2018 , 2017 and 2016 , Archrock contributed to us $2.9 million , $5.2 million and $1.2 million , respectively, related to the completion of overhauls on compression equipment that was sold to us during 2018 or exchanged with us during 2017 and 2016 and where the overhauls were in progress on the date of the sale or exchange. 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. Included in our cost of sales during the years ended December 31, 2018 , 2017 and 2016 were $14.1 million , $17.3 million and $4.8 million , respectively, of indirect costs incurred by Archrock. Included in SG&A during the years ended December 31, 2018 , 2017 and 2016 were $66.6 million , $68.7 million and $68.8 million , respectively, of indirect costs incurred by Archrock.

Contract Costs

Contract Costs	12 Months Ended
	Dec. 31, 2018
Revenue from Contract with Customer [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): Year Ended December 31, 2018 0 - 1,000 horsepower per unit $ 220,413 1,001 - 1,500 horsepower per unit 253,919 Over 1,500 horsepower per unit 135,322 Other (1) 2,704 Total revenue (2) $ 612,358 —————— (1) Primarily relates to fees associated with Partnership-owned non-compressor equipment. (2) Includes $5.9 million 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. 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. 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 December 31, 2018 , we had $246.0 million of remaining performance obligations related to our contract compression service. This amount will be recognized through 2022 as follows (in thousands): 2019 2020 2021 2022 Total Remaining performance obligations $ 174,962 $ 56,866 $ 12,699 $ 1,503 $ 246,030 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 customers for the transport of compressor assets often result in a contract liability. As of December 31, and January 1, 2018 , our receivables from contracts with customers, net of allowance for doubtful accounts were $78.6 million and $66.2 million , respectively. As of December 31, and January 1, 2018 , our contract liabilities were $9.7 million and $5.4 million , respectively, which are included in deferred revenue and other long-term liabilities in our consolidated balance sheets. The increase in the contract liability balance during the year ended December 31, 2018 was due to the deferral of $18.0 million partially offset by $13.7 million recognized as revenue during the period, each primarily related to freight billings. 6. 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 December 31, and January 1, 2018, we recorded contract costs of $3.6 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 December 31, and January 1, 2018, we recorded contract costs of $28.6 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 year ended December 31, 2018 , we amortized $1.3 million related to commissions and $10.4 million related to freight and mobilization. During the year ended December 31, 2018 , there were no impairment losses recorded in relation to the costs capitalized.

Intangible Assets, net

Intangible Assets, net	12 Months Ended
	Dec. 31, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Intangible Assets, net	7. Intangible Assets, net Intangible assets include customer relationships and contracts associated with various business and asset acquisitions. The acquired intangible assets were recorded at fair value determined as of the acquisition date. For those intangible assets related to customer relationships acquired from Archrock, amounts were allocated to us based on the ratio of the fair value of the net assets transferred to us to the total fair value of Archrock’s contract operations business. Our intangible assets are being amortized over the period we expect to benefit from the assets. Intangible assets, net consisted of the following (in thousands): December 31, 2018 December 31, 2017 Gross Carrying Amount Accumulated Amortization Gross Carrying Amount Accumulated Amortization Customer related (9-25 year life) $ 56,707 $ (25,908 ) $ 56,707 $ (22,713 ) Contract based (5-7 year life) 64,556 (49,516 ) 68,395 (41,642 ) Intangible assets $ 121,263 $ (75,424 ) $ 125,102 $ (64,355 ) Amortization of intangible assets totaled $14.9 million , $15.9 million and $15.8 million during the years ended December 31, 2018 , 2017 and 2016 , respectively. Estimated future intangible amortization expense is as follows (in thousands): 2019 $ 11,623 2020 8,286 2021 3,541 2022 2,472 2023 2,334 Thereafter 17,583 Total $ 45,839

Accrued Liabilities

Accrued Liabilities	12 Months Ended
	Dec. 31, 2018
Payables and Accruals [Abstract]
Accrued Liabilities	8. Accrued Liabilities Accrued liabilities consisted of the following (in thousands): December 31, 2018 2017 Accrued income and other taxes (1) $ 6,187 $ 5,675 Accrued other liabilities 3,942 1,922 Accrued liabilities $ 10,129 $ 7,597 —————— (1) Represents accruals for taxes including ad valorem tax, sales tax and use tax.

Long-Term Debt

Long-Term Debt	12 Months Ended
	Dec. 31, 2018
Debt Disclosure [Abstract]
Long-Term Debt	Long-Term Debt Long-term debt consisted of the following (in thousands): December 31, 2018 2017 Credit Facility $ 839,500 $ 674,306 6% senior notes due April 2021 350,000 350,000 Less: Debt discount, net of amortization (1,789 ) (2,523 ) Less: Deferred financing costs, net of amortization (2,311 ) (3,338 ) 345,900 344,139 6% senior notes due October 2022 350,000 350,000 Less: Debt discount, net of amortization (2,766 ) (3,441 ) Less: Deferred financing costs, net of amortization (3,133 ) (3,951 ) 344,101 342,608 Long-term debt $ 1,529,501 $ 1,361,053 Credit Facility The Credit Facility 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 , it will instead mature on December 2, 2020 . In March 2017, we incurred $14.9 million in transaction costs related to the formation of the Credit Facility which were included in other long-term assets in our consolidated balance sheets and are being amortized over the term of the facility. Concurrent with entering into the Credit Facility, we terminated our Former Credit Facility, and all commitments under the facility, and repaid $648.4 million in borrowings and accrued and unpaid interest and fees outstanding. As a result of the termination, we expensed $0.6 million of unamortized deferred financing costs, which were included in interest expense in our consolidated statements of operations, and recorded a debt extinguishment loss of $0.3 million . 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 our subsidiaries, as a borrower under our Credit Facility and certain of our other subsidiaries as loan guarantors; and – amend the definition of “Borrowing Base” to include certain assets of ours and our subsidiaries. We incurred $3.3 million in transaction costs related to Amendment No. 1 which were included in other long-term assets in our consolidated balance sheet and are being amortized over the term of the Credit Facility. Subject to certain conditions, including the approval by the lenders, we are able to increase the aggregate commitments under the Credit Facility by up to an additional $250.0 million . Portions of the Credit Facility up to $50.0 million will be available for the issuance of swing line loans. The Credit Facility bears interest at a base rate or LIBOR, at our option, plus an applicable margin. Depending on our leverage ratio, the applicable margin varies (i) in the case of LIBOR loans, from 2.00% to 3.25% and (ii) in the case of base rate loans, from 1.00% to 2.25% . The base rate is the highest of (i) the prime rate announced by JPMorgan Chase Bank, (ii) the Federal Funds Effective Rate plus 0.50% and (iii) one-month LIBOR plus 1.00% . At December 31, 2018 , the applicable margin on amounts outstanding was 2.7% . The weighted average annual interest rate at December 31, 2018 and 2017 on the outstanding balance under the facility, excluding the effect of interest rate swaps, was 5.4% and 4.8% , respectively. Additionally, we are required to pay commitment fees based on the daily unused amount of the Credit Facility in an amount, depending on our leverage ratio, ranging from 0.375% to 0.50% . We incurred $2.1 million , $2.1 million and $1.4 million in commitment fees on the daily unused amount of our facilities during the years ended December 31, 2018 , 2017 and 2016 , respectively. Our Credit Facility borrowing base consists of eligible accounts receivable, inventory and compressor units. The largest component is eligible compressor units. Borrowings under the Credit Facility are secured by substantially all of our personal property assets and our Significant Domestic Subsidiaries (as defined in our Credit Facility agreement), including all of the membership interests of our Domestic Subsidiaries (as defined in our Credit Facility agreement). Our Credit Facility agreement contains various covenants including, but not limited to, restrictions on the use of proceeds from borrowings and limitations on our ability to incur additional indebtedness, engage in transactions with affiliates, merge or consolidate, sell assets, make certain investments and acquisitions, make loans, grant liens, repurchase equity and pay distributions. Our Credit Facility agreement also contains various covenants requiring mandatory prepayments from the net cash proceeds of certain asset transfers. In addition, if as of any date we have cash and cash equivalents (other than proceeds from a debt or equity issuance received in the 30 days prior to such date reasonably expected to be used to fund an acquisition permitted under the Credit Facility agreement) in excess of $50.0 million , then such excess amount will be used to pay down outstanding borrowings of a corresponding amount under our Credit Facility. We must maintain the following consolidated financial ratios, as defined in our 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. A material adverse effect on our assets, liabilities, financial condition, business or operations that, taken as a whole, impacts our ability to perform its obligations under the Credit Facility agreement, could lead to a default under that agreement. A default under one of our debt agreements would trigger cross-default provisions under our other debt agreements, which would accelerate our obligation to repay our indebtedness under those agreements. As of December 31, 2018 , we were in compliance with all financial covenants under the Credit Facility. As of December 31, 2018 , we had $15.2 million outstanding letters of credit under the Credit Facility and undrawn capacity of $395.3 million . As a result of the ratio requirements above, $391.6 million of the $395.3 million of undrawn capacity was available for additional borrowings as of December 31, 2018 . As of December 31, 2018 , we were in compliance with all covenants under the Credit Facility agreement. During the year ended December 31, 2016, we incurred transaction costs of $1.7 million and expensed $0.4 million of unamortized deferred financing costs related to an amendment to the Former Credit Facility which were reflected in other long-term assets in our consolidated balance sheet and interest expense in our consolidated statement of operations, respectively. 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 our 6% Senior Notes due April 2021) 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. 6% Senior Notes Due April 2021 In March 2013, we issued $350.0 million aggregate principal amount of 6% senior notes due April 2021. These notes were issued at an original issuance discount of $5.5 million , which is being amortized at an effective interest rate of 6.25% over their term. In January 2014, holders of these notes exchanged their notes for registered notes with the same terms. We may redeem all or a part of these notes at redemption prices (expressed as percentages of principal amount) equal to 101.5% for the 12-month period beginning on April 1, 2018 and 100.0% for the 12-month period beginning on April 1, 2019 and at any time thereafter, plus accrued and unpaid interest, if any, to the applicable redemption date. 6% Senior Notes Due October 2022 In April 2014, we issued $350.0 million aggregate principal amount of 6% senior notes due October 2022. These notes were issued at an original issuance discount of $5.7 million , which is being amortized at an effective interest rate of 6.25% over their term. In February 2015, holders of these notes exchanged their notes for registered notes with the same terms. On or after April 1, 2018, we may redeem all or a part of these notes at redemption prices (expressed as percentages of principal amount) equal to 103.0% for the 12-month period beginning on April 1, 2018, 101.5% for the 12-month period beginning on April 1, 2019 and 100.0% for the 12-month period beginning on April 1, 2020 and at any time thereafter, plus accrued and unpaid interest, if any, to the applicable redemption date. Long-Term Debt Maturity Schedule Contractual maturities of long-term debt, excluding interest to be accrued, at December 31, 2018 were as follows (in thousands): 2019 $ — 2020 — 2021 (1) 350,000 2022 (1) 1,189,500 2023 — Total debt (1) $ 1,539,500 —————— (1) Includes the full face value of the Notes and has not been reduced by the aggregate unamortized discount of $4.6 million and the aggregate unamortized deferred financing costs of $5.4 million as of December 31, 2018 .

Partners' Capital

Partners' Capital	12 Months Ended
	Dec. 31, 2018
Equity [Abstract]
Partners' Capital	10. Partners’ Capital Merger Transaction On April 26, 2018, Archrock completed the acquisition of all of our outstanding common units that it did not already own and, as a result, we became its wholly-owned subsidiary. 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 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. 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 our 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 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. Prior to the Merger, we made cash distributions of available cash (as defined in our Partnership Agreement) from operating surplus in the following manner: • first , 98% to all common unitholders, pro rata, and 2% to our general partner, until each unit has received a distribution of $0.4025 ; • second , 85% to all common unitholders, pro rata, and 15% to our general partner, until each unit has received a distribution of $0.4375 ; • third , 75% to all common unitholders, pro rata, and 25% to our general partner, until each unit has received a total of $0.5250 ; and • thereafter , 50% to all common unitholders, pro rata, and 50% to our general partner. On January 29, 2019 , our board of directors declared a quarterly distribution of $0.2400 per common unit that was paid on February 13, 2019 .

Unit-Based Compensation

Unit-Based Compensation	12 Months Ended
	Dec. 31, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Unit-Based Compensation	11. Unit-Based Compensation During the years ended December 31, 2018 , 2017 and 2016 , we recognized $0.3 million , $1.1 million and $1.2 million of unit-based compensation expense, respectively, which excludes unit-based compensation expense that was charged back to Archrock of $0.1 million , $0.5 million and $0.6 million , respectively. 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. During the years ended December 31, 2018, 2017 and 2016, we recorded an immaterial adjustment to SG&A expense related to the fair value remeasurement of phantom units. 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 year ended December 31, 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 10 (“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	12 Months Ended
	Dec. 31, 2018
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivatives	12. 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 December 31, 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 May 2020 100 March 2022 300 $ 500 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 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 $3.2 million of the deferred gain attributable to interest rate swaps included in accumulated other comprehensive income (loss) at December 31, 2018 will be reclassified into earnings as interest income at then-current values during the next 12 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 December 31, 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 consolidated balance sheets (in thousands): Fair Value Asset (Liability) December 31, 2018 December 31, 2017 Derivative asset - current $ 3,185 $ 186 Other long-term assets 4,122 4,490 Derivative liability - current — (134 ) $ 7,307 $ 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): Year Ended December 31, 2018 2017 2016 Pre-tax gain (loss) recognized in other comprehensive income (loss) $ 3,512 $ 5,553 $ (3,069 ) Pre-tax gain (loss) reclassified from accumulated other comprehensive income (loss) into interest expense, net 681 (3,093 ) (4,457 ) Year Ended Total amount of interest expense, net in which the effects of cash flow hedges are recorded $ 90,313 Amount of gain reclassified from accumulated other comprehensive income into interest expense, net 1,283 See Note 1 (“Organization and Summary of Significant Accounting Policies”) and Note 13 (“Fair Value Measurements”) for further details on our derivative instruments.

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2018
Fair Value Disclosures [Abstract]
Fair Value Measurements	13. 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 LIBOR 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): December 31, 2018 2017 Interest rate swaps asset $ 7,307 $ 4,676 Interest rate swaps liability — (134 ) Assets and Liabilities Measured at Fair Value on a Nonrecurring Basis During the years ended December 31, 2018 and 2017 , 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 $1.0 million and $1.8 million at December 31, 2018 and 2017 , respectively. See Note 14 (“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): December 31, 2018 2017 Carrying amount of fixed rate debt (1) $ 690,001 $ 686,747 Fair value of fixed rate debt 674,000 702,000 —————— (1) Carrying amounts are shown net of unamortized debt discounts and unamortized deferred financing costs. See Note 9 (“Long-Term Debt”) .

Long-Lived Asset Impairment

Long-Lived Asset Impairment	12 Months Ended
	Dec. 31, 2018
Asset Impairment Charges [Abstract]
Long-Lived Asset Impairment	14. 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): Year Ended December 31, 2018 2017 2016 Idle compressor units retired from the active fleet 170 230 430 Horsepower of idle compressor units retired from the active fleet 57,000 71,000 155,000 Impairment recorded on idle compressor units retired from the active fleet $ 13,727 $ 17,959 $ 42,460 Additional impairment recorded on available-for-sale compressor units previously culled $ — $ — $ 3,798 In addition to the impairment discussed above, $1.1 million of property, plant and equipment, including 5,000 horsepower of idle compressor units, was impaired during the year ended December 31, 2017 as the result of physical asset observations and other events that indicated the assets’ carrying values were not recoverable.

Restructuring Charges

Restructuring Charges	12 Months Ended
	Dec. 31, 2018
Restructuring and Related Activities [Abstract]
Restructuring Charges	15. Restructuring Charges In the first quarter of 2016, Archrock determined to undertake a cost reduction program to reduce its on-going operating expenses, including workforce reductions and closure of certain make-ready shops. These actions were the result of Archrock’s review of its business and efforts to efficiently manage cost and maintain its business in line with current and expected activity levels and anticipated make-ready demand in the U.S. market. During the year ended December 31, 2016, we incurred $7.3 million , respectively, of restructuring charges comprised of an allocation of expenses related to severance benefits and consulting fees associated with this cost reduction plan from Archrock to us pursuant to the terms of the Omnibus Agreement based on horsepower and other factors. These charges are reflected as restructuring charges in our consolidated statements of operations. Archrock’s cost reduction program under this plan was completed during the fourth quarter of 2016.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Income Taxes	16. Income Taxes Tax Cuts and Jobs Act In December 2017, the TCJA was enacted and significantly reformed the Internal Revenue Code of 1986, as amended. The TCJA included a number of U.S. tax law changes which impact us. For U.S. federal income tax purposes we are treated as a partnership and are not subject to U.S. federal income tax at the entity level. As such, the corporate tax rate change is not applicable to us and no remeasurement of our deferred tax liabilities was necessary. Current and Deferred Tax Provision As a partnership, we are generally not subject to income taxes at the entity level because our income is included in the tax returns of our partners. However, certain states impose an entity-level income tax on partnerships. The provision for state income taxes consisted of the following (in thousands): Year Ended December 31, 2018 2017 2016 Current tax provision: State $ 504 $ (2 ) $ (32 ) Total current 504 (2 ) (32 ) Deferred tax provision: State (29 ) 3,384 1,444 Total deferred (29 ) 3,384 1,444 Provision for income taxes $ 475 $ 3,382 $ 1,412 Deferred income tax balances are the direct effect of temporary differences between the financial statement carrying amounts and the tax basis of assets and liabilities at the enacted tax rates expected to be in effect when the taxes are actually paid or recovered. During the year ended December 31, 2017, we released our entire $2.5 million deferred state tax liability due to the remeasurement of our uncertain tax positions. No new temporary differences arose in the year ended December 31, 2018 that required a deferred income tax balance be recorded due to our uncertain tax position. Unrecognized Tax Benefit A reconciliation of the beginning and ending amount of unrecognized tax benefits is shown below (in thousands): Year Ended December 31, 2018 2017 2016 Beginning balance $ 6,902 $ 1,882 $ 1,962 Additions based on tax positions related to current year 1,544 1,625 121 Additions based on tax positions related to prior years (1) (20 ) 3,395 — Reductions based on lapse of statute of limitations (702 ) — — Reductions based on settlement payments to (refunds from) government authorities (1,084 ) — (201 ) Ending balance $ 6,640 $ 6,902 $ 1,882 —————— (1) Appellate court decisions during the year ended December 31, 2017 required us to remeasure certain of our uncertain tax positions and increase our unrecognized tax benefit for these positions in 2017. We had $6.6 million , $6.9 million and $1.9 million of unrecognized tax benefits at December 31, 2018 , 2017 and 2016 , respectively, of which $3.3 million , $3.6 million and $1.9 million , respectively, would affect the effective tax rate if recognized. We recorded $1.2 million , $1.0 million and $0.1 million of potential interest expense and penalties related to unrecognized tax benefits associated with uncertain tax positions during the years ended December 31, 2018 , 2017 and 2016 , respectively, in our consolidated balance sheets. To the extent interest and penalties are not assessed with respect to uncertain tax positions, amounts accrued will be reduced and reflected as reductions in income tax expense. During the years ended December 31, 2018 , 2017 and 2016 , we recorded $0.2 million , $0.9 million , and $0.1 million , respectively, of potential interest expense and penalties in our consolidated statements of operations. We and our subsidiaries file income tax returns in the U.S. federal jurisdiction and in numerous state jurisdictions. U.S. federal and state income tax returns are generally subject to examination for a period of three to five years after filing the returns. However, the state impact of any U.S. federal audit adjustments and amendments remain subject to examination by various states for up to one year after formal notification to the states. We are currently involved in one state audit. During 2018 and 2016, we settled certain audits which resulted in refunds of $0.6 million and $1.2 million , respectively, and reductions of previously-accrued uncertain tax benefits of $1.1 million and $0.2 million , respectively. As of December 31, 2018 , we believe $1.2 million of our unrecognized tax benefits will be reduced prior to December 31, 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. U.S. Federal Tax Considerations The following table reconciles net loss to our U.S. federal partnership taxable income (loss) (in thousands): Year Ended December 31, 2018 2017 2016 Net income (loss) $ 57,283 $ (421 ) $ (10,757 ) Book/tax depreciation and amortization adjustment (133,735 ) (179,330 ) (289,694 ) Book/tax long-lived asset impairment 13,727 19,107 46,258 Book/tax adjustment for unit-based compensation expense 314 835 978 Book/tax adjustment for interest rate swap terminations 955 2,410 364 Other temporary differences 9,761 (13,781 ) (5,390 ) Other permanent differences 2,708 3,422 1,796 U.S. federal partnership taxable loss $ (48,987 ) $ (167,758 ) $ (256,445 ) The following allocations and adjustments (which are not reflected in the reconciliation because they do not affect our total taxable income) may affect the amount of taxable income or loss allocated to a unitholder: • IRC Section 704(c) Allocations. We make special allocations under IRC Section 704(c) to eliminate the disparity between a unitholder’s U.S. GAAP capital account (credited with the fair market value of contributed property or the investment) and tax capital account (credited with the investor’s tax basis). The effect of such allocations will be to either increase or decrease a unitholder’s share of depreciation, amortization and/or gain or loss on the sale of assets. • IRC Section 743(b) Basis Adjustments. Because we have made the election provided by IRC Section 754, we adjust each unitholder’s basis in our assets (inside basis) pursuant to IRC Section 743(b) to reflect their purchase price (outside basis). The Section 743(b) adjustment belongs to a particular unitholder and not to other unitholders. Basis adjustments such as this give rise to income and deductions by reference to the portion of each transferee unitholder’s purchase price attributable to each of our assets. The effect of such adjustments will be to either increase or decrease a unitholder’s share of depreciation, amortization and/or gain or loss on sale of assets. • Gross Income and Loss Allocations. To maintain the uniformity of the economic and tax characteristics of our units, we will sometimes make a special allocation of income or loss to a unitholder. Any such allocations of income or loss will decrease or increase, respectively, our distributive taxable income. The net tax basis in our assets and liabilities is less than the reported amounts on the financial statements by approximately $700 million as of December 31, 2018 .

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2018
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	17. 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 December 31, 2018 and 2017 , we accrued $3.2 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. During the fourth quarter of 2018, we settled certain sales and use tax audits which resulted in us recording a $10.5 million net benefit in our consolidated statement of operations. This net benefit was reflected as a decrease of $1.8 million , $8.2 million and $0.1 million to cost of sales (excluding depreciation and amortization), SG&A and interest expense, respectively, and an increase to other income, net of $0.4 million . As of December 31, 2018, these settlements are reflected on the consolidated balance sheet as a $14.0 million tax refund receivable offset by $3.1 million and $0.4 million recorded to due to Archrock, net and accrued liabilities, respectively. 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 and results of operations. 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. On November 16, 2018, the Texas Supreme Court issued decisions for the two remaining cases pending review, EXLP Leasing LLC & EES Leasing LLC v. Loving County Appraisal District and EES Leasing LLC & EXLP Leasing LLC v. Ward County Appraisal District. These decisions affirmed the Galveston Central Appraisal District decision and clarified that the Heavy Equipment Statutes apply to the compressors. These decisions have effectively concluded all litigation. 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. As of December 31, 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.

Selected Quarterly Financial Da

Selected Quarterly Financial Data (Unaudited)	12 Months Ended
	Dec. 31, 2018
Quarterly Financial Information Disclosure [Abstract]
Selected Quarterly Financial Data (Unaudited)	18. Selected Quarterly Financial Data (Unaudited) In management’s opinion, the summarized quarterly financial data below (in thousands) contains all appropriate adjustments, all of which are normally recurring adjustments, considered necessary to present fairly our financial position and results of operations for the respective periods. March 31, 2018 June 30, 2018 September 30, 2018 December 31, Revenue $ 147,002 $ 150,866 $ 154,033 $ 160,457 Gross profit (1) 57,206 56,683 57,899 60,418 Long-lived asset impairment 3,066 3,846 3,673 3,142 Merger-related costs 1,376 1,340 2 — Net income (loss) 10,290 10,481 12,613 23,899 March 31, (2) June 30, September 30, December 31, Revenue $ 137,295 $ 138,255 $ 140,191 $ 141,762 Gross profit (1) 41,909 48,880 40,420 49,901 Long-lived asset impairment 6,210 3,081 5,368 4,447 Net income (loss) (4,316 ) 5,275 (4,013 ) 2,633 —————— (1) Defined as revenue less cost of sales, direct depreciation and amortization and long-lived asset impairment charges. (2) In the first quarter of 2017, we recorded $0.3 million of debt extinguishment loss (see Note 9 (“Long-Term Debt”) ).

SCHEDULE II _ VALUATION AND QUA

SCHEDULE II — VALUATION AND QUALIFYING ACCOUNTS	12 Months Ended
	Dec. 31, 2018
SEC Schedule, 12-09, Valuation and Qualifying Accounts [Abstract]
SCHEDULE II — VALUATION AND QUALIFYING ACCOUNTS	SCHEDULE II — VALUATION AND QUALIFYING ACCOUNTS (in thousands) Balance at Beginning of Period Charged to Costs and Expenses Deductions (1) Balance at End of Period Allowance for doubtful accounts deducted from accounts receivable in the balance sheet: December 31, 2018 $ 1,296 $ 1,105 $ 1,148 $ 1,253 December 31, 2017 1,398 4,104 4,206 1,296 December 31, 2016 2,463 2,672 3,737 1,398 —————— (1) Uncollectible accounts written off.

Organization and Summary of S_2

Organization and Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2018
Accounting Policies [Abstract]
Principles of Consideration	The accompanying consolidated financial statements include us and our subsidiaries. All intercompany accounts and transactions have been eliminated in consolidation
Use of Estimates in the Financial Statements	The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amount of assets, liabilities, revenues, expenses and disclosures of contingent assets and liabilities. Because of the inherent uncertainties in this process, actual future results could differ from those expected as of the reporting date. Management believes that the estimates and assumptions used are reasonable.
Revenue Recognition	Revenue Recognition 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 consolidated balance sheet and consolidated statements of operations (in thousands): December 31, 2018 Balance Sheet As Reported Balance Excluding the Impact of the Revenue Recognition Update Effect of Change Assets Accounts receivable, trade $ 80,606 $ 80,291 $ 315 Contract costs 32,220 — 32,220 Liabilities Accrued liabilities $ 10,129 $ 9,833 $ 296 Deferred revenue 9,577 2,002 7,575 Other long-term liabilities 9,175 9,187 (12 ) Equity Common units $ 488,209 $ 464,104 $ 24,105 General partner units 11,630 11,059 571 —————— (1) Represents the impact of the Revenue Recognition Update on net income attributable to noncontrolling interest which was reclassed to additional paid-in capital pursuant to the Merger. December 31, 2018 Statement of Operations As Reported Balance Excluding the Impact of the Revenue Recognition Update Effect of Change Revenue $ 612,358 $ 616,311 $ (3,953 ) Cost of sales (excluding depreciation and amortization) 244,576 258,808 (14,232 ) Selling, general and administrative 70,030 71,701 (1,671 ) Provision for income taxes 475 487 (12 ) Net income (loss) 57,283 45,321 11,962
Concentrations of Credit Risk	Concentrations of Credit Risk Financial instruments that potentially subject us to concentrations of credit risk consist of trade accounts receivable. Trade accounts receivable are due from companies of varying size engaged principally in oil and natural gas activities throughout the U.S. We review the financial condition of customers prior to extending credit and generally do not obtain collateral for trade receivables. Payment terms are on a short-term basis and in accordance with industry practice. We consider this credit risk to be limited due to these companies’ financial resources, the nature of services we provide and the terms of our contract operations customer service agreements.
Property, Plant and Equipment	Property, Plant and Equipment Property, plant and equipment includes compression equipment that is recorded at cost and depreciated using the straight-line method over their estimated useful lives. For compression equipment, depreciation begins with the first compression service. The estimated useful life for compression equipment is 15 to 30 years. Major improvements that extend the useful life of a compressor unit are capitalized and depreciated over the estimated useful life of the major improvement, up to seven years. Repairs and maintenance are expensed as incurred. When property, plant and equipment is sold, retired or otherwise disposed of, the gain or loss is recorded in other (income) loss, net.
Long-Lived Assets	Long-Lived Assets 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. An impairment loss exists when estimated undiscounted cash flows expected from the use of the asset and its eventual disposition are less than its carrying amount. Impairment losses are recognized in the period in which the impairment occurs and represent the excess of the asset carrying value over its fair value. Identifiable intangibles are amortized over the estimated useful life of the asset.
Due To/From Affiliates, Net	Due To/From Affiliates, Net We have receivables and payables with Archrock. A valid right of offset exists related to the receivables and payables with our affiliates and as a result, we present such amounts on a net basis in our consolidated balance sheets. The transactions reflected in due to/from affiliates, net, primarily consist of centralized cash management activities between us and Archrock. Because these balances are treated as short-term borrowings between us and Archrock, serve as a financing and cash management tool to meet our short-term operating needs, are large, turn over quickly and are payable on demand, we present borrowings and repayments with our affiliates on a net basis within the consolidated statements of cash flows. Net receivables from our affiliates are considered advances and changes are presented as investing activities in the consolidated statements of cash flows. Net payables due to our affiliates are considered borrowings and changes are presented as financing activities in the consolidated statements of cash flows.
Income Taxes	Income Taxes As a partnership, all income, gains, losses, expenses, deductions and tax credits we generate generally flow through to our unitholders. However, some states impose an entity-level income tax on partnerships, including us. We account for income taxes under the asset and liability method which requires the recognition of deferred tax assets and liabilities for the expected future tax consequences of events included in the financial statements. Under this method, deferred tax assets and liabilities are determined based on the differences between the financial statements and the tax basis of assets and liabilities using enacted tax rates in effect for the year in which the differences are expected to reverse. The effect of a change in tax rate on deferred tax assets and liabilities is recognized in income in the period that includes the enactment date. We record uncertain tax positions in accordance with the accounting standard on income taxes under a two-step process whereby (1) we determine whether it is more likely than not that the tax positions will be sustained based on the technical merits of the position and (2) for those tax positions that meet the more-likely-than-not recognition threshold, we recognize the largest amount of tax benefit that is greater than 50 percent likely to be realized upon ultimate settlement with the related tax authority.
Hedging and Use of Derivative Instruments	Hedging and Use of Derivative Instruments We use derivative instruments to manage our exposure to fluctuations in the variable interest rate of the Credit Facility and thereby minimize the risks and costs associated with financial activities. We do not use derivative instruments for trading or other speculative purposes. We record interest rate swaps on the balance sheet as either derivative assets or derivative liabilities measured at their fair value. The fair value of our derivatives is based on the income approach (discounted cash flow) using market observable inputs, including LIBOR forward curves. Changes in the fair value of the derivatives designated as cash flow hedges are 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, the same statement of operations line item to which the earnings effect of the hedged item is recorded. To qualify for hedge accounting treatment, we must formally document, designate and assess the effectiveness of the transactions. If the necessary correlation ceases to exist or if the anticipated transaction is no longer probable, we would discontinue hedge accounting and apply mark-to-market accounting. Amounts paid or received from interest rate swap agreements are charged or credited to interest expense and matched with the cash flows and interest expense of the debt being hedged, resulting in an adjustment to the effective interest rate.
Accounting Standards Updates	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. 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. As a result of the adoption of ASU 2016-15 we reclassified $0.3 million of insurance proceeds from net cash provided by operating activities to net cash used in investing activities in our consolidated statement of cash flows during the year ended December 31, 2017 .
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. 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 including an option not to apply the recognition requirements to short term leases. 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. The July 2018 amendment also 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 Leases 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 evaluated the impact of the July 2018 amendment on our contract operations services agreements and have concluded that the services nonlease component is predominant, which results in the ongoing recognition following the Revenue Recognition Update guidance. In conjunction with our assessment of ASC Topic 842 Leases we established a cross-functional implementation team to identify our lease population and to assess changes to our internal control structure, business processes, systems and accounting policies necessary to implement the standard. Based on our review, we have determined that ASC Topic 842 Leases will not have an impact on our consolidated balance sheet or statement of operations because of the available practical expedients.

Recent Accounting Developments

Recent Accounting Developments (Tables)	12 Months Ended
	Dec. 31, 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 consolidated balance sheet and consolidated statements of operations (in thousands): December 31, 2018 Balance Sheet As Reported Balance Excluding the Impact of the Revenue Recognition Update Effect of Change Assets Accounts receivable, trade $ 80,606 $ 80,291 $ 315 Contract costs 32,220 — 32,220 Liabilities Accrued liabilities $ 10,129 $ 9,833 $ 296 Deferred revenue 9,577 2,002 7,575 Other long-term liabilities 9,175 9,187 (12 ) Equity Common units $ 488,209 $ 464,104 $ 24,105 General partner units 11,630 11,059 571 —————— (1) Represents the impact of the Revenue Recognition Update on net income attributable to noncontrolling interest which was reclassed to additional paid-in capital pursuant to the Merger. December 31, 2018 Statement of Operations As Reported Balance Excluding the Impact of the Revenue Recognition Update Effect of Change Revenue $ 612,358 $ 616,311 $ (3,953 ) Cost of sales (excluding depreciation and amortization) 244,576 258,808 (14,232 ) Selling, general and administrative 70,030 71,701 (1,671 ) Provision for income taxes 475 487 (12 ) Net income (loss) 57,283 45,321 11,962

Revenue from Contracts with C_2

Revenue from Contracts with Customers (Tables)	12 Months Ended
	Dec. 31, 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): Year Ended December 31, 2018 0 - 1,000 horsepower per unit $ 220,413 1,001 - 1,500 horsepower per unit 253,919 Over 1,500 horsepower per unit 135,322 Other (1) 2,704 Total revenue (2) $ 612,358 —————— (1) Primarily relates to fees associated with Partnership-owned non-compressor equipment. (2) Includes $5.9 million related to billable maintenance on Partnership-owned units that was recognized at a point in time. All other revenue is recognized over time.
Schedule of Remaining Performance Obligation	This amount will be recognized through 2022 as follows (in thousands): 2019 2020 2021 2022 Total Remaining performance obligations $ 174,962 $ 56,866 $ 12,699 $ 1,503 $ 246,030

Business Acquisitions (Tables)

Business Acquisitions (Tables)	12 Months Ended
	Dec. 31, 2018
Business Combinations [Abstract]
Schedule of pro forma financial information	The following table shows pro forma financial information for the year ended December 31, 2016 (in thousands, except per unit amount): Year ended December 31, 2016 Revenue $ 589,494 Net income 552 Basic and diluted income per common unit —
Summary of purchase price allocation based on estimated fair values of acquired assets and liabilities as of the acquisition date	The following table summarizes the purchase price allocation based on estimated fair values of the acquired assets as of the acquisition date (in thousands): Fair Value Property, plant and equipment $ 14,929 Intangible assets 3,839 Purchase price $ 18,768
Schedule of amounts of finite-lived intangible assets, and their associated average useful lives	The amount of acquired finite-life intangible assets and their average useful lives were determined based on the period over which the assets are expected to contribute directly or indirectly to our future cash flows and consisted of the following (dollars in thousands): Amount Average Useful Life Contract-based intangible assets $ 3,839 2.3 years

Related Party Transactions (Tab

Related Party Transactions (Tables)	12 Months Ended
	Dec. 31, 2018
Related Party Transactions [Abstract]
Schedule of Related Party Transactions	The following table summarizes the like-kind exchange activity between Archrock and us in 2017 and 2016 prior to the enactment of the TCJA (dollars in thousands): Transferred to Archrock Transferred from Archrock Year Ended December 31, Year Ended December 31, 2017 2016 2017 2016 Compressor units 249 462 251 339 Horsepower 156,600 205,000 145,000 154,000 Net book value $ 78,856 $ 92,382 $ 74,874 $ 96,216 The following table summarizes the aggregate cost and accumulated depreciation of equipment on lease to and from Archrock (in thousands): December 31, 2018 2017 Equipment on lease to Archrock Aggregate cost $ 3,824 $ 3,560 Accumulated depreciation 164 272 Equipment on lease from Archrock Aggregate cost $ 5,040 $ 224 Accumulated depreciation 2,659 34 The following table summarizes the aggregate cost and accumulated depreciation of equipment on lease to and from Archrock (in thousands): December 31, 2018 2017 Equipment on lease to Archrock Aggregate cost $ 3,824 $ 3,560 Accumulated depreciation 164 272 Equipment on lease from Archrock Aggregate cost $ 5,040 $ 224 Accumulated depreciation 2,659 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): Year Ended December 31, 2018 2017 2016 Revenue $ 1,440 $ 708 $ 123 Cost of sales 2,797 1,008 270 Sales The following table summarizes compressor unit sales activity between Archrock and us (dollars in thousands): Year Ended December 31, 2018 Sold to Archrock Purchased from Archrock Compressor units 85 184 Horsepower 53,624 107,431 Net book value $ 38,441 $ 39,937

Intangible Assets, net (Tables)

Intangible Assets, net (Tables)	12 Months Ended
	Dec. 31, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Finite-Lived Intangible Assets	Intangible assets, net consisted of the following (in thousands): December 31, 2018 December 31, 2017 Gross Carrying Amount Accumulated Amortization Gross Carrying Amount Accumulated Amortization Customer related (9-25 year life) $ 56,707 $ (25,908 ) $ 56,707 $ (22,713 ) Contract based (5-7 year life) 64,556 (49,516 ) 68,395 (41,642 ) Intangible assets $ 121,263 $ (75,424 ) $ 125,102 $ (64,355 )
Schedule of Finite-Lived Intangible Assets, Future Amortization Expense	Estimated future intangible amortization expense is as follows (in thousands): 2019 $ 11,623 2020 8,286 2021 3,541 2022 2,472 2023 2,334 Thereafter 17,583 Total $ 45,839

Accrued Liabilities (Tables)

Accrued Liabilities (Tables)	12 Months Ended
	Dec. 31, 2018
Payables and Accruals [Abstract]
Schedule of Accrued Liabilities	Accrued liabilities consisted of the following (in thousands): December 31, 2018 2017 Accrued income and other taxes (1) $ 6,187 $ 5,675 Accrued other liabilities 3,942 1,922 Accrued liabilities $ 10,129 $ 7,597 —————— (1) Represents accruals for taxes including ad valorem tax, sales tax and use tax.

Long-Term Debt (Tables)

Long-Term Debt (Tables)	12 Months Ended
	Dec. 31, 2018
Debt Disclosure [Abstract]
Schedule of long-term debt	Long-term debt consisted of the following (in thousands): December 31, 2018 2017 Credit Facility $ 839,500 $ 674,306 6% senior notes due April 2021 350,000 350,000 Less: Debt discount, net of amortization (1,789 ) (2,523 ) Less: Deferred financing costs, net of amortization (2,311 ) (3,338 ) 345,900 344,139 6% senior notes due October 2022 350,000 350,000 Less: Debt discount, net of amortization (2,766 ) (3,441 ) Less: Deferred financing costs, net of amortization (3,133 ) (3,951 ) 344,101 342,608 Long-term debt $ 1,529,501 $ 1,361,053 We must maintain the following consolidated financial ratios, as defined in our 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.
Schedule of Maturities of Long-term Debt	Contractual maturities of long-term debt, excluding interest to be accrued, at December 31, 2018 were as follows (in thousands): 2019 $ — 2020 — 2021 (1) 350,000 2022 (1) 1,189,500 2023 — Total debt (1) $ 1,539,500 —————— (1) Includes the full face value of the Notes and has not been reduced by the aggregate unamortized discount of $4.6 million and the aggregate unamortized deferred financing costs of $5.4 million as of December 31, 2018 .

Derivatives (Tables)

Derivatives (Tables)	12 Months Ended
	Dec. 31, 2018
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule of derivative instruments	At December 31, 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 May 2020 100 March 2022 300 $ 500
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 consolidated balance sheets (in thousands): Fair Value Asset (Liability) December 31, 2018 December 31, 2017 Derivative asset - current $ 3,185 $ 186 Other long-term assets 4,122 4,490 Derivative liability - current — (134 ) $ 7,307 $ 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): Year Ended December 31, 2018 2017 2016 Pre-tax gain (loss) recognized in other comprehensive income (loss) $ 3,512 $ 5,553 $ (3,069 ) Pre-tax gain (loss) reclassified from accumulated other comprehensive income (loss) into interest expense, net 681 (3,093 ) (4,457 ) Year Ended Total amount of interest expense, net in which the effects of cash flow hedges are recorded $ 90,313 Amount of gain reclassified from accumulated other comprehensive income into interest expense, net 1,283 See Note 1 (“Organization and Summary of Significant Accounting Policies”) and Note 13 (“Fair Value Measurements”) for further details on our derivative instruments.

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 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): December 31, 2018 2017 Interest rate swaps asset $ 7,307 $ 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): December 31, 2018 2017 Carrying amount of fixed rate debt (1) $ 690,001 $ 686,747 Fair value of fixed rate debt 674,000 702,000 —————— (1) Carrying amounts are shown net of unamortized debt discounts and unamortized deferred financing costs. See Note 9 (“Long-Term Debt”) .

Long-Lived Asset Impairment (Ta

Long-Lived Asset Impairment (Tables)	12 Months Ended
	Dec. 31, 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): Year Ended December 31, 2018 2017 2016 Idle compressor units retired from the active fleet 170 230 430 Horsepower of idle compressor units retired from the active fleet 57,000 71,000 155,000 Impairment recorded on idle compressor units retired from the active fleet $ 13,727 $ 17,959 $ 42,460 Additional impairment recorded on available-for-sale compressor units previously culled $ — $ — $ 3,798

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Schedule of Components of Income Tax Expense (Benefit)	The provision for state income taxes consisted of the following (in thousands): Year Ended December 31, 2018 2017 2016 Current tax provision: State $ 504 $ (2 ) $ (32 ) Total current 504 (2 ) (32 ) Deferred tax provision: State (29 ) 3,384 1,444 Total deferred (29 ) 3,384 1,444 Provision for income taxes $ 475 $ 3,382 $ 1,412
Schedule of Unrecognized Tax Benefits Roll Forward	A reconciliation of the beginning and ending amount of unrecognized tax benefits is shown below (in thousands): Year Ended December 31, 2018 2017 2016 Beginning balance $ 6,902 $ 1,882 $ 1,962 Additions based on tax positions related to current year 1,544 1,625 121 Additions based on tax positions related to prior years (1) (20 ) 3,395 — Reductions based on lapse of statute of limitations (702 ) — — Reductions based on settlement payments to (refunds from) government authorities (1,084 ) — (201 ) Ending balance $ 6,640 $ 6,902 $ 1,882 —————— (1) Appellate court decisions during the year ended December 31, 2017 required us to remeasure certain of our uncertain tax positions and increase our unrecognized tax benefit for these positions in 2017.
Schedule Of Reconciliation Of Net Income Loss To US Federal Partnership Taxable Income Loss	The following table reconciles net loss to our U.S. federal partnership taxable income (loss) (in thousands): Year Ended December 31, 2018 2017 2016 Net income (loss) $ 57,283 $ (421 ) $ (10,757 ) Book/tax depreciation and amortization adjustment (133,735 ) (179,330 ) (289,694 ) Book/tax long-lived asset impairment 13,727 19,107 46,258 Book/tax adjustment for unit-based compensation expense 314 835 978 Book/tax adjustment for interest rate swap terminations 955 2,410 364 Other temporary differences 9,761 (13,781 ) (5,390 ) Other permanent differences 2,708 3,422 1,796 U.S. federal partnership taxable loss $ (48,987 ) $ (167,758 ) $ (256,445 )

Selected Quarterly Financial _2

Selected Quarterly Financial Data (Unaudited) (Tables)	12 Months Ended
	Dec. 31, 2018
Quarterly Financial Information Disclosure [Abstract]
Schedule of Quarterly Financial Information	March 31, 2018 June 30, 2018 September 30, 2018 December 31, Revenue $ 147,002 $ 150,866 $ 154,033 $ 160,457 Gross profit (1) 57,206 56,683 57,899 60,418 Long-lived asset impairment 3,066 3,846 3,673 3,142 Merger-related costs 1,376 1,340 2 — Net income (loss) 10,290 10,481 12,613 23,899 March 31, (2) June 30, September 30, December 31, Revenue $ 137,295 $ 138,255 $ 140,191 $ 141,762 Gross profit (1) 41,909 48,880 40,420 49,901 Long-lived asset impairment 6,210 3,081 5,368 4,447 Net income (loss) (4,316 ) 5,275 (4,013 ) 2,633 —————— (1) Defined as revenue less cost of sales, direct depreciation and amortization and long-lived asset impairment charges. (2) In the first quarter of 2017, we recorded $0.3 million of debt extinguishment loss (see Note 9 (“Long-Term Debt”) ).

Organization and Summary of S_3

Organization and Summary of Significant Accounting Policies - Nature of Operations (Details)	12 Months Ended
	Dec. 31, 2018segment
Accounting Policies [Abstract]
Number of reporting segments	1

Organization and Summary of S_4

Organization and Summary of Significant Accounting Policies - Concentration Risk (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Concentration Risk
Provision for doubtful accounts	$ 1,105	$ 4,104	$ 2,672
Customer Concentration Risk | Sales revenue | Williams Partners L.P
Concentration Risk
Concentration risk percentage	14.00%	16.00%	17.00%
Customer Concentration Risk | Sales revenue | Anadarko
Concentration Risk
Concentration risk percentage	9.00%	10.00%	10.00%
Customer Concentration Risk | Accounts receivables | Williams Partners L.P
Concentration Risk
Concentration risk percentage	16.00%	22.00%
Customer Concentration Risk | Accounts receivables | Anadarko
Concentration Risk
Concentration risk percentage	20.00%	13.00%

Organization and Summary of S_5

Organization and Summary of Significant Accounting Policies - Property Plant and Equipment (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Property, Plant and Equipment [Line Items]
Depreciation	$ 121.9	$ 127.9	$ 138
Compression equipment | Minimum
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life	15 years
Compression equipment | Maximum
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life	30 years
Capitalized overhauls and major equipment | Maximum
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life	7 years

Recent Accounting Development_2

Recent Accounting Developments - Narratives (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Jan. 01, 2018
Error Corrections and Prior Period Adjustments Restatement
Proceeds from insurance	$ 252	$ 252	$ 0
ASU 2017-12
Error Corrections and Prior Period Adjustments Restatement
Cumulative-effect adjustment		383
ASU 2015-16
Error Corrections and Prior Period Adjustments Restatement
Proceeds from insurance		300
ASU 2014-09
Error Corrections and Prior Period Adjustments Restatement
Cumulative-effect adjustment		$ 12,714
Retained Earnings | ASU 2017-12
Error Corrections and Prior Period Adjustments Restatement
Cumulative-effect adjustment				$ 400

Recent Accounting Development_3

Recent Accounting Developments - Balance Statement Impact (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Jan. 01, 2018	Dec. 31, 2017
Assets
Contract costs	$ 32,220	$ 16,316	$ 0
Accounts receivable, trade	80,606		67,714
Liabilities
Accrued liabilities	10,129	7,783	7,597
Deferred revenue	9,577	4,715	1,299
Other long-term liabilities	9,175		9,356
Partners’ capital
Common units	488,209	513,485	501,023
General partner units	11,630	11,834	11,582
Balance Excluding the Impact of the Revenue Recognition Update
Assets
Contract costs	0		0
Accounts receivable, trade	80,291
Liabilities
Accrued liabilities	9,833		7,597
Deferred revenue	2,002		1,299
Other long-term liabilities	9,187
Partners’ capital
Common units	464,104		501,023
General partner units	11,059		$ 11,582
Adjustments Due to the Revenue Recognition Update | ASU 2014-09
Assets
Contract costs	32,220	16,316
Accounts receivable, trade	315
Liabilities
Accrued liabilities	296	186
Deferred revenue	7,575	3,416
Other long-term liabilities	(12)
Partners’ capital
Common units	24,105	12,462
General partner units	$ 571	$ 252

Recent Accounting Development_4

Recent Accounting Developments - Income Statement Impact (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Revenue, Initial Application Period Cumulative Effect Transition
Revenue	$ 160,457	$ 154,033	$ 150,866	$ 147,002	$ 141,762	$ 140,191	$ 138,255	$ 137,295	$ 612,358	$ 557,503	$ 562,360
Cost of sales (excluding depreciation and amortization)									244,576	229,355	209,411
Selling, general and administrative									70,030	82,035	79,717
Provision for income taxes									475	3,382	1,412
Net income (loss)	$ 23,899	$ 12,613	$ 10,481	$ 10,290	$ 2,633	$ (4,013)	$ 5,275	$ (4,316)	57,283	$ (421)	$ (10,757)
Balance Excluding the Impact of the Revenue Recognition Update
Revenue, Initial Application Period Cumulative Effect Transition
Revenue									616,311
Cost of sales (excluding depreciation and amortization)									258,808
Selling, general and administrative									71,701
Provision for income taxes									487
Net income (loss)									45,321
ASU 2014-09 | Adjustments Due to the Revenue Recognition Update
Revenue, Initial Application Period Cumulative Effect Transition
Revenue									(3,953)
Cost of sales (excluding depreciation and amortization)									(14,232)
Selling, general and administrative									(1,671)
Provision for income taxes									(12)
Net income (loss)									$ 11,962

Revenue from Contracts with C_3

Revenue from Contracts with Customers - Disaggregate Revenue (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Disaggregation of Revenue
Revenue	$ 160,457	$ 154,033	$ 150,866	$ 147,002	$ 141,762	$ 140,191	$ 138,255	$ 137,295	$ 612,358	$ 557,503	$ 562,360
0 - 1,000 horsepower per unit
Disaggregation of Revenue
Revenue									220,413
1,001 - 1,500 horsepower per unit
Disaggregation of Revenue
Revenue									253,919
Over 1,500 horsepower per unit
Disaggregation of Revenue
Revenue									135,322
Other
Disaggregation of Revenue
Revenue									2,704
Other | Transferred at Point in Time
Disaggregation of Revenue
Revenue									$ 5,900

Revenue from Contracts with C_4

Revenue from Contracts with Customers - Remaining Performance Obligation (Details) $ in Thousands	Dec. 31, 2018USD ($)
Revenue from Contract with Customer [Abstract]
Remaining performance obligations	$ 246,030
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-01-01
Revenue from Contract with Customer [Abstract]
Remaining performance obligations	$ 174,962
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction
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	$ 56,866
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction
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	$ 12,699
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction
Performance obligations expected to be satisfied, expected timing	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-01-01
Revenue from Contract with Customer [Abstract]
Remaining performance obligations	$ 1,503
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction
Performance obligations expected to be satisfied, expected timing	1 year

Revenue from Contracts with C_5

Revenue from Contracts with Customers - Contract Balances (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Jan. 01, 2018	Dec. 31, 2017
Disaggregation of Revenue
Accounts receivable, trade	$ 80,606		$ 67,714
Contract liability with customer	9,700	$ 5,400
Increase in contract liability from freight billing	18,000
Revenue from contract liability	13,700
Trade accounts receivable
Disaggregation of Revenue
Accounts receivable, trade	$ 78,600	$ 66,200

Business Acquisitions - Novembe

Business Acquisitions - November 2016 Contract Operations Acquisitions - Narratives (Details) hp in Thousands, $ in Thousands	1 Months Ended		3 Months Ended				12 Months Ended
	Aug. 31, 2017shares	Nov. 30, 2016USD ($)customercompressor_unithpshares	Dec. 31, 2018USD ($)	Sep. 30, 2018USD ($)	Jun. 30, 2018USD ($)	Mar. 31, 2018USD ($)	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)shares
Business Acquisitions
Accumulated depreciation of leased equipment			$ 1,042,182				$ 1,042,182	$ 953,325
Merger-related costs			$ 0	$ 2	$ 1,340	$ 1,376	$ 2,718	$ 1	$ 0
Partners' Capital General Partner Units
Business Acquisitions
Units issued in connection with acquisition (in units) | shares	93,163
Archrock
Business Acquisitions
Number of customers with service agreements | customer		63
Number of compressor units used to provide compression services | compressor_unit		262
Horsepower of compressor units used to provide compression services | hp		147
Business combination, percentage of available horsepower provided		4.00%
Business combination, net book value of assets acquired		$ 66,600
Accumulated depreciation of leased equipment		55,600
Business combination, consideration transferred		85,000
Merger-related costs									400
Finite lived assets acquired		$ 1,100
Distributions recorded related to differences in net book value of compressor units exchanged to our assets transferred to related party									$ 17,300
Archrock | Partners' Capital Common Units
Business Acquisitions
Units issued in connection with acquisition (in units) | shares		5,500,000
Archrock | Partners' Capital General Partner Units
Business Acquisitions
Units issued in connection with acquisition (in units) | shares		111,040							111,040

Business Acquisitions - Unaudit

Business Acquisitions - Unaudited Pro Forma Financial Information - Narratives (Details) - shares	1 Months Ended		12 Months Ended
	Aug. 31, 2017	Nov. 30, 2016	Dec. 31, 2016
Partners' Capital General Partner Units
Business Acquisitions
Units issued in connection with acquisition (in units)	93,163
Archrock | Partners' Capital Common Units
Business Acquisitions
Units issued in connection with acquisition (in units)		5,500,000
Archrock | Partners' Capital General Partner Units
Business Acquisitions
Units issued in connection with acquisition (in units)		111,040	111,040

Business Acquisitions - Unaud_2

Business Acquisitions - Unaudited Pro Forma Financial Information (Details) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2016USD ($)$ / shares
Pro forma financial information
Revenue	$ 589,494
Net income	$ 552
Basic and diluted income per common unit (usd per unit) | $ / shares	$ 0

Business Acquisitions - March 2

Business Acquisitions - March 2016 Acquisition - Narratives (Details) hp in Thousands, $ in Thousands	Mar. 01, 2016	Aug. 31, 2017shares	Mar. 31, 2016USD ($)customercompressor_unithpshares	Dec. 31, 2018USD ($)	Sep. 30, 2018USD ($)	Jun. 30, 2018USD ($)	Mar. 31, 2018USD ($)	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)shares
Business Acquisitions
Merger-related costs				$ 0	$ 2	$ 1,340	$ 1,376	$ 2,718	$ 1	$ 0
Partners' Capital General Partner Units
Business Acquisitions
Units issued in connection with acquisition (in units) | shares		93,163
General partner units, interest (as a percent)										2.00%
March 2016 Acquisition
Business Acquisitions
Number of customers with service agreements | customer			4
Number of compressor units used to provide compression services | compressor_unit			19
Horsepower of compressor units used to provide compression services | hp			23
Business combination, consideration transferred			$ 18,800
Line of credit outstanding			$ 13,800
Number of like kind exchanged compressor units | compressor_unit			24
Like kind exchanged compressor units, value			$ 3,200
Units issued in connection with acquisition										$ 1,836
Merger-related costs										$ 200
Property, plant and equipment, useful life	15 years
March 2016 Acquisition | Partners' Capital Common Units
Business Acquisitions
Units issued in connection with acquisition (in units) | shares			257,000
Units issued in connection with acquisition			$ 1,800
March 2016 Acquisition | Partners' Capital General Partner Units
Business Acquisitions
Units issued in connection with acquisition (in units) | shares			5,205							5,205
Units issued in connection with acquisition										$ 37
General partner units, interest (as a percent)			2.00%

Business Acquisitions - Net Ass

Business Acquisitions - Net Assets Acquired (Details) - March 2016 Acquisition $ in Thousands	Mar. 31, 2016USD ($)
Net Assets Acquired
Property, plant and equipment	$ 14,929
Intangible assets	3,839
Purchase price	$ 18,768

Business Acquisitions - Finite

Business Acquisitions - Finite Lived Assets Acquired (Details) - March 2016 Acquisition - Contract-based intangible assets $ in Thousands	1 Months Ended
	Mar. 31, 2016USD ($)
Business Acquisitions
Total acquired identifiable intangible assets	$ 3,839
Weighted average useful life	2 years 3 months 18 days

Related Party Transactions - Na

Related Party Transactions - Narratives (Details)	Apr. 26, 2018USD ($)	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)contract	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)
Related party transactions
Repayments of long-term debt		$ 438,636,000	$ 904,194,000	$ 328,500,000
Indemnification period following each applicable asset acquisition from related party		3 years
Maximum liability of related party for environmental indemnification liability		$ 5,000,000
Aggregate losses which must be exceeded for applicability of environmental or any other indemnification obligation		250,000,000
Indemnification liability		0	0	0
Distribution of capital - excess of fair market value of equipment purchased from Archrock over equipment sold to Archrock		13,951,000
Archrock | Affiliated Entity
Related party transactions
Loan receivable due from Archrock		20,000,000
Interest income		1,800,000
Amount contributed by related party related to completion of overhauls on compression equipment		2,900,000	$ 5,200,000	1,200,000
Contributions (distributions) recorded related to differences in net book value of compressor units exchanged to our assets transferred to related party		(1,500,000)		4,000,000	$ (3,800,000)
Distribution of capital - excess of fair market value of equipment purchased from Archrock over equipment sold to Archrock		14,000,000
Number of customer contracts included in transfers | contract			0
Cost of sales (excluding depreciation and amortization) — affiliates		14,100,000	$ 17,300,000	4,800,000
Selling, general and administrative — affiliates		$ 66,600,000	$ 68,700,000	$ 68,800,000
Credit Facility | Credit Facility | Archrock | Affiliated Entity
Related party transactions
Repayments of long-term debt	$ 63,200,000

Related Party Transactions - Ag

Related Party Transactions - Aggregate Cost and Accumulated Depreciation (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Related party transactions
Accumulated depreciation	$ 1,042,182	$ 953,325
Archrock | Affiliated Entity | Equipment on lease to Archrock
Related party transactions
Aggregate cost	3,824		$ 3,560
Accumulated depreciation	164		272
Archrock | Affiliated Entity | Equipment on lease from Archrock
Related party transactions
Aggregate cost	5,040		224
Accumulated depreciation	$ 2,659		$ 34

Related Party Transactions - Re

Related Party Transactions - Revenue From Related Party (Details) - Archrock - Affiliated Entity - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2016	Dec. 31, 2015
Related party transactions
Revenue	$ 1,440	$ 708	$ 123
Cost of sales	$ 2,797	$ 1,008	$ 270

Related Party Transactions - Sa

Related Party Transactions - Sales and Transfers of Compressor Units (Details) - Archrock - Affiliated Entity $ in Thousands	12 Months Ended
	Dec. 31, 2018USD ($)compressor_unithp	Dec. 31, 2017USD ($)compressor_unithp	Dec. 31, 2016USD ($)compressor_unithp
Related party transactions
Number of compressor units sold to related party | compressor_unit	85
Horsepower of compressor units sold to related party | hp	53,624
Net book value of compressor units sold to related party | $	$ 38,441
Number of compressor units purchased from related party | compressor_unit	184
Horsepower of compressor units purchased from related party | hp	107,431
Net book value of compressor units purchased from related party | $	$ 39,937
Number of compressor units transferred to a related party | compressor_unit		249	462
Horsepower of compressor units transferred to related party | hp		156,600	205,000
Net book value of compressor units transferred to related party | $		$ 78,856	$ 92,382
Number of compressor units transferred by related party | compressor_unit		251	339
Horsepower of compressor units transferred by related party | hp		145,000	154,000
Net book value of compressor units transferred by related party | $		$ 74,874	$ 96,216

Contract Costs (Details)

Contract Costs (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Jan. 01, 2018
Disaggregation of Revenue
Contract costs	$ 32,220,000	$ 0		$ 16,316,000
Capitalized contract, term	36 months
Amortization of contract costs	$ 11,709,000	$ 0	$ 0
Impairment loss on customer contracts	0
Sales commissions
Disaggregation of Revenue
Contract costs	3,600,000			2,000,000
Amortization of contract costs	1,300,000
Freight and mobilization
Disaggregation of Revenue
Contract costs	28,600,000			$ 14,300,000
Amortization of contract costs	$ 10,400,000

Intangible Assets, net (Details

Intangible Assets, net (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 121,263	$ 125,102
Accumulated Amortization	(75,424)	(64,355)
Customer related (9-25 year life)
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	56,707	56,707
Accumulated Amortization	$ (25,908)	(22,713)
Customer related (9-25 year life) | Minimum
Finite-Lived Intangible Assets [Line Items]
Useful life	9 years
Customer related (9-25 year life) | Maximum
Finite-Lived Intangible Assets [Line Items]
Useful life	25 years
Contract based (5-7 year life)
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 64,556	68,395
Accumulated Amortization	$ (49,516)	$ (41,642)
Contract based (5-7 year life) | Minimum
Finite-Lived Intangible Assets [Line Items]
Useful life	5 years
Contract based (5-7 year life) | Maximum
Finite-Lived Intangible Assets [Line Items]
Useful life	7 years

Intangible Assets, net - Deprec

Intangible Assets, net - Depreciation (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Goodwill and Intangible Assets Disclosure [Abstract]
Amortization of intangible assets	$ 14.9	$ 15.9	$ 15.8

Intangible Assets, net - Estima

Intangible Assets, net - Estimated Future Amortization Expense (Details) $ in Thousands	Dec. 31, 2018USD ($)
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity
2,019	$ 11,623
2,020	8,286
2,021	3,541
2,022	2,472
2,023	2,334
Thereafter	17,583
Total	$ 45,839

Accrued Liabilities (Details)

Accrued Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Jan. 01, 2018	Dec. 31, 2017
Payables and Accruals [Abstract]
Accrued income and other taxes	$ 6,187		$ 5,675
Accrued other liabilities	3,942		1,922
Accrued liabilities	$ 10,129	$ 7,783	$ 7,597

Long-Term Debt - Schedule of Lo

Long-Term Debt - Schedule of Long-term Debt (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017	Mar. 30, 2017	Apr. 30, 2014	Mar. 31, 2013
Long-Term Debt
Total debt	$ 1,529,501	$ 1,361,053
Senior Notes
Long-Term Debt
Less: Debt discount, net of amortization	(4,600)
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	(1,789)	(2,523)			$ (5,500)
Less: Deferred financing costs, net of amortization	(2,311)	(3,338)
Total debt	$ 345,900	344,139
Interest rate (as a percent)	6.00%				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	(2,766)	(3,441)		$ (5,700)
Less: Deferred financing costs, net of amortization	(3,133)	(3,951)
Total debt	$ 344,101	342,608
Interest rate (as a percent)	6.00%			6.00%
Credit Facility | Credit Facility
Long-Term Debt
Total debt	$ 839,500	$ 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. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Mar. 31, 2018
Long-Term Debt
Repayments of long-term debt				$ 438,636,000	$ 904,194,000	$ 328,500,000
Loss on extinguishment of debt			$ 300,000	$ 0	$ 291,000	0
Credit Facility
Long-Term Debt
Debt issuance cost	$ 3,300,000
Spread on variable rate				2.70%
Weighted average interest rate				5.40%	4.80%
Credit Facility | Minimum
Long-Term Debt
Commitment fees (percentage)				0.375%
Credit Facility | Maximum
Long-Term Debt
Commitment fees (percentage)				0.50%
Credit Facility | Revolving Credit Facility Due March 2022
Long-Term Debt
Interest rate (as a percent)		6.00%
Debt issuance cost		$ 14,900,000
Maximum borrowing capacity	1,250,000,000						$ 1,100,000,000
Change in maximum borrowing amount				$ 250,000,000
Commitment fees				2,100,000
Cash equivalent threshold				50,000,000
Line of credit outstanding				15,200,000
Line of credit remaining borrowing capacity				395,300,000
Credit Facility | Revolving Credit Facility Due March 2022 | Maximum
Long-Term Debt
Line of credit remaining borrowing capacity				391,600,000
Credit Facility | Revolving Credit Facility Due March 2022 | Swing Line
Long-Term Debt
Change in maximum borrowing amount				$ 50,000,000
Credit Facility | Revolving Credit Facility Due March 2022 | Line of Credit | LIBOR | Minimum
Long-Term Debt
Spread on variable rate				2.00%
Credit Facility | Revolving Credit Facility Due March 2022 | Line of Credit | LIBOR | Maximum
Long-Term Debt
Spread on variable rate				3.25%
Credit Facility | Revolving Credit Facility Due March 2022 | Line of Credit | Base Rate | Minimum
Long-Term Debt
Spread on variable rate				1.00%
Credit Facility | Revolving Credit Facility Due March 2022 | Line of Credit | Base Rate | Maximum
Long-Term Debt
Spread on variable rate				2.25%
Credit Facility | Revolving Credit Facility Due March 2022 | Line of Credit | Federal Funds Rate
Long-Term Debt
Interest margin on variable rate				0.50%
Credit Facility | Revolving Credit Facility Due March 2022 | Line of Credit | One-month LIBOR
Long-Term Debt
Interest margin on variable rate				1.00%
Credit Facility | Term loan facility due May 2018
Long-Term Debt
Loss on extinguishment of debt		300,000
Credit Facility | Former Credit Facility
Long-Term Debt
Repayments of long-term debt		648,400,000
Debt issuance cost written off		$ 600,000
Commitment fees					$ 2,100,000	1,400,000
Line of Credit
Long-Term Debt
Debt issuance cost						1,700,000
Debt issuance cost written off						$ 0.4
Letter of credit | Revolving Credit Facility Due March 2022
Long-Term Debt
Maximum borrowing capacity	$ 50,000,000						$ 25,000,000

Long-Term Debt - Debt Ratios (D

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

Long-Term Debt Long-Term Debt -

Long-Term Debt Long-Term Debt - Notes (Details)	Dec. 31, 2018
Archrock Subsidiaries
Long-Term Debt
Ownership percentage (as a percent)	100.00%

Long-Term Debt - 6% Senior Note

Long-Term Debt - 6% Senior Notes Due April 2021 (Details) - Senior Notes - USD ($)	1 Months Ended
	Mar. 31, 2013	Dec. 31, 2018	Dec. 31, 2017
Long-Term Debt
Unamortized discount		$ 4,600,000
6% senior notes due April 2021
Long-Term Debt
Interest rate (as a percent)	6.00%	6.00%
Principal amount	$ 350,000,000
Unamortized discount	$ 5,500,000	$ 1,789,000	$ 2,523,000
Effective interest rate	6.25%
6% senior notes due April 2021 | Debt Instrument, Redemption, Period One
Long-Term Debt
Redemption price, percentage	101.50%
6% senior notes due April 2021 | Debt Instrument, Redemption, Period Two
Long-Term Debt
Redemption price, percentage	100.00%

Long-Term Debt - 6% Senior No_2

Long-Term Debt - 6% Senior Notes Due October 2022 (Details) - Senior Notes - USD ($)	1 Months Ended
	Apr. 30, 2014	Dec. 31, 2018	Dec. 31, 2017
Long-Term Debt
Unamortized discount		$ 4,600,000
6% senior notes due October 2022
Long-Term Debt
Interest rate (as a percent)	6.00%	6.00%
Principal amount	$ 350,000,000
Unamortized discount	$ 5,700,000	$ 2,766,000	$ 3,441,000
Effective interest rate	6.25%
6% senior notes due October 2022 | Debt Instrument, Redemption, Period One
Long-Term Debt
Redemption price, percentage	103.00%
6% senior notes due October 2022 | Debt Instrument, Redemption, Period Two
Long-Term Debt
Redemption price, percentage	101.50%
6% senior notes due October 2022 | Debt Instrument, Redemption, Period Three
Long-Term Debt
Redemption price, percentage	100.00%

Long-Term Debt - Debt Maturity

Long-Term Debt - Debt Maturity Schedule (Details) $ in Thousands	Dec. 31, 2018USD ($)
Long-term Debt, Fiscal Year Maturity
2,019	$ 0
2,020	0
2,021	350,000
2,022	1,189,500
Total debt	1,539,500
Senior Notes
Long-term Debt, Fiscal Year Maturity
Unamortized debt issuance cost	4,600
Deferred financing costs	$ 5,400

Partners' Capital - Narratives

Partners' Capital - Narratives (Details) $ / shares in Units, $ in Thousands	Jan. 29, 2019$ / shares	Apr. 26, 2018shares	Apr. 25, 2018shares	Aug. 31, 2017shares	Aug. 31, 2017USD ($)shares	Dec. 31, 2018USD ($)$ / sharesshares	Dec. 31, 2017USD ($)$ / sharesshares	Dec. 31, 2016USD ($)$ / shares
Partners' Equity, Allocations and Cash Distributions
Ownership percentage held by reporting entity			57.00%
General partner units, equivalent units outstanding (in units)						1,422,458	1,421,768
Common units issued in March 2016 Acquisition | $						$ 0	$ 0	$ 1,799
Distributions (usd per unit) | $ / shares						$ 0.9924	$ 1.14000	$ 1.4275
Subsequent Event
Partners' Equity, Allocations and Cash Distributions
Authorized distributions to limited partnership (usd per unit) | $ / shares	$ 0.2400
Partners' Capital Common Units
Partners' Equity, Allocations and Cash Distributions
Stock issued during the period (shares)				4,600,000
Common units issued in March 2016 Acquisition | $					$ 60,300
Partners' Capital Common Units | Options
Partners' Equity, Allocations and Cash Distributions
Stock issued during the period (shares)				600,000
Partners' Capital Common Units | First
Partners' Equity, Allocations and Cash Distributions
PErcentage of operating surplus (percent)						98.00%
Distributions (usd per unit) | $ / shares						$ 0.4025
Partners' Capital Common Units | Second
Partners' Equity, Allocations and Cash Distributions
PErcentage of operating surplus (percent)						85.00%
Distributions (usd per unit) | $ / shares						$ 0.4375
Partners' Capital Common Units | Third
Partners' Equity, Allocations and Cash Distributions
PErcentage of operating surplus (percent)						75.00%
Distributions (usd per unit) | $ / shares						$ 0.5250
Partners' Capital Common Units | Thereafter
Partners' Equity, Allocations and Cash Distributions
PErcentage of operating surplus (percent)						50.00%
Partners' Capital General Partner Units
Partners' Equity, Allocations and Cash Distributions
Units issued in connection with acquisition (in units)					93,163
General partner units, interest (as a percent)								2.00%
Partners' Capital General Partner Units | First
Partners' Equity, Allocations and Cash Distributions
PErcentage of operating surplus (percent)						2.00%
Partners' Capital General Partner Units | Second
Partners' Equity, Allocations and Cash Distributions
PErcentage of operating surplus (percent)						15.00%
Partners' Capital General Partner Units | Third
Partners' Equity, Allocations and Cash Distributions
PErcentage of operating surplus (percent)						25.00%
Partners' Capital General Partner Units | Thereafter
Partners' Equity, Allocations and Cash Distributions
PErcentage of operating surplus (percent)						50.00%
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 GP LLC | Partners' Capital Common Units
Partners' Equity, Allocations and Cash Distributions
Common units issued in March 2016 Acquisition | $					$ 1,300
Common Stock
Partners' Equity, Allocations and Cash Distributions
Share conversion ratio (in shares)		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) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Unit-Based Compensation
Unit-based compensation expense	$ 314	$ 1,062	$ 1,203
Phantom units | Tranche One
Unit-Based Compensation
Percentage of units vesting	33.33%
Phantom units | Tranche Two
Unit-Based Compensation
Percentage of units vesting	33.33%
Phantom units | Tranche Three
Unit-Based Compensation
Percentage of units vesting	33.33%
Long-Term Incentive Plan | Phantom units
Unit-Based Compensation
Vested shares (in units)	53,091
Weighted average price of vested units (units per share)	$ 11.24
Affiliated Entity | Archrock, Inc.
Unit-Based Compensation
Unit-based compensation expense	$ 100	$ 500	$ 600

Derivatives - Interest Rate Ris

Derivatives - Interest Rate Risk (Details) - Derivatives designated as hedging instruments - USD ($) $ in Millions	Dec. 31, 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	Dec. 31, 2018	Aug. 31, 2017
Interest rate swaps
Accounting for Derivatives
Deferred gains to be reclassified during next 12 months	$ 3.2
Notional amount of interest rate swaps	$ 500
Weighted average interest rate	1.80%
Derivative Expiring In March 2022
Accounting for Derivatives
Notional amount of interest rate swaps	$ 300	$ 300
Derivative liability		$ 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	Dec. 31, 2018	Dec. 31, 2017
Accounting for Derivatives
Derivative asset, net	$ 7,307	$ 4,542
Derivative asset - current
Accounting for Derivatives
Derivative asset	3,185	186
Other long-term assets
Accounting for Derivatives
Derivative asset	4,122	4,490
Derivative liability - current
Accounting for Derivatives
Derivative liability	$ 0	$ (134)

Derivatives - Effect on Deriv_2

Derivatives - Effect on Derivative Instruments on the Income Statement (Details) - Interest rate swaps - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2018	Dec. 31, 2016
Effect of derivative instruments on results of operations
Pre-tax gain (loss) recognized in other comprehensive income (loss)		$ 3,512
Interest expense
Effect of derivative instruments on results of operations
Pre-tax gain (loss) reclassified from accumulated other comprehensive income (loss) into interest expense, net		$ 681
Cash Flow Hedging
Effect of derivative instruments on results of operations
Pre-tax gain (loss) recognized in other comprehensive income (loss)	$ 5,553		$ (3,069)
Pre-tax gain (loss) reclassified from accumulated other comprehensive income (loss) into interest expense, net	$ (3,093)		$ (4,457)

Derivatives - Gain (Loss) Recog

Derivatives - Gain (Loss) Recognized in Income Statement (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Effect of derivative instruments on results of operations
Interest expense, net	$ 90,313	$ 84,291	$ 77,863
Accumulated Other Comprehensive Income (Loss) | Reclassification out of Accumulated Other Comprehensive Income
Effect of derivative instruments on results of operations
Interest expense, net	$ 1,283

Fair Value Measurements (Detail

Fair Value Measurements (Details) - Recurring basis - Level 2 - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Fair value measurements
Interest rate swaps asset	$ 7,307	$ 4,676
Interest rate swaps liability	$ 0	$ (134)

Fair Value Measurements - Narra

Fair Value Measurements - Narratives (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Nonrecurring basis | Level 3
Fair value measurements
Impaired long-lived assets	$ 1	$ 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 Va

Fair Value Measurements Fair Value of Debt (Details) - Fixed Rate Debt [Member] - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Carrying Amount
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Debt	$ 690,001	$ 686,747
Estimate of Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Debt	$ 674,000	$ 702,000

Long-Lived Asset Impairment (De

Long-Lived Asset Impairment (Details) hp in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018USD ($)	Sep. 30, 2018USD ($)	Jun. 30, 2018USD ($)	Mar. 31, 2018USD ($)	Dec. 31, 2017USD ($)	Sep. 30, 2017USD ($)	Jun. 30, 2017USD ($)	Mar. 31, 2017USD ($)	Dec. 31, 2018USD ($)compressor_unithp	Dec. 31, 2017USD ($)compressor_unithp	Dec. 31, 2016USD ($)compressor_unithp
Long-lived asset impairment
Impairment recorded on idle compressor units retired from the active fleet	$ 3,142	$ 3,673	$ 3,846	$ 3,066	$ 4,447	$ 5,368	$ 3,081	$ 6,210	$ 13,727	$ 19,106	$ 46,258
Property, plant and equipment
Long-lived asset impairment
Horsepower of idle compressor units retired from the active fleet (horsepower) | hp										5
Asset impairment charge										$ 1,100
Idle compressor units
Long-lived asset impairment
Idle compressor units retired from the active fleet (compressors) | compressor_unit									170	230	430
Horsepower of idle compressor units retired from the active fleet (horsepower) | hp									57	71	155
Impairment recorded on idle compressor units retired from the active fleet									$ 13,727	$ 17,959	$ 42,460
Additional impairment recorded on available-for-sale compressor units previously culled									$ 0	$ 0	$ 3,798

Restructuring Charges (Details)

Restructuring Charges (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Restructuring and Related Activities [Abstract]
Restructuring charges	$ 0	$ 0	$ 7,309

Income Taxes - Provision for (B

Income Taxes - Provision for (Benefit) from Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Current tax provision:
State	$ 504	$ (2)	$ (32)
Total current	504	(2)	(32)
Deferred tax provision:
State	(29)	3,384	1,444
Total deferred	(29)	3,384	1,444
Provision for income taxes	$ 475	$ 3,382	$ 1,412

Income Taxes - Unrecognized Tax

Income Taxes - Unrecognized Tax Benefit Rollforward (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Beginning balance	$ 6,902	$ 1,882	$ 1,962
Additions based on tax positions related to current year	1,544	1,625	121
Decrease based on tax positions related to prior years (1)	(20)
Additions based on tax positions related to prior years		3,395	0
Reductions based on lapse of statute of limitations	(702)	0	0
Reductions based on settlement payments to (refunds from) government authorities	(1,084)	0	(201)
Ending balance	$ 6,640	$ 6,902	$ 1,882

Income Taxes - Narratives (Deta

Income Taxes - Narratives (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Remeasurement of uncertain tax position		$ 2,500
Unrecognized tax benefits	$ 6,640	6,902	$ 1,882	$ 1,962
Unrecognized tax benefits that would impact tax rate if recognized	3,300	3,600	1,900
Accrued interest expense and penalties	1,200	1,000	100
Income tax expense for interest expense and penalties	200	$ 900	100
Refund from taxing authority	600		1,200
Decrease in uncertain tax position	(1,100)		$ 200
Anticipated decrease to unrecognized tax benefits	$ 1,200

Income Taxes - Reconciliation o

Income Taxes - Reconciliation of Net Income to Partnership Taxable Income (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Effective Income Tax Rate Reconciliation, Other Reconciling Items, Amount
Net income (loss)	$ 23,899	$ 12,613	$ 10,481	$ 10,290	$ 2,633	$ (4,013)	$ 5,275	$ (4,316)	$ 57,283	$ (421)	$ (10,757)
Book/tax depreciation and amortization adjustment									(133,735)	(179,330)	(289,694)
Book/tax long-lived asset impairment									13,727	19,107	46,258
Book/tax adjustment for unit-based compensation expense									314	835	978
Book/tax adjustment for interest rate swap terminations									955	2,410	364
Other temporary differences									9,761	(13,781)	(5,390)
Other permanent differences									2,708	3,422	1,796
U.S. federal partnership taxable loss									(48,987)	$ (167,758)	$ (256,445)
Net tax basis in the entity's assets and liabilities which is less than the reported amounts on the financial statements	$ 700,000								$ 700,000

Commitments and Contingencies (

Commitments and Contingencies (Details) $ in Thousands	Nov. 16, 2018case	Dec. 31, 2018USD ($)claim	Dec. 31, 2018USD ($)claim	Dec. 31, 2017USD ($)
Loss Contingencies
Accrual for income tax liability		$ 3,200	$ 3,200	$ 1,600
Number of claims settled	2		3
Number of claims appealed | claim		3	3
Tax benefit adjustment		$ 10,500
Tax refund receivable		14,000	$ 14,000	$ 0
Judge
Loss Contingencies
Number of claims settled | claim			2
Due to Archrock
Loss Contingencies
Accrued income taxes		3,100	$ 3,100
Accrued liabilities
Loss Contingencies
Accrued income taxes		400	$ 400
Cost of sales (excluding depreciation and amortization)
Loss Contingencies
Tax benefit adjustment		1,800
SG&A
Loss Contingencies
Tax benefit adjustment		8,200
Interest expense
Loss Contingencies
Tax benefit adjustment		100
Other income
Loss Contingencies
Tax benefit adjustment		$ 400

Selected Quarterly Financial _3

Selected Quarterly Financial Data (Unaudited) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Quarterly Financial Information Disclosure [Abstract]
Revenue	$ 160,457	$ 154,033	$ 150,866	$ 147,002	$ 141,762	$ 140,191	$ 138,255	$ 137,295	$ 612,358	$ 557,503	$ 562,360
Gross profit	60,418	57,899	56,683	57,206	49,901	40,420	48,880	41,909
Long-lived asset impairment	3,142	3,673	3,846	3,066	4,447	5,368	3,081	6,210	13,727	19,106	46,258
Merger-related costs	0	2	1,340	1,376					2,718	1	0
Net income (loss)	$ 23,899	$ 12,613	$ 10,481	$ 10,290	$ 2,633	$ (4,013)	$ 5,275	(4,316)	57,283	(421)	(10,757)
Loss on extinguishment of debt								$ 300	$ 0	$ 291	$ 0

SCHEDULE II _ VALUATION AND Q_2

SCHEDULE II — VALUATION AND QUALIFYING ACCOUNTS (Details) - Allowance for Doubtful Accounts - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Movement in Valuation Allowances and Reserves
Balance at Beginning of Period	$ 1,296	$ 1,398	$ 2,463
Charged to Costs and Expenses	1,105	4,104	2,672
Deductions	1,148	4,206	3,737
Balance at End of Period	$ 1,253	$ 1,296	$ 1,398