Third Coast Midstream (AMID) 10-K 7 Mar 16 2015 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2015	Mar. 04, 2016	Jun. 30, 2015
Entity Registrant Name	American Midstream Partners, LP
Entity Central Index Key	1,513,965
Document Type	10-K
Document Period End Date	Dec. 31, 2015
Amendment Flag	false
Document Fiscal Year Focus	2,015
Document Fiscal Period Focus	FY
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Filer Category	Accelerated Filer
Entity Public Float			$ 354,233,679
Limited Partner Common Units
Entity Common Stock, Shares Outstanding		30,889,659
Series A
Entity Common Stock, Shares Outstanding		9,499,370

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Current assets
Cash and cash equivalents	$ 0	$ 499
Accounts receivable	3,181	4,924
Unbilled revenue	15,559	24,619
Risk management assets	365	688
Other current assets	10,094	15,554
Total current assets	29,199	46,284
Property, plant and equipment, net	648,013	582,182
Goodwill	16,262	142,236
Intangible assets, net	100,965	106,306
Investment in unconsolidated affiliates	82,301	22,252
Other assets, net	14,556	14,298
Total assets	891,296	913,558
Current liabilities
Accounts payable	4,667	20,326
Accrued gas purchases	7,281	14,326
Accrued expenses and other current liabilities	25,035	25,800
Current portion of long-term debt	2,338	2,908
Risk management liabilities	0	215
Total current liabilities	39,321	63,575
Asset Retirement Obligations, Noncurrent	28,549	34,645
Other liabilities	1,001	126
Long-term debt	525,100	372,950
Deferred tax liability	5,826	5,113
Total liabilities	$ 599,797	$ 476,409
Commitments and contingencies (see Note 19)
Series A convertible preferred units (9,210 thousand and 5,745 thousand units issued and outstanding as of December 31, 2015 and December 31, 2014, respectively)	$ 169,712	$ 107,965
Equity and partners' capital
General Partner Interest (536 thousand and 392 thousand units issued and outstanding as of December 31, 2015 and December 31, 2014, respectively)	(104,853)	(2,450)
Accumulated other comprehensive income (loss)	40	2
Total partners' capital	117,257	324,467
Noncontrolling interests	4,530	4,717
Total equity and partners' capital	121,787	329,184
Total liabilities, equity and partners' capital	891,296	913,558
Limited Partner Common Units [Member]
Equity and partners' capital
Limited Partners' Capital Account	188,477	294,695
Limited Partner Series B Convertible Units [Member]
Equity and partners' capital
Limited Partners' Capital Account	$ 33,593	$ 32,220

Consolidated Balance Sheets (P

Consolidated Balance Sheets (Parenthetical) - shares	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
General partners' interest units issued	536,000	392,000	185,000
General partners' interest units outstanding	536,000	392,000	185,000
Limited partners, units issued	30,427,000	22,670,000	7,414,000
Limited partners, units outstanding	30,427,000	22,670,000	7,414,000
Series A
Preferred units issued	9,210,000	5,745,000	5,279,000
Preferred units outstanding	9,210,000	5,745,000	5,279,000
Series B
Preferred units issued	1,350,000	1,255,000	0
Preferred units outstanding	1,350,000	1,255,000	0

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Revenue	$ 235,034	$ 307,309	$ 294,051
Gain (loss) on commodity derivatives, net	1,324	1,091	28
Total revenue	236,358	308,400	294,079
Operating expenses:
Purchases of natural gas, NGLs and condensate	105,883	197,952	215,053
Direct operating expenses	59,549	45,702	32,236
Selling, general and administrative expenses	27,232	23,103	19,079
Equity compensation expense	3,774	1,536	2,094
Depreciation, amortization and accretion expense	38,014	28,832	30,002
Total operating expenses	234,452	297,125	298,464
Gain (loss) on involuntary conversion of property, plant and equipment	0	0	343
Gain (loss) on sale of assets, net	(3,011)	(122)	0
Loss on impairment of property, plant and equipment	0	(99,892)	(18,155)
Goodwill, Impairment Loss	(118,592)	0	0
Operating income (loss)	(119,697)	(88,739)	(22,197)
Other income (expense):
Interest expense	(14,745)	(7,577)	(9,291)
Other income (expense)	0	(670)	0
Earnings in unconsolidated affiliates	8,201	348	0
Net income (loss) before income tax (expense) benefit	(126,241)	(96,638)	(31,488)
Income tax (expense) benefit	(1,134)	(557)	495
Net income (loss) from continuing operations	(127,375)	(97,195)	(30,993)
Discontinued operations:
Income (loss) from discontinued operations, net of tax	(80)	(611)	(2,413)
Net income (loss)	(127,455)	(97,806)	(33,406)
Net income (loss) attributable to noncontrolling interests	(25)	(214)	(633)
Net income (loss) attributable to the Partnership	$ (127,480)	$ (98,020)	$ (34,039)
Distribution declared per common unit (a)	$ 1.89	$ 1.85	$ 1.75
Basic and diluted:
Income (Loss) from Continuing Operations, Per Outstanding Limited Partnership Unit, Basic	(6)	(8.54)	(7.15)
Limited Partners' net income (loss) from discontinued operations per unit (basic and diluted)	0	(0.04)	(0.27)
Limited partners’ net income (loss) per unit (basic and diluted)	$ (6)	$ (8.58)	$ (7.42)
Weighted average number of common units outstanding:
Basic and diluted	24,983	13,472	7,525
Total Partners Capital
Discontinued operations:
Net income (loss) attributable to the Partnership	$ (127,480)	$ (98,020)	$ (34,039)
General Partner Interest
Discontinued operations:
General Partner's Interest in net income (loss)	(1,645)	(1,279)	(1,405)
Limited Partner [Member]
Discontinued operations:
Limited Partners' Interest in net income (loss)	$ (125,835)	$ (96,741)	$ (32,634)

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ (127,455)	$ (97,806)	$ (33,406)
Unrealized gain (loss) on postretirement benefit plan assets and liabilities	38	(102)	(247)
Comprehensive income (loss)	(127,417)	(97,908)	(33,653)
Net income (loss) attributable to noncontrolling interests	(25)	(214)	(633)
Comprehensive income (loss) attributable to Partnership	$ (127,442)	$ (98,122)	$ (34,286)

Consolidated Statements of Chan

Consolidated Statements of Changes in Partners' Capital and Noncontrolling Interest - USD ($)	Total	General Partner Interest	Limited Partner Interest	Series B	Accumulated Other Comprehensive Income	Total Partners Capital	Blackwater [Member]	Noncontrolling Interest	Blackwater [Member]	Blackwater [Member]General Partner Interest	Blackwater [Member]Limited Partner Interest	Blackwater [Member]Total Partners Capital	Series B	Series BSeries B	Series BAccumulated Other Comprehensive Income	Series BTotal Partners Capital	Series BNoncontrolling Interest
Beginning Balance at Dec. 31, 2012		$ 548,000	$ 79,266,000		$ 351,000	$ 80,165,000		$ 7,438,000
Noncontrolling Interest, Decrease from Redemptions or Purchase of Interests		37,000	1,993,000			2,030,000		2,782,000
General Partner's Interest in net income (loss)		(1,405,000)
Limited Partners' Interest in net income (loss)			(32,634,000)
Net income (loss)	$ (34,039,000)					(34,039,000)		633,000
Issuance of common units, net of offering costs	54,900,000		54,853,000
Unit holder contributions		12,500,000				12,500,000	$ 22,696,000					$ 22,696,000
Unitholder distributions	(16,120,000)	(623,000)	(21,628,000)			(22,251,000)			$ (27,650,000)	$ (30,702,000)			$ 0
General Partner Noncash Distributions											$ 3,052,000
Fair value of Series A Units in excess of High Point System net assets received	(15,612,000)	312,000	15,300,000			15,612,000
Net distributions to noncontrolling interest owners								(661,000)
LTIP vesting		(2,067,000)	2,067,000
Tax netting repurchase	630,000		(630,000)			(630,000)
Unit based compensation		2,024,000				2,024,000
Other comprehensive income (loss)	(247,000)				(247,000)	(247,000)
Ending Balance at Dec. 31, 2013		2,696,000	71,039,000		104,000	73,839,000		4,628,000
Noncontrolling Interest, Decrease from Redemptions or Purchase of Interests		0	21,000			21,000		189,000
General Partner's Interest in net income (loss)		(1,279,000)
Limited Partners' Interest in net income (loss)			(96,741,000)
Net income (loss)	(98,020,000)					(98,020,000)
Net Income (loss) attributable to noncontrolling interests								214,000
Issuance of common units, net of offering costs	119,300,000		351,551,000			351,551,000
Issuance of Series B Units														$ 32,220,000
Unit holder contributions		5,678,000	0		0	5,678,000
Unitholder distributions	(28,009,000)	(2,913,000)	(39,150,000)			(42,063,000)							(2,220,000)
Fair value of Series A Units in excess of High Point System net assets received	0
Issuance and exercise of warrants		(7,164,000)	7,164,000
Net distributions to noncontrolling interest owners		0	0		0	0		(314,000)
LTIP vesting		(824,000)	1,067,000			243,000
Tax netting repurchase	256,000		256,000			256,000
Unit based compensation		1,356,000				1,356,000
Other comprehensive income (loss)	(102,000)				(102,000)	(102,000)
Ending Balance at Dec. 31, 2014	324,467,000	(2,450,000)	294,695,000	$ 32,220,000	2,000	324,467,000		4,717,000
Noncontrolling Interest, Decrease from Redemptions or Purchase of Interests		0	20,000	0	0	20,000		172,000
General Partner's Interest in net income (loss)		(1,645,000)
Limited Partners' Interest in net income (loss)			(125,835,000)
Net income (loss)	(127,480,000)					(127,480,000)		25,000
Issuance of common units, net of offering costs		0	82,421,000	0	0			0
Issuance of Series B Units			0											$ 1,373,000	$ 0	$ 1,373,000	$ 0
Unit holder contributions		1,996,000	0	0		1,996,000		0
Unitholder distributions	(53,386,000)	(7,023,000)	(64,714,000)			(71,737,000)	500,000						$ (1,373,000)
Partners Capital Account Distributions, Delta House		(96,297,000)					$ 27,700,000
Fair value of Series A Units in excess of High Point System net assets received	0
Net distributions to noncontrolling interest owners		0	0	0	0	0		(40,000)
LTIP vesting		(2,490,000)	2,686,000			196,000
Tax netting repurchase	756,000		(756,000)	0		(756,000)
Unit based compensation		3,056,000	0	0	0	3,056,000		0
Other comprehensive income (loss)	38,000				38,000	38,000
Ending Balance at Dec. 31, 2015	$ 117,257,000	$ (104,853,000)	$ 188,477,000	$ 33,593,000	$ 40,000	$ 117,257,000		$ 4,530,000

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Cash flows from operating activities
Net income (loss)	$ (127,455)	$ (97,806)	$ (33,406)
Depreciation, Depletion and Amortization	38,014	28,832	30,002
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation, amortization and accretion expense		28,832	29,999
Amortization of deferred financing costs	1,482	2,212	1,334
Amortization of weather derivative premium	912	1,035	662
Unrealized (gain) loss on derivative contracts, net	71	(595)	1,505
Non-cash compensation	3,863	1,626	2,094
Postretirement expense (benefit)	(14)	(45)	(73)
(Gain) loss on involuntary conversion of property, plant and equipment	0	0	(343)
(Gain) loss on sale of assets, net	3,161	207	75
Loss on impairment of property, plant and equipment	0	99,892	18,155
Loss on impairment of noncurrent assets held for sale	0	673	2,400
Loss on impairment of goodwill	118,592	0	0
Earnings in unconsolidated affiliates	(8,201)	(348)	0
Distributions from unconsolidated affiliates	8,201	348	0
Deferred tax expense (benefit)	953	213	(847)
Changes in operating assets and liabilities, net of effects of assets acquired and liabilities assumed:
Accounts receivable	1,743	13,067	(790)
Unbilled revenue	9,060	2,272	(226)
Risk management assets and liabilities	(875)	(809)	(1,147)
Other current assets	(962)	(7,533)	(1,614)
Other assets, net	(522)	6,049	(823)
Accounts payable	(3,643)	(12,026)	(845)
Accrued gas purchases	(7,045)	(5,540)	462
Accrued expenses and other current liabilities	2,857	(9,149)	769
Asset retirement obligations	(90)	(1,030)	0
Other liabilities	835	(67)	(118)
Net cash provided by operating activities	40,937	21,478	17,223
Net cash provided by operating activities
Cost of acquisitions, net of cash acquired and settlements	(7,383)	362,316	0
Additions to property, plant and equipment	(130,549)	(96,998)	(27,196)
Proceeds from disposal of property, plant and equipment	4,813	6,323	500
Insurance proceeds from involuntary conversion of property, plant and equipment	0	0	482
Investment in unconsolidated affiliates	(71,597)	(12,000)	0
Proceeds from equity method investment, return of capital	12,367	1,632	0
Restricted cash	6,475	(8,511)	(2,000)
Net cash used in investing activities	(171,108)	(471,870)	(28,214)
Cash flows from financing activities
Proceeds from issuance of common units to public, net of offering costs	82,488	204,255	54,853
Unitholder contributions	1,905	5,588	13,075
Payments of Distributions to Affiliates	(53,386)	(28,009)	(16,120)
Issuance of Units	44,768	0	14,393
Acquisition of noncontrolling interests	(74)	(8)	(752)
LTIP tax netting unit repurchase	(756)	(256)	(630)
Deferred financing costs	(2,238)	(3,841)	(2,113)
Payments on other debt	(3,557)	(2,589)	(2,640)
Borrowings on other debt	4,709	3,449	3,795
Payments on loan to affiliate	0	0	(20,000)
Payments on bank loans	0	0	(34,730)
Borrowings on bank loans	0	0	27,546
Payments on long-term debt	(189,150)	(250,870)	(131,571)
Borrowings on long-term debt	341,300	493,085	134,021
Net cash provided by financing activities	129,672	450,490	10,816
Net increase (decrease) in cash and cash equivalents	(499)	98	(175)
Cash and cash equivalents
Beginning of period	499	401	576
End of period	0	499	401
Supplemental cash flow information
Interest payments, net	12,013	6,726	6,416
Supplemental non-cash information
(Decrease) increase in accrued property, plant and equipment	25,637	(31,390)	5,181
Fair value of Series A Units in excess of net assets received	0	0	15,612
Accrued and paid-in-kind unitholder distribution for Series A Units			4,811
Dividends, Paid-in-kind			0
Blackwater [Member]
Cash flows from financing activities
Unitholder distributions for common control transactions	(96,297)	0	(27,650)
Supplemental non-cash information
Noncash or Part Noncash Acquisition, Net Nonmonetary Assets Acquired (Liabilities Assumed)	0	0	22,121
ArcLight [Member]
Supplemental non-cash information
Noncash or Part Noncash Acquisition, Net Nonmonetary Assets Acquired (Liabilities Assumed)	0	0	59,995
Noncontrolling Interest
Cash flows from financing activities
Net distributions to noncontrolling interests	(40)	(314)	(661)
Series B
Cash flows from financing activities
Issuance of Units	0	30,000	$ 0
Series A
Supplemental non-cash information
Accrued and paid-in-kind unitholder distribution for Series A Units	16,978	13,154
Dividends, Paid-in-kind	1,373	2,220
Costar Midstream, L.L.C. [Member]
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Loss on impairment of goodwill	95,000
Supplemental non-cash information
Common unit issuance related to Costar Acquisition	$ 0	$ 147,296

Organization and Basis of Prese

Organization and Basis of Presentation	12 Months Ended
	Dec. 31, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization and Basis of Presentation	Organization, Basis of Presentation and Summary of Significant Accounting Policies General American Midstream Partners, LP (the "Partnership"), was formed on August 20, 2009 as a Delaware limited partnership for the purpose of operating, developing and acquiring a diversified portfolio of midstream energy assets. The Partnership's general partner, American Midstream GP, LLC (the "General Partner"), is 95% owned by High Point Infrastructure Partners, LLC ("HPIP") and 5% owned by AIM Midstream Holdings, LLC. We hold our assets primarily in a number of wholly owned limited liability companies, two limited partnerships and a corporation. Our capital accounts consist of notional general partner units and limited partner interests. Nature of business We are engaged in the business of gathering, treating, processing, and transporting natural gas; gathering, transporting, storing, treating and fractionating NGLs; gathering, storing and transporting crude oil and condensates; and storing specialty chemical products, all through our ownership and operation of twelve gathering systems, five processing facilities, three fractionation facilities, three marine terminal sites, three interstate pipelines, five intrastate pipelines and one crude oil pipeline. We also own a 66.7% non-operated interest in Main Pass Oil Gathering Company ("MPOG"), a crude oil gathering and processing system; a 50% undivided, non-operated interest in the Burns Point Plant, a natural gas processing plant; a 46% non-operated interest in Mesquite, an off-spec condensate fractionation project; and a 12.9% non-operated indirect interest in the Delta House floating production system and related pipeline infrastructure ("Delta House"). Our primary assets, which are strategically located in Alabama, Georgia, Louisiana, Mississippi, North Dakota, Tennessee, Texas and the Gulf of Mexico, provide critical infrastructure that links producers of natural gas, crude oil, NGLs, condensate and specialty chemicals to numerous intermediate and end-use markets. We currently operate more than 3,000 miles of pipelines that gather and transport over 1 Bcf/d of natural gas and operate approximately 1.8 million barrels of storage capacity across three marine terminal sites. Basis of presentation We have prepared the accompanying consolidated financial statements in accordance with accounting principles generally accepted in the United States of America ("GAAP"). The results of operations for acquisitions accounted for as business combinations have been included in the consolidated financial statements since their respective acquisition dates. See Note 2 "Acquisitions and Divestitures" for further information. Transactions Between Entities Under Common Control We may enter into transactions with our General Partner and affiliates whereby we receive a contribution of midstream assets or subsidiaries in exchange for consideration from the Partnership. We account for the net assets received using the historical book value of the asset or subsidiary being contributed or transferred as these are transactions between entities under common control. Our historical financial statements may be revised to include the results attributable to the assets contributed from our General Partner as if we owned such assets for all periods presented by the Partnership since either the change in control of our General Partner, effective April 15, 2013 or later. Consolidation policy The accompanying consolidated financial statements include accounts of American Midstream Partners, LP, and its controlled subsidiaries. All significant inter-company accounts and transactions have been eliminated in the preparation of the accompanying consolidated financial statements. Investment in Unconsolidated Affiliates Equity investments in which the Partnership exercises significant influence, but does not control and is not the primary beneficiary, are accounted for using the equity method and are reported in Investment in unconsolidated affiliates in the accompanying consolidated balance sheets. The Partnership believes the equity method is an appropriate means for it to recognize increases or decreases measured by GAAP in the economic resources underlying the investments. Regular evaluation of these investments is appropriate to evaluate any potential need for impairment. The Partnership uses evidence of a loss in value to identify if an investment has declined in value, other than a temporary decline. The Partnership accounts for its 66.7% non-operated interest in MPOG, its 46.0% non-operated interest in Mesquite and its 12.9% non-operated indirect interest in Delta House under the equity method. Use of estimates When preparing consolidated financial statements in conformity with GAAP, management must make estimates and assumptions based on information available at the time. These estimates and assumptions affect the reported amounts of assets, liabilities, revenues and expenses, as well as the disclosures of contingent assets and liabilities as of the date of the financial statements. Estimates and assumptions are based on information available at the time such estimates and assumptions are made. Adjustments made with respect to the use of these estimates and assumptions often relate to information not previously available. Uncertainties with respect to such estimates and assumptions are inherent in the preparation of financial statements. Estimates and assumptions are used in, among other things, i) estimating unbilled revenues, product purchases and operating and general and administrative costs, ii) developing fair value assumptions, including estimates of future cash flows and discount rates, iii) analyzing long-lived assets, goodwill and intangible assets for possible impairment, iv) estimating the useful lives of assets and v) determining amounts to accrue for contingencies, guarantees and indemnifications. Actual results, therefore, could differ materially from estimated amounts. Cash and cash equivalents We consider all highly liquid investments with an original maturity of three months or less at the date of purchase to be cash equivalents. The carrying value of cash and cash equivalents approximates fair value because of the short term to maturity of these investments. Allowance for doubtful accounts We establish provisions for losses on accounts receivable when we determine that we will not collect all or part of an outstanding balance. Collectability is reviewed regularly and an allowance is established or adjusted, as necessary, using the specific identification method. As of December 31, 2015 and 2014 , the Partnership recorded no allowances for losses on accounts receivable. Operational balancing agreements and natural gas imbalances To facilitate deliveries of natural gas and provide for operational flexibility, we have operational balancing agreements in place with other interconnecting pipelines. These agreements ensure that the volume of natural gas a shipper schedules for transportation between two interconnecting pipelines equals the volume actually delivered. If natural gas moves between pipelines in volumes that are more or less than the volumes the shipper previously scheduled, a natural gas imbalance is created. The imbalances are settled through periodic cash payments or repaid in-kind through future receipt or delivery of natural gas. Natural gas imbalances are recorded as gas imbalances and classified within Other current assets or Other current liabilities on our consolidated balance sheets at cost which approximates fair value. Derivative financial instruments Our net income (loss) and cash flows are subject to volatility stemming from changes in interest rates on our variable rate debt, commodity prices and fractionation margins (the relative difference between the price we receive from NGL sales and the corresponding cost of natural gas purchases). In an effort to manage the risks to unitholders, we use a variety of derivative financial instruments including swaps, collars and interest rate caps to create offsetting positions to specific commodity or interest rate exposures. In accordance with the authoritative accounting guidance, we record all derivative financial instruments in our consolidated balance sheets at fair value as current and long-term assets or liabilities on a net basis by counterparty. We record changes in the fair value of our derivative financial instruments in our consolidated statements of operations as follows: • Commodity-based derivatives: "Total revenue" • Corporate interest rate derivatives: "Interest expense" Our formal hedging program provides a control structure and governance for our hedging activities specific to identified risks and time periods, which are subject to the approval and monitoring by the Board of Directors of our General Partner. We employ derivative financial instruments in connection with an underlying asset, liability or anticipated transaction, and we do not use derivative financial instruments for speculative or trading purposes. The price assumptions we use to value our derivative financial instruments can affect net income (loss) for each period. We use published market price information where available, or quotations from over-the-counter, or OTC, market makers to find executable bids and offers. The valuations also reflect the potential impact of conditions, including credit risk of our counterparties. The amounts reported in our consolidated financial statements change quarterly as these valuations are revised to reflect actual results, changes in market conditions or other factors, many of which are beyond our control. Fair value measurements We apply the authoritative accounting provisions for measuring fair value of our derivative instruments and disclosures associated with our outstanding indebtedness. We define fair value as an exit price representing the expected amount we would receive when selling an asset or pay to transfer a liability in an orderly transaction with market participants at the measurement date. We use various assumptions and methods in estimating the fair values of our financial instruments. The carrying amounts of cash and cash equivalents, accounts receivable and accounts payable approximated their fair value due to the short-term maturity of these instruments. The carrying amount of our various credit facilities approximate fair value, because the interest rates on these facilities are variable. We employ a hierarchy which prioritizes the inputs we use to measure recurring fair value into three distinct categories based upon whether such inputs are observable in active markets or unobservable. We classify assets and liabilities in their entirety based on the lowest level of input that is significant to the fair value measurement. Our methodology for categorizing assets and liabilities that are measured at fair value pursuant to this hierarchy gives the highest priority to unadjusted quoted prices in active markets and the lowest level to unobservable inputs as outlined below: • Level 1 – Inputs represent unadjusted quoted prices in active markets for identical assets or liabilities; • Level 2 – Inputs include quoted prices for similar assets and liabilities in active markets that are either directly or indirectly observable; and • Level 3 – Inputs are unobservable and considered significant to fair value measurement. We utilize a mid-market pricing convention, or the "market approach," for valuation for assigning fair value to our derivative assets and liabilities. Our credit exposure for over-the-counter derivatives is directly with our counterparty and continues until the maturity or termination of the contracts. As appropriate, valuations are adjusted for various factors such as credit and liquidity considerations. Property, plant and equipment We capitalize expenditures related to property, plant and equipment that have a useful life greater than one year for assets purchased or constructed; existing assets that are replaced, improved, or the useful lives of which have been extended; and all land, regardless of cost. Maintenance and repair costs, including any planned major maintenance activities, are expensed as incurred. We record property, plant, and equipment at its original cost, which we depreciate on a straight-line basis over its estimated useful life. Our determination of the useful lives of property, plant and equipment requires us to make various assumptions, including the supply of and demand for hydrocarbons in the markets served by our assets, normal wear and tear of the facilities, and the extent and frequency of maintenance programs. We record depreciation using the group method of depreciation, which is commonly used by pipelines, utilities and similar assets. We classify long-lived assets to be disposed of through sales that meet specific criteria as held for sale. We cease depreciating those assets effective on the date the asset is classified as held for sale. We record those assets at the lower of their carrying value or the estimated fair value less the cost to sell. Until the assets are disposed of, an estimate of the fair value is re-determined when related events or circumstances change. Impairment of long lived Assets We evaluate the recoverability of our property, plant and equipment and intangible assets with definite lives when events or circumstances indicate we may not recover the carrying amount of the assets. We continually monitor our operations, the market, and business environment to identify indicators that could suggest an asset or asset group may not be recoverable. We evaluate the asset or asset group for recoverability by estimating the undiscounted future cash flows expected to be derived from their use and disposition. These cash flow estimates require us to make projections and assumptions for many years into the future for pricing, demand, competition, operating cost, contract renewals, and other factors. An asset or asset group is considered impaired when the estimated undiscounted cash flows are less than the carrying amount. In that event, an impairment loss is recognized to the extent that the carrying amount of the asset or asset group exceeds its fair value as determined by quoted market prices in active markets or present value techniques. The determination of fair values using present value techniques requires us to make projections and assumptions regarding future cash flows and weighted average cost of capital. Any changes we make to these projections and assumptions could result in significant revisions to our evaluation of the recoverability of our property, plant and equipment and the recognition of an impairment loss in our consolidated statements of operations. Goodwill and intangible assets We record goodwill for the excess of the cost of an acquisition over the fair value of the net assets of the acquired business. Goodwill is not amortized but is reviewed for impairment at least annually or more frequently if an event or change in circumstance indicates that an impairment may have occurred. We first assess qualitative factors to evaluate whether it is more likely than not that an impairment has occurred and it is therefore necessary to perform the two-step goodwill impairment test. If the two-step goodwill impairment test indicates that the goodwill is impaired, an impairment loss is recorded. We record the estimated fair value of acquired customer contracts, relationships and dedicated acreage agreements as intangible assets. These intangible assets have definite lives and are subject to amortization on a straight-line basis over their economic lives, currently ranging between 10 years and 30 years . We assess intangible assets for impairment together with related underlying long-lived assets whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. Deferred financing costs Costs incurred in connection with our revolving credit facility are deferred and charged to interest expense over the term of the related credit arrangement. Gains or losses on debt repurchase and debt extinguishment include any associated unamortized deferred financing costs. Asset retirement obligations ("AROs") AROs are legal obligations associated with the retirement of tangible long-lived assets that result from the asset's acquisition, construction, development and operation. An ARO is initially measured at its estimated fair value. Upon initial recognition, we also record an increase to the carrying amount of the related long-lived asset. We depreciate the asset using the straight-line method over the period during which it is expected to provide benefits. After initial recognition, we revise the ARO to reflect the passage of time and for changes in the estimated amount or timing of cash flows. We have legal obligations requiring us to decommission our offshore pipeline systems at retirement. In certain rate jurisdictions, we are permitted to include annual charges for removal costs in the regulated cost of service rates we charge our customers. Additionally, legal obligations exist for a minority of our offshore right-of-way agreements due to requirements or landowner options to compel us to remove the pipe at final abandonment. Sufficient data exists with certain onshore pipeline systems to reasonably estimate the cost of abandoning or retiring a pipeline system. However, in some cases, there is insufficient information to reasonably determine the timing and/or method of settlement of estimating the fair value of the asset retirement obligation. In these cases, the asset retirement obligation cost is considered indeterminate because there is no data or information that can be derived from past practice, industry practice, management's experience, or the asset's estimated economic life. The useful lives of most pipeline systems are primarily derived from available supply resources and ultimate consumption of those resources by end users. Variables can affect the remaining lives of the assets which preclude us from making a reasonable estimate of the asset retirement obligation. Indeterminate asset retirement obligation costs will be recognized in the period in which sufficient information exists to reasonably estimate potential settlement dates and methods. Commitments, contingencies and environmental liabilities We expense or capitalize, as appropriate, expenditures for ongoing compliance with environmental regulations that relate to past or current operations. We expense amounts we incur from the remediation of existing environmental contamination caused by past operations that do not benefit future periods by preventing or eliminating future contamination. We record liabilities for environmental matters when assessments indicate that remediation efforts are probable and the costs can be reasonably estimated. Estimates of environmental liabilities are based on currently available facts, existing technology and presently enacted laws and regulation taking into consideration the likely effects of inflation and other factors. These amounts also take into account our prior experience in remediating contaminated sites, other companies' clean-up experience and data released by government organizations. Our estimates are subject to revision in future periods based on actual cost or new information. We evaluate recoveries from insurance coverage separately from the liability and, when recovery is probable, we record an asset separately from the associated liability in our consolidated financial statements. We recognize liabilities for other commitments and contingencies when, after fully analyzing the available information, we determine it is either probable that an asset has been impaired or that a liability has been incurred and the amount of impairment or loss can be reasonably estimated. When a range of probable loss can be estimated, we accrue the most likely amount or if no amount is more likely than another, we accrue the minimum of the range of probable loss. We expense legal costs associated with loss contingencies as such costs are incurred. Noncontrolling interests Noncontrolling interests represent the minority interest holders' proportionate share of the equity of the respective systems. Noncontrolling interests are adjusted for the minority interest holders' proportionate share of the earnings or losses. Management reports noncontrolling interest in the Chatom system in the financial statements pursuant to paragraph ASC 810-10-65-1. The 7.8% noncontrolling interest is held by non-affiliated working interest owners. Revenue recognition and the estimation of revenues and cost of purchases We recognize revenue when all of the following criteria are met: i) persuasive evidence of an exchange arrangement exists, ii) delivery has occurred or services have been rendered, iii) the price is fixed or determinable, and iv) collectability is reasonably assured. We record revenue and cost of product sold on a gross basis for those transactions where we act as the principal and take title to natural gas, crude oil, NGLs or condensates that are purchased for resale. When our customers pay us a fee for providing a service such as gathering, treating, transportation or storage, we record those fees separately in revenues. Equity-based compensation We award equity-based compensation to management, non-management employees and directors under our Long-Term Incentive Plan ("LTIP"), which provides for the issuance of options, unit appreciation rights, restricted units, phantom units, other unit-based awards, unit awards or replacement awards, as well as tandem Distribution Equivalent Rights ("DERs"). Compensation expense is measured by the fair value of the award at the date of grant as determined by management. Compensation expense is recognized in Equity compensation expense over the requisite service period of each award. Income taxes The Partnership is not a taxable entity for U.S. federal income tax purposes or for the majority of states that impose an income tax. Taxes on our net income are generally borne by our unitholders through the allocation of taxable income. American Midstream Blackwater, LLC, a subsidiary of the Partnership, owns a subsidiary that has operations which are subject to both federal and state income taxes. We account for income taxes of that subsidiary using an asset and liability approach for financial accounting and reporting of income taxes. If it is more than likely that a deferred tax asset will not be realized, a valuation allowance is recognized. Certain tax expense results from the enactment of laws by the State of Texas that apply to entities organized as partnerships and is included in Income tax (expense) benefit in our consolidated statements of operations. The Texas margin tax is computed on our taxable margin apportioned to Texas annually. Net income (loss) for financial statement purposes may differ significantly from taxable income (loss) allocable to unitholders as a result of differences between the financial reporting and income tax bases of our assets and liabilities and the taxable income allocation requirement under our Partnership Agreement. The aggregate difference in the basis of our net assets for financial and tax reporting purposes cannot be readily determined because information regarding each partner's tax attributes in us is not available. Accumulated other comprehensive income (loss) Accumulated other comprehensive income (loss) is comprised solely of adjustments related to the Partnership's postretirement benefit plan. Limited partners' net income (loss) per unit We compute earnings per unit using the two-class method. The two-class method requires that securities that meet the definition of a participating security be considered for inclusion in the computation of basic earnings per unit. Under the two-class method, earnings per unit is calculated as if all of the earnings for the period were distributed under the terms of the Partnership Agreement, regardless of whether the General Partner has discretion over the amount of distributions to be made in any particular period, whether those earnings would actually be distributed during a particular period from an economic or practical perspective, or whether the General Partner has other legal or contractual limitations on its ability to pay distributions that would prevent it from distributing all of the earnings for a particular period. The two-class method does not impact our overall net income or other financial results; however, in periods in which aggregate net income exceeds our aggregate distributions for such period, it will have the impact of reducing net income per limited partner unit. This result occurs as a larger portion of our aggregate earnings, as if distributed, is allocated to the incentive distribution rights of the General Partner, even though we make distributions on the basis of available cash and not earnings. In periods in which our aggregate net income does not exceed our aggregate distributions for such period, the two-class method does not have any impact on our calculation of earnings per limited partner unit. Recent Accounting Pronouncements In May 2014, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") No. 2014-09, Revenue from Contracts with Customers (Topic 606), which amends the existing accounting standards for revenue recognition. The standard requires an entity to recognize revenue in a manner that depicts the transfer of goods or services to customers at an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. ASU 2015-14 was subsequently issued and deferred the effective date to annual reporting periods beginning after December 15, 2017, including interim reporting periods within that period. We are currently evaluating the method of adoption and impact this standard will have on our consolidated financial statements and related disclosures. In February 2015, the FASB issued ASU No. 2015-02, Consolidation - Amendments to the Consolidation Analysis, which amends the current consolidation guidance. The amendments affect both the variable interest entity ("VIE") and voting interest entity ("VOE") consolidation models. The standard is effective for public reporting entities in the fiscal periods beginning after December 15, 2015, early adoption is permitted. The Partnership has evaluated the impact of this standard on its consolidated financial statements and determined it will not have a material impact. In April 2015, the FASB issued ASU No. 2015-03, Simplifying the Presentation of Debt Issuance Costs. This amendment requires that debt issuance costs related to a recognized debt liability be presented in the balance sheet as a direct deduction from the carrying amount of that debt liability, consistent with debt discounts. ASU 2015-03 is effective for fiscal years beginning after December 15, 2015, including interim periods therein, and is applied retrospectively. Early adoption is permitted for financial statements that have not been previously issued. ASU 2015-15, Presentation and Subsequent Measurement of Debt Issue Costs Associated with Line of Credit Arrangements, was subsequently issued to address the absence of authoritative guidance for debt issuance costs related to line-of-credit arrangements and states that the Securities and Exchange Commission ("SEC") staff will not object to an entity deferring and presenting debt issuance costs as an asset and subsequently amortizing the deferred debt issuance costs ratably over the term of the line-of-credit arrangement. Given the Partnership's debt issuance costs relate to its Credit Agreement (as defined in Note 13 "Debt Obligations"), the Partnership is not required to alter its current accounting for such costs. In April 2015, the FASB issued ASU No. 2015-05, Intangibles — Goodwill and Other — Internal-Use Software (Subtopic 350-40) , which assists entities in evaluating the accounting for fees paid by a customer in a cloud computing arrangement by providing guidance as to whether an arrangement includes the sales or license of software. The amendment will be effective prospectively for reporting periods beginning on or after December 15, 2015, and early adoption is permitted. The Partnership has evaluated the impact of this standard on its financial statements and determined it will not have a material impact. In April 2015, the FASB issued ASU No. 2015-06, Earnings Per Share (Topic 260) . This guidance clarifies the process for updating historical earnings per unit disclosures when a drop-down transaction occurs between entities under common control. Pursuant to the amendment, the earnings (losses) of a transferred business before the date of a dropdown transaction should be allocated entirely to the general partner. Additionally, the previously reported earnings per unit measure presented in the historical financial statements would not change as a result of the drop-down transaction. ASU 2015-06 is effective for annual reporting periods beginning after December 15, 2015, and for interim periods within those fiscal years. Early adoption is permitted. The Partnership has evaluated this guidance and determined it will not have a material impact. In September 2015, the FASB issued ASU No. 2015-16, Business Combinations (Topic 805). This amendment requires that an acquirer recognize adjustments to provisional amounts that are identified during the measurement period in the reporting period in which the adjustment amounts are determined. ASU 2015-16 is effective for fiscal years beginning after December 15, 2015, including interim periods within those fiscal years. Early adoption is permitted for financial statements that have not been issued. The Partnership has evaluated this guidance and determined it is consistent with our policy and historical presentation. In November 2015, the FASB issued ASU 2015-17, Income Taxes (Topic 740). This amendment requires that deferred tax liabilities and assets be classified as noncurrent. ASU 2015-17 is effective for fiscal years beginning after December 15, 2016, including interim periods within those fiscal years. Early adoption is permitted. The Partnership has evaluated this guidance and elected to adopt this amendment for the fiscal year ended December 31, 2015. As such, the Partnership’s deferred tax liabilities and assets have been classified as noncurrent in the consolidated balance sheets as of December 31, 2015, and 2014. In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842). This amendment requires the recognition of lease assets and lease liabilities by lessees for those leases classified as operating leases under previous GAAP. ASU 2016-02 is effective for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. Early adoption is permitted. We are currently evaluating the method of adoption and impact this standard will have on our consolidated financial statements and related disclosures.

Acquisitions

Acquisitions	12 Months Ended
	Dec. 31, 2015
Business Combinations [Abstract]
Acquisitions	Acquisitions and Divestitures Delta House Investment On September 18, 2015, the Partnership acquired a 26.3% interest in Pinto Offshore Holdings, LLC ("Pinto") (the "Delta House Investment"), an entity that owns a non-operated interest in (i) approximately 49% of the limited liability company interests of Delta House FPS LLC and (ii) approximately 49% of the limited liability company interests of Delta House Oil and Gas Lateral LLC, which respectively own Delta House floating production system and related pipeline infrastructure. Delta House is a floating production system platform with associated crude oil and gas export pipelines, located in the Mississippi Canyon region of the deepwater Gulf of Mexico. We acquired our 26.3% non-operated interest in Pinto in exchange for $162.0 million in cash, funded by the proceeds of a public offering of 7.5 million of the Partnership's common units representing Limited Partner interests, or common units, and with borrowings under the Partnership's Credit Agreement. As a result, we own a minority interest in Pinto, which represents an indirect 12.9% interest in Delta House. Pursuant to the Pinto LLC Agreement, we have no management control or authority over the day-to-day operations. Our interest in Pinto is accounted for as an equity method investment in the consolidated financial statements. Because our interest in Delta House was previously owned by an affiliate of our General Partner, we have accounted for our investment at our affiliate's final carry-over basis resulting in $65.7 million which is recorded in Investments in unconsolidated affiliates in our consolidated balance sheets and as an investing activity within the related consolidated statement of cash flows. The amount by which the total consideration exceeded the carry-over basis was $96.3 million and is recorded as a distribution within the consolidated statements of changes in partners’ capital and noncontrolling interest and a financing activity in the consolidated statement of cash flows. For the year ended December 31, 2015 , the Partnership recorded $7.5 million in earnings from its indirect interest in Delta House and also received cash distributions of $16.6 million from Delta House. The excess of the cash distributions received over the earnings recorded is classified as a return of capital within cash flows from investing activities in our consolidated statement of cash flows. Costar Acquisition On October 14, 2014, the Partnership acquired 100% of the membership interests of Costar Midstream, L.L.C. ("Costar") from Energy Spectrum Partners VI LP and Costar Midstream Energy, LLC, in exchange for $258.0 million in cash and 6.9 million of the Partnership's common units ("the Costar Acquisition"). Costar is an onshore gathering and processing company with its primary gathering, processing, fractionation, and off-spec condensate treating and stabilization assets in East Texas and the Permian basin, with a significant crude oil gathering system project in the Bakken oil play. The Costar Acquisition was accounted for using the acquisition method of accounting and as a result, the aggregate purchase price was allocated to the assets acquired, liabilities assumed and a noncontrolling interest in a Costar subsidiary based on their respective fair values as of the acquisition date. The excess of the aggregate purchase price of the fair values of the assets acquired, liabilities assumed and the noncontrolling interest was classified as goodwill, which is attributable to future prospective customer agreements expected to be obtained as a result of the acquisition. The operating systems acquired have been included in the Partnership’s Gathering and Processing segment from the acquisition date. The following table summarizes the fair value of consideration transferred to acquire Costar and the allocation of that amount to the assets acquired, liabilities assumed and the noncontrolling interest for the Costar Acquisition based upon their respective fair values as of the acquisition date (in thousands). Fair value of consideration transferred (in thousands): Cash $ 258,001 Limited partner common units 147,296 Total fair value of consideration $ 405,297 Fair Value of assets acquired, liabilities assumed and noncontrolling interest (in thousands): Working capital $ 8,152 Property, plant and equipment: Processing plants $ 48,357 Pipelines 128,799 Land 1,244 Buildings 682 Equipment 9,827 Construction in progress 16,146 Total property, plant and equipment 205,055 Investment in unconsolidated affiliate 11,884 Intangible assets: Customer relationships 53,400 Dedicated acreage 32,000 Goodwill 95,025 Noncontrolling interest (219 ) $ 405,297 The fair value of the common units issued for the Costar Acquisition, $147.3 million , differs from the market price of such units on the date of the acquisition as a result of restrictions which require the sellers to hold the units for specified periods of time. The fair value of limited partner units issued in the transaction was determined using an option pricing model and the following key assumptions: i) the closing common unit market price on the day of the acquisition, ii) the contractual holding periods, iii) historical common unit price volatility for the Partnership and its peers, and iv) a risk-free rate of return. The fair value of property, plant and equipment was determined using both the cost and market approaches which required significant Level 3 inputs. Key assumptions included i) estimated replacement costs for individual assets or asset groups, ii) estimated remaining useful lives for the acquired assets, and iii) recent market transactions for similar assets. The fair value of intangible assets was determined using the income approach which also required significant Level 3 inputs. Key assumptions included i) estimated throughput volumes, ii) forward market prices for natural gas and NGLS as of the acquisition date, iii) estimated future operating and development cash flows, and iv) discount rates ranging from 11.0% to 16.0% . The intangible assets acquired relate to existing customer relationships which Costar had at the time of the acquisition, as well as agreements with two producers under which Costar agreed to construct and operate gathering and processing facilities in exchange for the producers’ agreements to dedicate certain acreage and related production to those facilities. Working capital includes $11.2 million of accounts receivable, all of which were subsequently collected. During 2015, the Partnership reached agreements with the Costar sellers regarding certain matters which resulted in a return of $7.4 million of cash to the Partnership and related reductions in the goodwill initially recorded. Additionally, in February 2016, the Partnership reached a settlement of certain indemnification claims with the Costar sellers whereby 1,034,483 common units held in escrow were returned to the Partnership, while the Partnership agreed to pay the Costar sellers an additional $0.3 million . The net impact of this settlement will be recorded as a reduction in property, plant and equipment in the first quarter of 2016. As described in Note 9 "Goodwill and Intangible Assets, net", the Partnership recognized a $95.0 million impairment of the remaining Costar goodwill during the fourth quarter of 2015. Costar contributed revenue of $19.9 million and operating income of $0.3 million for the period of October 14, 2014 through December 31, 2014, which was attributable to the Partnership's Gathering and Processing segment. Additionally, the Partnership incurred $0.5 million of transaction costs related to the acquisition which are included in Selling, general and administrative expenses in our consolidated statement of operations for the year ended December 31, 2014. The following unaudited pro forma summary presents consolidated financial information for the Partnership as if the Costar acquisition had occurred on January 1, 2013 (in thousands): Years Ended December 31, 2014 2013 Revenue $ 435,133 $ 448,748 Net loss (101,237 ) (30,672 ) Limited partners' net loss per unit (6.15 ) (3.82 ) These pro forma amounts have been calculated after applying the Partnership’s accounting policies to Costar’s historical results and making adjustments to reflect additional interest expense that would have been incurred and additional depreciation and amortization expense that would have been recognized had the acquisition occurred as of January 1, 2013. The unaudited pro forma adjustments are based on available information and certain assumptions we believe are reasonable. Lavaca Acquisition On January 31, 2014, the Partnership acquired approximately 120 miles of high- and low-pressure pipelines and associated facilities located in the Eagle Ford shale in Gonzales and Lavaca Counties, Texas from Penn Virginia Corporation (NYSE: PVA) ("PVA") for $104.4 million in cash (the "Lavaca Acquisition"). The Lavaca Acquisition was financed with proceeds from the Partnership's January 2014 equity offering and from the issuance of Series B Units to our General Partner. The Lavaca Acquisition was accounted for using the acquisitions method of accounting and, as a result, the purchase price was allocated to the assets acquired upon their respective fair values as of the acquisition date. The excess of the purchase price over the fair value of the assets acquired was classified as goodwill. The following table summarizes the final allocation of the purchase price to the assets acquired in the Lavaca Acquisition based upon their respective fair values as of the acquisition date (in thousands): Property, plant and equipment: Land $ 2 Pipelines 58,737 Equipment 753 Total property, plant and equipment 59,492 Intangible assets 21,350 Goodwill 23,567 Total cash consideration $ 104,409 The fair value of property, plant and equipment was determined using the cost approach which required significant Level 3 inputs. Key assumptions included i) estimated replacement costs for individual assets or asset groups and ii) estimated remaining useful lives for the acquired assets. The fair value of intangible assets was determined using the income approach which also required significant Level 3 inputs. Key assumptions included i) estimated throughput volumes, ii) future operating and development cash flows, and iii) a discount rate of 10.5% . The intangible assets acquired relate to a 25 -year gas gathering agreement under which PVA will dedicate certain acreage and related production to the acquired facilities. As described in Note 9 "Goodwill and Intangible Assets, net", the Partnership recognized a $23.6 million impairment of the remaining Lavaca goodwill during the fourth quarter of 2015. Lavaca contributed revenue of $16.8 million and net income of $7.6 million for the period from January 31, 2014 through December 31, 2014, attributable to the Partnership's Gathering and Processing segment. The Partnership incurred $0.1 million of transaction costs related to the acquisition, which are included in Selling, general and administrative expenses in our consolidated statement of operations for the year ended December 31, 2014. Pro forma financial information to show the impact on the Partnership’s financial information as if the Lavaca acquisition had been completed on January 1, 2013, have not been presented as the Partnership was unable to obtain the necessary information from the seller. Other Acquisitions Investment in Unconsolidated Affiliate On August 11, 2014, the Partnership acquired a 66.7% non-operated interest in MPOG, an offshore crude oil gathering system, for a net purchase price of $12.0 million , which was financed with borrowings from the Partnership's credit facility. Although the Partnership owns a majority interest in MPOG, the ownership structure requires unanimous approval of all owners on decisions impacting the operation of the assets and any changes in ownership structure. Therefore, the Partnership's voting rights are not proportional to its obligation to absorb losses or receive returns. The Partnership accounts for its 66.7% interest using the equity method. For the year ended December 31, 2015, the Partnership recorded $0.7 million in earnings from MPOG, and received cash distributions of $3.9 million . For the year ended December 31, 2014, the Partnership recorded $0.3 million in earnings from MPOG, and received cash distributions of $2.0 million . The excess of the cash distributions received over the earnings recorded from MPOG is classified as a return of capital within cash flows from investing activities in our consolidated statements of cash flows. Williams Pipeline Acquisition In the first quarter of 2014, the Partnership acquired natural gas pipeline facilities that are contiguous to and connect with our High Point System in offshore Louisiana from Transcontinental Gas Pipe Line Company, LLC ("Transco"), a subsidiary of Williams Partners, LP for $6.5 million in cash (the "Williams Pipeline Acquisition"). The acquisition was subject to FERC approval of the seller's application to abandon the pipeline facilities to us by sale and to permit the facilities to serve a gathering function, exempt from FERC's jurisdiction. The FERC granted approval of the application during the first quarter of 2014, and the purchase and sale agreement closed on March 14, 2014. The purchase price was allocated to pipelines using the income approach which required certain Level 3 inputs. Blackwater Terminals Acquisition On December 17, 2013, the Partnership acquired Blackwater Midstream Holdings LLC ("Blackwater"), a Delaware limited liability company and other related subsidiaries from an affiliate of HPIP. Blackwater operated 1.3 million barrels of storage capacity across four marine terminal sites located in Westwego, Louisiana; Brunswick, Georgia; Harvey, Louisiana; and Salisbury, Maryland. Because Blackwater was previously owned by an affiliate our General Partner, we have accounted for the acquisition at our General Partner's carry-over basis. The Partnership' total consideration distributed for the acquisition was $63.9 million . The amount by which the total consideration exceeded the carry-over basis was $27.7 million and was recorded as a distribution within the consolidated statements of changes in partners’ capital and noncontrolling interest and as a financing activity in the consolidated statement of cash flows. The consideration also included 125,500 limited partner units which were accounted for as a non-cash distribution to the General Partner at a fair value of $3.1 million . The fair value of the units issued was determined using level one inputs based upon the Partnership's closing unit price on December 17, 2013. The remaining consideration was utilized to settle all of the Blackwater's outstanding debt at December 17, 2013. The acquisition of Blackwater represents a transaction between entities under common control and a change in reporting entity. Transfers of net assets or exchanges of shares between entities under common control are accounted for as if the transfer occurred at the beginning of the period or date of common control. Therefore, net assets received were recorded at their historical book value of $22.7 million as of the date common control was established, which is April 15, 2013. For the period from April 15, 2013 to December 31, 2013, our Blackwater contributed $9.8 million of revenue and $0.8 million of net loss attributable to the Partnership's Terminals segment, which are included in the consolidated statements of operations. High Point System Effective April 15, 2013, an affiliate of our General Partner contributed the High Point System, consisting of 100% of the limited liability company interests in High Point Gas Transmission, LLC, and High Point Gas Gathering, LLC. The High Point System consists of approximately 700 miles of natural gas and liquids pipeline assets located in southeast Louisiana, in the Plaquemines and St. Bernard parishes, and the shallow water and deep shelf Gulf of Mexico, including the Mississippi Canyon, Viosca Knoll, West Delta, Main Pass, South Pass and Breton Sound zones. Natural gas is collected at more than 75 receipt points that connect hundreds of wells with an emphasis on oil and liquids-rich reservoirs. The High Point System, along with $15.0 million in cash, was contributed to us by HPIP in exchange for 5,142,857 Series A Units. Of the cash consideration paid by HPIP, approximately $2.5 million was used to pay certain transaction expenses of HPIP, and the remaining approximately $12.5 million was used to repay borrowings outstanding under the Partnership's former credit facility. The contribution of the High Point System occurred concurrently with HPIP's acquisition of 90% of our General Partner and all of our subordinated units, which resulted in HPIP gaining control of our General Partner and a majority of our outstanding limited partner interests. The fair value of the Series A Units on April 15, 2013, was $17.50 per unit, or a total of $90.0 million , and was issued by the Partnership in exchange for net cash of approximately $12.5 million and net assets of $61.9 million contributed to the Partnership by our General Partner. Because the High Point System was previously owned by our General Partner, we have accounted for this acquisition at our General Partner's final carry-over basis. As such, the amount by which the value of the Series A Units exceeded the carry-over basis of the net assets contributed by our General Partner was $15.6 million and was recorded as a distribution to our General Partner and existing limited partners' interest based on their ownership interests within the consolidated statements of changes in partners’ capital and noncontrolling interest. The fair value measurement was based on significant inputs not observable in the market and thus represents a Level 3 measurement as defined by ASC 820. Primarily using the income approach, the fair value estimate was based on i) present value of estimated future contracted distributions, ii) an assumed discount rate of 18.0% , and iii) an assumed distribution growth rate of 1.0% in 2014 and thereafter. Subsequent to the contribution, for the year ended December 31, 2013, the High Point System contributed $30.4 million of revenue and $7.2 million of net income attributable to the Partnership's Transmission segment, which are included in the consolidated statements of operations. Divestitures On September 14, 2015, the Partnership disposed of certain terminal assets in Salisbury, Maryland, that were previously held for sale, with a book value approximating the sales proceeds of $0.9 million , resulting in a non-cash loss on disposal of less than $0.1 million . Of the proceeds received, the Partnership distributed $0.5 million to our General Partner in accordance with the Agreement and Plan of Merger. On June 1, 2015, the Partnership disposed of certain non-strategic off-shore transmission assets in Louisiana with a net book value of $3.0 million for nominal proceeds, resulting in a non-cash loss on disposal of $3.0 million . On March 31, 2014, the Partnership completed the sale of certain gathering and processing assets in Madison County, Texas, in exchange for $6.1 million in cash which resulted in a nominal gain. The Partnership recognized a $3.0 million impairment charge related to these assets for the year ended December 31, 2013, to reduce the related carrying value of $6.1 million .

Discontinued Operations (Notes)

Discontinued Operations (Notes)	12 Months Ended
	Dec. 31, 2015
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal Groups, Including Discontinued Operations, Disclosure [Text Block]	Discontinued Operations During 2013, the Board of Directors of our General Partner approved a plan to sell certain non-strategic gathering and processing assets which met specific criteria, qualifying them as held for sale. During the year ended December 31, 2013, certain gathering and processing assets were written down by $1.8 million to the estimated fair value less cost to sell. These fair value measurements were based on significant inputs not observable in the market and thus represent a Level 3 measurement as defined by ASC 820. Primarily using the income approach, the fair value estimates were based on i) present value of estimated EBITDA, ii) an assumed discount rate of 10% , and iii) a decline in throughput volumes of 2.5% in 2013 and thereafter. During the second quarter of 2014, the Partnership’s management decided not to sell a portion of the assets that had previously been reclassified to discontinued operations and assets held for sale in the second quarter of 2013. In accordance with ASC 360, the Partnership reclassified the assets as held and used at the carrying value of the assets before they were classified as held for sale, adjusted for depreciation expense that would have been recorded. The Partnership has reclassified the amounts recorded in discontinued operations related to the assets for all prior periods presented. As part of the Blackwater Acquisition, we acquired long-lived terminal assets which were immediately classified as held for sale. As of December 31, 2013, these assets were written down by $0.6 million to the estimated fair value less cost to sell. As a result of deteriorating market conditions, the Partnership recognized an additional impairment charge on these assets of $0.7 million in 2014. These assets were sold during the third quarter of 2015 at a nominal loss. Historically, we have classified these assets as discontinued operations within our consolidated statements of operations. We elected not to separately present the operating, investing and financing cash flows related to the disposal groups in our accompanying consolidated statements of cash flows as this activity was immaterial for all periods presented. The following table presents the revenue, expense and (loss) gain from discontinued operations associated with the assets classified as held for sale for the years ended December 31, 2015 , 2014 , and 2013 (in thousands, except per unit amounts): Years Ended December 31, 2015 2014 2013 Revenue $ 74 $ 474 $ 2,084 Expense (196 ) (658 ) (2,361 ) Impairment — (673 ) (2,400 ) Loss on sale of assets (150 ) (87 ) (75 ) Income tax benefit 192 333 339 Income (loss) from discontinued operations, net of tax $ (80 ) $ (611 ) $ (2,413 ) Limited partners' net income (loss) per unit from discontinued operations (basic and diluted) $ — $ (0.04 ) $ (0.27 )

Concentration of Credit Risk an

Concentration of Credit Risk and Trade Accounts Receivable	12 Months Ended
	Dec. 31, 2015
Receivables [Abstract]
Concentration Risk Disclosure [Text Block]	Concentration of Credit Risk and Trade Accounts Receivable Our primary assets, which are strategically located in Alabama, Georgia, Louisiana, Mississippi, North Dakota, Tennessee, Texas and the Gulf of Mexico, provide critical infrastructure that links customers of natural gas, crude oil, NGLs, condensate and specialty chemicals to numerous intermediate and end-use markets. As a result of recent acquisitions and geographic diversification, we have reduced the concentration of trade receivable balances due from these customer groups, and reduced the concentration which may affect our overall credit risk. Our customers' historical financial and operating information is analyzed prior to extending credit. We manage our exposure to credit risk through credit analysis, credit approvals, credit limits and monitoring procedures, and for certain transactions, we may request letters of credit, prepayments or guarantees. We record allowances for potentially uncollectible accounts receivable when necessary; however, for the years ended December 31, 2015 , 2014 and 2013 , no allowances or significant write-offs of accounts receivable were required. The following table summarizes those customers who accounted for more than 10% of the Partnership's consolidated revenue for the each of the last three years: Years Ended December 31, 2015 2014 2013 Customer A 10 % 22 % 28 % Customer B — % — % 13 % Customer C — % 12 % 12 % Customer D — % 10 % 10 % Other 90 % 56 % 37 % Total 100 % 100 % 100 %

Other Current Assets

Other Current Assets	12 Months Ended
	Dec. 31, 2015
Other Current Assets [Abstract]
Other Current Assets	Other Current Assets Other current assets consists of the following (in thousands): December 31, 2015 2014 Prepaid insurance—current portion $ 3,948 $ 4,162 Restricted cash — 6,475 Other prepaid amounts 2,866 758 Other current assets 3,280 4,159 $ 10,094 $ 15,554 Restricted cash of $6.5 million as of December 31, 2014 consisted of a cash-backed letter of credit related to Costar operations that the Partnership was contractually obligated to maintain after the Costar Acquisition. The Partnership was released from this obligation in January 2015. Other current assets primarily consist of natural gas imbalances and amounts due from related parties.

Derivatives

Derivatives	12 Months Ended
	Dec. 31, 2015
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivatives	Derivatives Commodity Derivatives To minimize the effect of commodity price changes and maintain our cash flow and the economics of our development plans, we enter into commodity hedge contracts from time to time. The terms of the contracts depend on various factors, including management's view of future commodity prices, economics on purchased assets and future financial commitments. This hedging program is designed to mitigate the effect of commodity price declines while allowing us to participate in some commodity price upside. Management regularly monitors the commodity markets and financial commitments to determine if, when, and at what level commodity hedging is appropriate in accordance with policies that are established by the Board of Directors of our General Partner. Due to declining prices, we had not entered into commodity hedge contracts to hedge production in 2016 and beyond as of December 31, 2015. From time to time, we enter into commodity contracts with multiple counterparties, and in some cases, may be required to post collateral with our counterparties in connection with our derivative positions. As of December 31, 2015 , we had not posted collateral with our counterparties. The counterparties are not required to post collateral with us in connection with their derivative positions. Netting agreements are in place that permit us to offset our commodity derivative asset and liability positions with our counterparties. We did not designate any of our commodity derivatives as hedges for accounting purposes. As a result, our commodity derivatives are accounted for at fair value in our consolidated balance sheets with changes in fair value recognized currently in earnings. Interest Rate Swap To manage the impact of the interest rate risk associated with our Credit Agreement we enter into interest rate swaps from time to time, effectively converting a portion of the cash flows related to our long-term variable rate debt into fixed rate cash flows. The notional amount of our interest rate swap that expired on August 1, 2015 was $100.0 million . The interest rate swap was entered into with a single counterparty and we were not required to post collateral. On March 2, 2016, we entered into interest rate swaps with a notional amount of $200.0 million that will expire in September 2019. Weather Derivative In the second quarters of 2015 and 2014, we entered into weather derivatives to mitigate the impact of potential unfavorable weather to our operations under which we could receive payments totaling up to $10.0 million in the event that a hurricane or hurricanes of certain strength pass through the area as identified in the derivative agreement. The weather derivatives are accounted for using the intrinsic value method, under which the fair value of the contract was zero and any amounts received are recognized as gains during the period received. The weather derivatives were entered into with a single counterparty and we were not required to post collateral. We paid premiums of $0.9 million and $1.0 million in 2015 and 2014, respectively, which are recorded as current Risk management assets on the consolidated balance sheets and are amortized to Direct operating expenses on a straight-line basis over the term of the contract of 1 year . Unamortized amounts associated with weather derivatives were approximately $0.4 million and $0.4 million as of December 31, 2015 and 2014, respectively. As of December 31, 2015 and 2014 , the value associated with our commodity derivatives, interest rate swap and weather derivative were recorded in our consolidated balance sheets, under the captions as follows (in thousands): Gross Risk Management Assets Gross Risk Management Liabilities Net Risk Management Assets (Liabilities) Balance Sheet Classification December 31, 2015 December 31, 2014 December 31, 2015 December 31, 2014 December 31, 2015 December 31, 2014 Current $ 365 $ 688 $ — $ — $ 365 $ 688 Noncurrent — — — — — — Total assets $ 365 $ 688 $ — $ — $ 365 $ 688 Current $ — $ — $ — $ (215 ) $ — $ (215 ) Noncurrent — — — — — — Total liabilities $ — $ — $ — $ (215 ) $ — $ (215 ) For the years ended December 31, 2015 , 2014 and 2013 , the realized and unrealized gains (losses) associated with our commodity, interest rate and weather derivative instruments were recorded in our consolidated statements of operations, under the captions as follows (in thousands): Realized Unrealized 2015 Gain (loss) on commodity derivatives, net $ 1,610 $ (286 ) Interest expense (240 ) 215 Direct operating expenses (913 ) — Total $ 457 $ (71 ) 2014 Gain (loss) on commodity derivatives, net $ 735 $ 356 Interest expense (433 ) 239 Direct operating expenses (1,035 ) — Total $ (733 ) $ 595 2013 Gain (loss) on commodity derivatives, net $ 1,069 $ (1,041 ) Interest expense (207 ) (454 ) Direct operating expenses (662 ) — Total $ 200 $ (1,495 )

Fair Value Measurement

Fair Value Measurement	12 Months Ended
	Dec. 31, 2015
Fair Value Disclosures [Abstract]
Fair Value Measurement	Fair Value Measurement We believe the carrying amount of cash and cash equivalents, accounts receivable and accounts payable approximate fair value because of the short-term maturity of these instruments. The recorded value of the amounts outstanding under the Credit Agreement approximates its fair value, as interest rates are variable, based on prevailing market rates and the short-term nature of borrowings and repayments under the Credit Agreement. The fair value of all derivatives instruments is estimated using a market valuation methodology based upon forward commodity price curves, volatility curves as well as other relevant economic measures, if necessary. Discount factors may be utilized to extrapolate a forecast of future cash flows associated with long dated transactions or illiquid market points. The inputs are obtained from independent pricing services, and we have made no adjustments to the obtained prices. We have consistently applied these valuation techniques in all periods presented and believe we have obtained the most accurate information available for the types of derivatives contracts held. We will recognize transfers between levels at the end of the reporting period for which the transfer has occurred. There were no such transfers during 2015, 2014 or 2013. Fair Value of Financial Instruments The following table sets forth by level within the fair value hierarchy, our commodity derivative instruments and interest rate swap, included as part of Risk management assets and Risk management liabilities within the consolidated balance sheets, that were measured at fair value on a recurring basis as of December 31, 2015 and 2014 (in thousands): Carrying Amount Estimated Fair Value of the Asset (Liability) Level 1 Level 2 Level 3 Total Commodity derivative instruments, net December 31, 2015 $ — $ — $ — $ — $ — December 31, 2014 286 — 286 — 286 Interest rate swap December 31, 2015 $ — $ — $ — $ — $ — December 31, 2014 (215 ) — (215 ) — (215 ) The unamortized portion of the premium paid to enter the weather derivative described in Note 6 "Derivatives," is included within Risk management assets on the consolidated balance sheets but is not included in the above table as it is recorded at amortized cost, not fair value.

Property, Plant and Equipment,

Property, Plant and Equipment, Net	12 Months Ended
	Dec. 31, 2015
Property, Plant and Equipment [Abstract]
Property, Plant and Equipment, Net	Property, Plant and Equipment, Net Property, plant and equipment, net, as of December 31, 2015 and 2014 , were as follows (in thousands): Useful Life (in years) December 31, December 31, Land N/A $ 5,282 $ 5,282 Construction in progress N/A 46,045 77,550 Buildings and improvements 4 to 40 9,864 6,855 Processing and treating plants 8 to 40 97,784 80,837 Pipelines and compressors 3 to 40 554,400 476,997 Storage 20 to 40 58,394 38,151 Equipment 5 to 20 22,207 12,345 Total property, plant and equipment 793,976 698,017 Accumulated depreciation (145,963 ) (115,835 ) Property, plant and equipment, net $ 648,013 $ 582,182 Of the gross property, plant and equipment balances at December 31, 2015 and 2014 , $111.9 million and $101.9 million , respectively, related to our FERC regulated interstate and intrastate assets. Capitalized interest was $1.9 million , $0.8 million and $0.2 million for the years ended December 31, 2015 , 2014 and 2013 , respectively. Depreciation expense was $31.9 million , $23.9 million and $25.9 million for the years ended December 31, 2015 , 2014 and 2013 , respectively. 2014 Impairments During the fourth quarter of 2014, management noted the declining commodity markets and related impact on producers and shippers to whom we provide gathering and processing services. The decline in the market price of crude oil led to a corresponding decrease in natural gas and crude oil production impacting the volume of natural gas and NGLs we gather and process on certain assets. As a result, an asset impairment charge of $99.9 million was recorded in the three months ended December 31, 2014. These fair value measurements are based on significant inputs not observable in the market and thus represented a Level 3 measurement as defined by ASC 820. Primarily using the income approach, the fair value estimates were based on i) present value of estimated EBITDA, ii) an assumed discount rate of 9.5% , and iii) the expected remaining useful life of the asset or asset group. See Note 3 "Discontinued Operations" for discussion related to additional impairments. 2013 Impairments During 2013, management changed its commercial approach towards certain non-strategic gathering and processing assets. As a result, an asset impairment charge of $15.2 million was recorded in the three months ended June 30, 2013. These fair value measurements were based on significant inputs not observable in the market and thus represented a Level 3 measurement as defined by ASC 820. Primarily using the income approach, the fair value estimates were based on i) present value of estimated EBITDA, ii) an assumed discount rate of 10% , and iii) a decline in throughput volumes of 2.5% in 2013 and thereafter.

Goodwill and Intangible assets

Goodwill and Intangible assets (Notes)	12 Months Ended
	Dec. 31, 2015
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Intangible Assets Disclosure [Text Block]	Goodwill and Intangible Assets, Net Management performs an annual goodwill assessment at the reporting unit level. This annual goodwill assessment is based on fair value measurements that are based on significant inputs not observable in the market and thus represent a Level 3 measurement as defined by ASC 820. In its assessment, management primarily uses a discounted cash flow analysis, supplemented by a market approach analysis. Key assumptions in the analysis include the use of an appropriate discount rate, volume forecasts, storage utilization, terminal year multiples, and estimated future cash flows including an estimate of operating costs, and maintenance capital expenditures. In estimating cash flows, management incorporates current market information, as well as historical and other factors into the forecasted commodity prices and contracted rates used. Management utilized the fair value approach described above in performing step one of its annual goodwill impairment test during the fourth quarter of 2015. As a result of our step one analysis, we determined that the estimated fair value of certain reporting units within our Gathering and Processing reportable segment were less than their respective carrying amounts, primarily due to changes in assumptions related to commodity prices, timing of estimated drilling by producers, and discount rates. The changes in the assumptions noted were adversely impacted by the continuing decline in market conditions within the energy sector. The second step of the goodwill impairment test involves allocating the estimated fair value of each reporting unit among the assets and liabilities of the reporting unit in a hypothetical purchase price allocation. The results of the hypothetical purchase price allocation indicated there was no fair value attributable to goodwill of the reporting units within our Gathering and Processing reportable segment. As a result, we recognized a Loss on impairment of goodwill of $118.6 million during the fourth quarter of 2015. The impairment consisted of $95.0 million and $23.6 million related to the Costar and Lavaca Acquisitions, respectively. The carrying value of goodwill as of December 31, 2015 and 2014 , was $16.3 million and $142.2 million , respectively. Goodwill as of December 31, 2015 related to our Terminal segment, while $125.9 million and $16.3 million related to our Gathering and Processing and Terminal segment, respectively, as of December 31, 2014 . The goodwill associated with our Terminal segment was obtained primarily as part of the Blackwater Acquisition described in Note 2 "Acquisitions and Divestitures". Intangible assets, net, consists of customer contracts, relationships and dedicated acreage agreements identified as part of the Costar, Lavaca and Blackwater acquisitions. These intangible assets have definite lives and are subject to amortization on a straight-line basis over their economic lives, currently ranging from 10 years to 30 years . Intangible assets, net, consist of the following (in thousands): December 31, 2015 2014 Gross carrying amount: Customer contracts $ 12,101 $ 12,101 Customer relationships 53,400 53,400 Dedicated acreage 53,350 53,350 $ 118,851 $ 118,851 Accumulated amortization: Customer contracts $ (12,101 ) $ (11,110 ) Customer relationships (3,124 ) (553 ) Dedicated acreage (2,661 ) (882 ) $ (17,886 ) $ (12,545 ) Net carrying amount: Customer contracts $ — $ 991 Customer relationships 50,276 52,847 Dedicated acreage 50,689 52,468 $ 100,965 $ 106,306 For the years ended December 31, 2015 , 2014 and 2013 , amortization expense on our intangible assets totaled $5.3 million , $ 4.1 million and $3.7 million , respectively. Estimated amortization expense for each of the next five fiscal years (2016 – 2020) is approximately $ 4.3 million per year.

Investment in unconsolidated af

Investment in unconsolidated affiliates (Notes)	12 Months Ended
	Dec. 31, 2015
Equity Method Investments and Joint Ventures [Abstract]
Equity Method Investments and Joint Ventures Disclosure [Text Block]	10. Investment in Unconsolidated Affiliates The following table presents the activity in the Partnership's equity investments (in thousands): MPOG Mesquite Pinto/Delta House Total 66.7% 46% 12.9% Balances at December 31, 2013 $ — $ — $ — $ — Initial investment 12,000 11,884 — 23,884 Earnings in unconsolidated affiliates 348 — — 348 Distributions (1,980 ) — — (1,980 ) Balances at December 31, 2014 $ 10,368 $ 11,884 $ — $ 22,252 Initial investment — — 65,703 65,703 Earnings in unconsolidated affiliates 731 — 7,470 8,201 Contributions — 6,713 — 6,713 Distributions (3,920 ) — (16,648 ) (20,568 ) Balances at December 31, 2015 $ 7,179 $ 18,597 $ 56,525 $ 82,301 The following tables present the summarized combined financial information for the Partnership's equity investments (amounts represent 100% of investee financial information): Years Ended December 31, Balance Sheets: 2015 2014 Current assets $ 2,086 $ 2,196 Non-current assets 288,617 62,635 Current liabilities 366 398 Non-current liabilities 23,617 22,307 Years Ended December 31, Income Statements: 2015 2014 2013 Total revenue $ 37,724 $ 3,847 $ — Operating expense 3,375 1,722 — Net income 29,437 510 — The unconsolidated affiliates described above were each determined to be Variable Interest Entities ("VIE") due to disproportionate economic interests and decision making rights. In each case, the Partnership lacks the power to direct the activities that most significantly impact each unconsolidated affiliate's economic performance. As the Partnership does not hold a controlling financial interest in these affiliates, the Partnership accounts for its related investments using the equity method. The Partnership’s maximum exposure to loss related to each VIE is limited to its equity investment as presented on the consolidated balance sheet at December 31, 2015. In each case, the Partnership is not obligated to absorb losses greater than its proportional ownership percentages indicated above. In each case, the Partnership’s right to receive residual returns is not limited to any amount less than the proportional ownership percentages indicated above.

Accrued Expenses and Other Curr

Accrued Expenses and Other Current Liabilities	12 Months Ended
	Dec. 31, 2015
Payables and Accruals [Abstract]
Accounts Expenses and Other Current Liabilities	Accrued Expenses and Other Current Liabilities Accrued expenses and other current liabilities were as follows (in thousands): December 31, 2015 2014 Current portion of asset retirement obligation $ 6,822 $ — Accrued capital expenditures 3,984 17,134 Accrued expenses 3,178 4,560 Due to related parties 3,894 659 Gas imbalances payable 413 1,055 Other 6,744 2,392 $ 25,035 $ 25,800

Asset Retirement Obligation

Asset Retirement Obligation	12 Months Ended
	Dec. 31, 2015
Asset Retirement Obligation Disclosure [Abstract]
Asset Retirement Obligation	Asset Retirement Obligations The following table presents activity in the Partnership's asset retirement obligations (in thousands): Years Ended December 31, 2015 2014 Beginning asset retirement obligation $ 34,645 $ 34,636 Liabilities assumed — 248 Expenditures (91 ) (1,030 ) Accretion expense 817 791 Total ending asset retirement obligation 35,371 34,645 Less: current portion 6,822 — Long-term asset retirement obligation $ 28,549 $ 34,645 We are required to establish security against any potential secondary obligations relating to the abandonment of certain transmission assets that may be imposed on the previous owner by applicable regulatory authorities. As such, we have a restricted cash account maintained by a third party that amounted to $5.0 million as of December 31, 2015 and 2014 , respectively, and is presented in Other assets, net in our consolidated balance sheets.

Debt Obligations

Debt Obligations	12 Months Ended
	Dec. 31, 2015
Debt Disclosure [Abstract]
Debt Obligations	Our outstanding borrowings under the credit facility were (in thousands): December 31, 2015 2014 Revolving credit facility $ 525,100 $ 372,950 Other debt 2,338 2,908 Total debt 527,438 375,858 Less: current portion 2,338 2,908 Long-term debt $ 525,100 $ 372,950 On September 14, 2014, the Partnership entered into the Amended and Restated Credit Agreement, which was amended by the First Amendment and Incremental Commitment Agreement dated as of September 18, 2015 (as amended, the "Credit Agreement"), which provides for maximum borrowings equal to $750.0 million , with the ability to further increase the borrowing capacity to $900.0 million subject to lender approval. We can elect to have loans under our Credit Agreement bear interest either at a Eurodollar-based rate, plus a margin ranging from 2.00% to 3.25% depending on our total leverage ratio then in effect, or a base rate which is a fluctuating rate per annum equal to the highest of (a) the Federal Funds Rate plus 0.50% , (b) the rate of interest in effect for such day as publicly announced from time to time by Bank of America as its "prime rate," or (c) the Eurodollar Rate plus 1.00% plus a margin ranging from 1.00% to 2.25% depending on the total leverage ratio then in effect. We also pay a commitment fee of 0.50% per annum on the undrawn portion of the revolving loan under the Credit Agreement. Our obligations under the Credit Agreement are secured by a lien on substantially all of our assets. Advances made under the Credit Agreement are guaranteed on a senior unsecured basis by certain of our subsidiaries (the “Guarantors”). These guarantees are full and unconditional and joint and several among the Guarantors. The terms of the Credit Agreement include covenants that restrict our ability to make cash distributions and acquisitions in some circumstances. The remaining principal balance of loans and any accrued and unpaid interest will be due and payable in full on the maturity date, which is September 5, 2019. The Credit Agreement contains certain financial covenants, including the requirement that our indebtedness not exceed 4.75 times adjusted consolidated EBITDA for the prior twelve month period adjusted in accordance with the Credit Agreement (except for the current and subsequent two quarters after the consummation of a permitted acquisition, at which time the covenant is increased to 5.25 times adjusted consolidated EBITDA) and a minimum interest coverage ratio test that requires our adjusted consolidated EBITDA to exceed consolidated interest charges by not less than 2.50 times. The financial covenants in our Credit Agreement may limit the amount available to us for borrowing to less than $750.0 million . In addition to the financial covenants described above, the Credit Agreement also contains customary representations and warranties (including those relating to organization and authorization, compliance with laws, absence of defaults, material agreements and litigation) and customary events of default (including those relating to monetary defaults, covenant defaults, cross defaults and bankruptcy events). For the years ended December 31, 2015 , 2014 and 2013 , the weighted average interest rate on borrowings under our Credit Agreement was approximately 3.67% , 3.80% , and 4.53% , respectively. As of December 31, 2015 , our consolidated total leverage was 4.56 and our interest coverage ratio was 8.56 , which was in compliance with the consolidated total leverage ratio and interest coverage ratio tests in accordance with the financial covenants required in our Credit Agreement. At December 31, 2015 and 2014 , letters of credit outstanding under the Credit Agreement were $1.8 million and $1.6 million , respectively. As of December 31, 2015 , we had approximately $525.1 million of outstanding borrowings under our $750.0 million Credit Agreement. As of December 31, 2015, we were in compliance with the covenants included in the Credit Agreement. Our ability to maintain compliance with the leverage and interest coverage ratios included in the Credit Agreement may be subject to, among other things, the timing and success of initiatives we are pursuing, which may include expansion capital projects, acquisitions, or drop down transactions, as well as the associated financing for such initiatives. If required, ArcLight Capital Partners, which controls the General Partner of the Partnership, has agreed to provide financial support for the Partnership to maintain compliance with the covenants contained in the Credit Agreement through December 31, 2016. Other debt As of December 31, 2015 , other debt represents insurance premium financing in the original amount of $3.0 million bearing interest at 3.95% per annum, which is repayable in equal monthly installments of approximately $0.3 million through the third quarter of 2016.

Partners' Capital

Partners' Capital	12 Months Ended
	Dec. 31, 2015
Equity [Abstract]
Partners' Capital	Partners' Capital and Convertible Preferred Units Our capital accounts are comprised of approximately 1.3% general partner interest and 98.7% limited partner interests as of December 31, 2015 . Our limited partners have limited rights of ownership as provided for under our Partnership Agreement and the right to participate in our distributions. Our General Partner manages our operations and participates in our distributions, including certain incentive distributions pursuant to the incentive distribution rights that are non-voting limited partner interests held by our General Partner. Pursuant to our Partnership Agreement, our General Partner participates in losses and distributions based on its interest. The General Partner's participation in the allocation of losses and distributions are not limited and therefore, such participation can result in a deficit to its respective capital account. As such, allocation of losses and distributions for previous transactions between entities under common control have resulted in a deficit to the General Partner's capital account included in our consolidated balance sheets. Prior to the conversion of the Series B Units into common units on February 1, 2016, our General Partner held and participated in the distribution on Series B Units with such distributions being made in cash or with paid-in-kind Series B Units at the election of the Partnership. The holders of Series B Units were entitled to vote along with the holders of Limited Partner common units prior to conversion. HPIP holds and participates on the distributions of Series A-1 Units with such distributions being made in paid-in-kind Series A-1 Units, cash or a combination thereof, at the election of the Board of Directors of our General Partner through the distribution for the earlier of (a) the quarter ended March 31, 2016 or (b) the time in which the Series A-1 Units are converted into common units. The Series A-1 Units are entitled to vote along with Limited Partner common unitholders and such units are currently convertible to Limited Partner common units. Series A-1 Convertible Preferred Units On April 15, 2013, the Partnership, our General Partner and AIM Midstream Holdings entered into agreements with HPIP, pursuant to which HPIP i) acquired 90% of our General Partner and all of our subordinated units from AIM Midstream Holdings and ii) contributed the High Point System and $15.0 million in cash to us in exchange for 5,142,857 Series A-1 Units issued by the Partnership as described in Note 2 "Acquisitions and Divestitures". Of the cash consideration paid by HPIP, approximately $2.5 million was used to pay certain transaction expenses of HPIP, and the remaining approximately $12.5 million was used to repay borrowings outstanding under the Partnership's former credit facility. As a result of these transactions, which were also consummated on April 15, 2013, HPIP acquired both control of our General Partner and a majority of our outstanding limited partnership interests. On April 15, 2013, our General Partner entered into the Third Amended & Restated Agreement of Limited Partnership (the "Third Amendment") of the Partnership providing for the creation and designation of the rights, preferences, terms and conditions of the Series A-1 Units. The Series A-1 Units receive distributions prior to distributions to Partnership common unitholders. The distributions to the Series A-1 Unitholders are equal to the greater of $0.50 per unit or the declared distribution to common unitholders. The Series A-1 Units may be converted into common units on a one-to-one basis, subject to customary anti-dilutive adjustments, at the option of the unitholders on or any time after January 1, 2014. As a result of the equity offering that closed on September 15, 2015, discussed below, the conversion price of the Series A Units were adjusted from $17.50 to $15.94 in accordance with the terms of the Partnership Agreement so that the holders of those units would maintain their ownership interest on an as-converted basis. Upon any liquidation and winding up of the Partnership or the sale of substantially all of the assets of the Partnership, the holders of Series A-1 Units generally will be entitled to receive, in preference to the holders of any of the Partnership's other securities, an amount equal to the sum of $15.94 multiplied by the number of Series A-1 Units owned by such holders, plus all accrued but unpaid distributions on such Series A Units. Prior to the consummation of any recapitalization, reorganization, consolidation, merger, spin-off or other business combination in which the holders of common units are to receive securities, cash or other assets (a "Partnership Event"), we are obligated to make an irrevocable written offer, subject to consummation of the Partnership Event, to each holder of Series A Units to redeem all (but not less than all) of such holder's Series A Units for a price per Series A Unit payable in cash equal to the greater of: • the sum of $15.94 and all accrued and accumulated but unpaid distributions for each Series A-1 Unit; or • an amount equal to the product of: i) the number of common units into which each Series A-1 Unit is convertible; and ii) the sum of: (A) the cash consideration per common unit to be paid to the holders of common units pursuant to the Partnership Event, plus (B) the fair market value per common unit of the securities or other assets to be distributed to the holders of the common units pursuant to the Partnership Event. Upon receipt of such a redemption offer from us, each holder of Series A-1 Units may elect to receive such cash amount or a preferred security issued by the person surviving or resulting from such Partnership Event and containing provisions substantially equivalent to the provisions set forth in the Third Amendment with respect to the Series A-1 Units without material abridgement. Except as provided in the Third Amendment, the Series A-1 Units have voting rights that are identical to the voting rights of the common units and will vote with the common units as a single class, with each Series A-1 Unit entitled to one vote for each common unit into which such Series A-1 Unit is convertible. As conversion is at the option of the holder and redemption is contingent upon a future event which is outside the control of the Partnership, the Series A-1 Units have been classified as mezzanine equity in the consolidated balance sheets. The Partnership executed the Fourth Amendment (the "Fourth Amendment") to the Partnership Agreement related to its outstanding Series A-1 Units which became effective July 24, 2014. As a result of the Fourth Amendment, distributions on Series A-1 Units will be made with paid-in-kind Series A-1 Units, cash or a combination thereof, at the discretion of the Board of Directors, which began with the distribution for the three months ended June 30, 2014 and will continue through the distribution for the quarter ended March 31, 2016. Prior to the Fourth Amendment, the Partnership was required to pay distributions on the Series A-1 Units with a combination of paid-in-kind units and cash. Series A-2 Convertible Preferred Units On March 30, 2015 and June 30, 2015, we entered into two Series A-2 Convertible Preferred Unit Purchase Agreements with Magnolia Infrastructure Partners, LLC (an affiliate of HPIP) pursuant to which the Partnership issued, in separate private placements, newly-designated Series A-2 Units (the “Series A-2 Units”) representing limited partnership interests in the Partnership. As a result, the Partnership issued a total of 2,571,430 Series A-2 Units for approximately $45.0 million in aggregate proceeds during the year ended December 31, 2015. The Series A-2 Units will participate in distributions of the Partnership along with common units in a manner identical to the existing Series A-1 Units (together with the Series A-2 Units, the "Series A Units"), with such distributions being made in cash or with paid-in-kind Series A Units at the election of the Board of Directors of our General Partner. To date, the Board of Directors of our General Partner has elected to pay Series A distributions using paid-in-kind Series A Units. On July 27, 2015, we entered into the Fifth Amendment (the “Fifth Amendment”) to our Partnership Agreement. The Fifth Amendment grants us the right (the “Call Right”) to require the holders of the Series A-2 Units (the “Series A-2 Holders”) to sell, assign and transfer all or a portion of the then outstanding Series A-2 Units to us for a purchase price of $17.50 per Series A-2 Unit (subject to appropriate adjustment for any equity distribution, subdivision or combination of equity interests in the Partnership). We may exercise the Call Right at any time, in connection with our or our affiliate’s acquisition of assets or equity from ArcLightEnergy Partners Fund V, L.P., or one of its affiliates, for a purchase price in excess of $100 million . We may not exercise the Call Right with respect to any Series A-2 Units that a Series A-2 Holder has elected to convert into common units on or prior to the date we have provided notice of our intent to exercise the Call Right, and may not exercise the Call Right if doing so would result in a default under any of our or our affiliates’ financing agreements or obligations. As a result of the equity offering that closed on September 15, 2015, discussed below, the conversion price of the Series A Units was adjusted to $15.94 in accordance with the terms of the Partnership Agreement so that the holders of those units would maintain their ownership interest on an as-converted basis. Series B Units Effective January 31, 2014, the Partnership created and issued 1,168,225 Series B Units to its General Partner in exchange for approximately $30.0 million . The Series B Units participate in distributions of the Board of Directors of our General Partner along with common units, with such distributions being made in cash distributions or with paid-in-kind Series B Units at the election of the Partnership. The Series B Units are entitled to vote along with common unitholders and such units will automatically convert to common units two years after the issuance date. Proceeds from the issuance of the Series B Units were used to partially fund the Lavaca Acquisition. During 2014, the Board of Directors of our General Partner elected to pay the Series B distributions using paid-in-kind Series B Units. The number of paid-in-kind Series B Units is determined by the quotient of: i) the number of Series B Units outstanding at the record date multiplied by the distribution amount declared to common unit holders ("Series B Unit Distribution Amount"), and ii) the Series B Unit Distribution Amount divided by the original issue price of the Series B Units. The Partnership records the paid-in-kind Series B Units at fair value at the time of issuance. The fair value measurement uses our unit price as a significant input in the determination of the fair value and thus represents a Level 2 measurement as defined by ASC 820. For the year ended December 31, 2015 , the Partnership issued 94,923 of paid-in-kind Series B Units with a fair value of $1.4 million . For the year ended December 31, 2014 , the Partnership issued 86,461 of paid-in-kind Series B Units with a fair value of $2.2 million . The Series B Units automatically converted to common units on February 1, 2016. Equity Restructuring Effective August 9, 2013, we executed an equity restructuring agreement ("Equity Restructuring") with our General Partner and HPIP. As part of the Equity Restructuring, the Partnership's 4,526,066 subordinated units and previous incentive distribution rights (the "former IDRs," all of which were owned by our General Partner, which is controlled by HPIP) were combined into and restructured as a new class of incentive distribution rights (the "new IDRs"). Upon the issuance of the new IDRs, the subordinated units and former IDRs were canceled. The new IDRs were allocated 85.02% to HPIP and 14.98% to our General Partner. The new IDRs entitle the holders of our incentive distribution rights to receive 48% of any quarterly cash distributions from available cash after the Partnership's common unitholders have received the full minimum quarterly distribution ( $0.4125 per unit) for each quarter plus any arrearages from prior quarters. On February 5, 2014, further amendments were made as a result of a settlement such that: • HPIP and AIM Midstream Holdings amended the LLC Agreement to, among other things, amend the Sharing Percentages (as defined therein) such that HPIP's sharing percentage thereafter is 95% and AIM Midstream Holdings's Sharing Percentage is 5% ; • HPIP transferred all of the 85.02% of our outstanding new IDRs held by HPIP to our General Partner such that our General Partner owns 100% of the outstanding new IDRs; and • we issued to AIM Midstream Holdings a warrant to purchase up to 300,000 common units of the Partnership at an exercise price of $0.01 per common unit (the "Warrant"), which Warrant, among other terms, i) is exercisable at any time on or after February 8, 2014 until the tenth anniversary of February 5, 2014, ii) contains cashless exercise provisions and iii) contains customary anti-dilution and other protections. The Warrant was exercised on February 21, 2014. Equity Offerings On October 13, 2015, the Partnership and certain of its affiliates entered into an ATM Equity Offering Sales Agreement (the “Sales Agreement”) with Merrill Lynch, Pierce, Fenner & Smith Incorporated and SunTrust Robinson Humphrey, Inc (each, a "Sales Agent"). Pursuant to the Sales Agreement, the Partnership may issue and sell from time to time, through the Sales Agents, common units having an aggregate offering price of up to $100,000,000 . On September 10, 2015, the Partnership and certain of its affiliates entered into an underwriting agreement with Merrill Lynch, Pierce, Fenner & Smith Incorporated, as representative for the underwriters named therein, providing for the issuance and sale by the Partnership of 7,500,000 common units at a price to the public of $11.31 per common unit. The offering closed on September 15, 2015 and the Partnership used the net proceeds of approximately $81.0 million to fund a portion of the Delta House Investment. In connection with this offering, we completed the issuance of an additional 151,937 common units at a price of $11.31 per unit pursuant to the partial exercise of the underwriters' overallotment option on October 8, 2015 for net proceeds of approximately $1.7 million . On October 14, 2014, the Partnership acquired Costar from Energy Spectrum Partners VI LP and Costar Midstream Energy, LLC which was funded, in part, with 6,900,000 of common units issued directly to Energy Spectrum and Costar Midstream Energy LLC, which are subject to customary lock-up provisions. In February 2016, the Partnership reached a settlement of certain indemnification claims with the Costar sellers whereby approximately 1,034,483 common units held in escrow were returned to the Partnership. On July 14, 2014, the Partnership entered into a common unit purchase agreement with certain institutional investors, which was subsequently amended on August 15, 2014, to provide for the sale of 4,622,352 common units representing limited partner interests in the Partnership in a private placement at a price of $25.8075 per common unit (reflecting an adjustment for the Partnership's second quarter distribution of $0.4625 per unit), for cash consideration of $119.3 million . On January 29, 2014, the Partnership and certain of its affiliates entered into an underwriting agreement (the "Underwriting Agreement") with Barclays Capital Inc. and UBS Securities LLC (the "Underwriters"), providing for the issuance and sale by the Partnership, and the purchase by the Underwriters, of 3,400,000 common units representing limited partner interests in the Partnership at a price to the public of $26.75 per common unit. The Partnership used the net proceeds of $86.9 million to fund a portion of the Lavaca Acquisition. On December 11, 2013, the Partnership and certain of its affiliates entered into an underwriting agreement (the "Underwriting Agreement") with Barclays Capital Inc. (the "Underwriter"), providing for the issuance and sale by the Partnership, and the purchase by the Underwriter, of 2,568,712 common units representing limited partner interests in the Partnership at a price to the public of $22.47 per common unit. The Partnership used the net proceeds of $54.9 million to fund a portion of the purchase price for the Blackwater Acquisition. General Partner Units In connection with the equity offerings discussed above and to maintain its ownership percentage, we received proceeds of $1.9 million from our General Partner as consideration for the issuance of 143,517 additional notional general partner units for the year ended December 31, 2015 and proceeds of $5.7 million for the issuance of 206,810 additional notional general partner units for the year ended December 31, 2014 . There were no such contributions in 2013. Outstanding Units The numbers of units outstanding were as follows (in thousands): December 31, 2015 2014 2013 Series A convertible preferred units 9,210 5,745 5,279 Series B convertible units 1,350 1,255 — Limited Partner common units 30,427 22,670 7,414 General Partner units 536 392 185 Distributions We made cash distributions as follows (in thousands): Years Ended December 31, 2015 2014 2013 Series A convertible preferred units $ — $ 2,658 $ 2,375 Limited Partner common units 46,597 22,656 8,207 Limited Partner subordinated units — — 5,073 General Partner units 1,187 333 284 General Partners' incentive distribution rights 5,602 2,362 181 $ 53,386 $ 28,009 $ 16,120 On January 25, 2016, we announced that the Board of Directors of our General Partner declared a quarterly cash distribution of $0.4725 per unit for the fourth quarter ended December 31, 2015, or $1.89 per unit on an annualized basis. The cash distribution was paid on February 12, 2016, to unitholders of record as of the close of business on February 3, 2016. At December 31, 2015 , we had accrued $4.4 million for the paid-in-kind Series A Units that were issued in February 2016 . The fair value of the paid-in-kind Series A Unit distributions for all years presented was determined primarily using the market and income approach utilizing significant inputs not observable in the market and thus represent a Level 3 measurement as defined by ASC 820. Primarily using the income approach the fair value estimates for all three years presented were based on i) present value of estimated future contracted distributions, ii) option values ranging from $0.07 per unit to $9.68 per unit using a Black-Scholes model, iii) assumed discount rates of 10.0% , and iv) assumed distribution growth rates of 1.0% . For the year ended December 31, 2015 , the Partnership issued 893,830 of paid-in-kind Series A Units and recorded accrued and paid-in-kind unitholder distributions for Series A Units with a fair value of $17.0 million . For the year ended December 31, 2014 , the Partnership issued 466,638 of paid-in-kind Series A Units and recorded accrued and paid-in-kind unitholder distributions for Series A Units with a fair value of $13.2 million . For the year ended December 31, 2013 , the Partnership issued 135,705 of paid-in-kind Series A Units and recorded accrued and paid-in-kind unitholder distributions for Series A Units with a fair value of $4.8 million .

Earnings per Unit

Earnings per Unit	12 Months Ended
	Dec. 31, 2015
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Net Income Loss Per Limited and General Partner Unit [Text Block]	Net Income (Loss) per Limited Partner Unit Net income (loss) is allocated to the General Partner and the limited partners in accordance with their respective ownership percentages, after giving effect to distributions on Series A Units, declared distributions on the Series B Units, limited partner and to the General Partner units, including IDRs. Unvested unit-based payment awards that contain non-forfeitable rights to distributions (whether paid or unpaid) are classified as participating securities and are included in our computation of basic and diluted net income per limited partner unit. Basic and diluted net income (loss) per limited partner unit is calculated by dividing limited partners' interest in net income (loss) by the weighted average number of outstanding limited partner units during the period. We determined basic and diluted net income (loss) per limited partner unit as follows, (in thousands, except per unit amounts): Years Ended December 31, 2015 2014 2013 Net income (loss) from continuing operations $ (127,375 ) $ (97,195 ) $ (30,993 ) Net income (loss) attributable to noncontrolling interests 25 214 633 Net income (loss) from continuing operations attributable to the Partnership (127,400 ) (97,409 ) (31,626 ) Less: Distributions on Series A preferred units 16,978 14,492 24,117 Declared distributions on Series B Units 1,373 2,220 — General partner's distributions 6,790 2,694 464 General partner's share in undistributed loss (2,569 ) (1,820 ) (1,708 ) Blackwater net loss from continuing operations — — (716 ) Net income (loss) from continuing operations available to limited Partners (149,972 ) (114,995 ) (53,783 ) Net income (loss) from discontinued operations available to Limited Partners (80 ) (603 ) (2,051 ) Net income (loss) available to Limited Partners $ (150,052 ) $ (115,598 ) $ (55,834 ) Weighted average number of units used in computation of Limited Partners' net income (loss) per unit (basic and diluted) 24,983 13,472 7,525 Limited Partners' net income (loss) from continuing operations per unit (basic and diluted) $ (6.00 ) $ (8.54 ) $ (7.15 ) Limited Partners' net income (loss) from discontinued operations per unit (basic and diluted) — (0.04 ) (0.27 ) Limited Partners' net income (loss) per unit (basic and diluted) $ (6.00 ) $ (8.58 ) $ (7.42 )

Long-Term Incentive Plan

Long-Term Incentive Plan	12 Months Ended
	Dec. 31, 2015
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Long-Term Incentive Plan	Long-Term Incentive Plan Our General Partner manages our operations and activities and employs the personnel who provide support to our operations. On November 2, 2009, the Board of Directors of our General Partner adopted a long-term incentive plan for its employees, consultants and directors who perform services for it or its affiliates. On May 25, 2010, the Board of Directors of our General Partner adopted an Amended and Restated Long-Term Incentive Plan. On July 11, 2012, the Board of Directors of our General Partner adopted a Second Amended and Restated Long-Term Incentive Plan that effectively increased available awards by 871,750 units. On November 19, 2015, the Board of Directors of our General Partner approved the Third Amended and Restated Long-Term Incentive Plan, which, subject to unitholder approval, would increase the number of common units authorized for issuance by 6,000,000 common units. On February 11, 2016, the unitholders approved the Third Amended and Restated Long-Term Incentive Plan to increase the number of available awards by 6,000,000 common units. At December 31, 2015 , 2014 and 2013 , there were 15,484 , 688,976 and 855,089 common units, respectively, available for future grant under the LTIP. All such equity-based awards issued under the LTIP consist of phantom units, DERs or Option Grants. DERs and options have been granted on a limited basis. Future awards, such as options and DERs, may be granted at the discretion of the Compensation Committee and subject to the Board of Directors of our General Partner. Phantom Unit Awards. Ownership in the awards is subject to forfeiture until the vesting date. The LTIP is administered by the Compensation Committee of the Board of Directors of our General Partner, which at its discretion, may elect to settle such vested phantom units with a number of units equivalent to the fair market value at the date of vesting in lieu of cash. Although our General Partner has the option to settle in cash upon the vesting of phantom units, our General Partner has not historically settled these awards in cash. Under the LTIP, grants issued typically vest in increments of 25% on each grant anniversary date and do not contain any vesting requirements other than continued employment. In December 2015, the Board of Directors of our General Partner approved a grant of 200,000 phantom units under the LTIP which contains distribution equivalent rights based on the extent to which the Partnership’s Series A Preferred Unitholders receive distributions in cash and will vest in one lump sum installment on the three year anniversary of the date of grant, subject to acceleration in certain circumstances. The following table summarizes our phantom unit-based awards, in units: Years Ended December 31, Units Weighted-Average Exercise Price Outstanding at beginning of period 201,132 $ 19.85 Granted 546,329 12.25 Forfeited (31,298 ) 15.62 Vested (146,404 ) 18.47 Outstanding at end of period 569,759 $ 13.15 The fair value of our phantom units, which are subject to equity classification, is based on the fair value of our units at the grant date. Compensation costs related to these phantom awards for the years ended December 31, 2015 , 2014 , and 2013 was $3.8 million , $1.5 million and $2.1 million , respectively, and are classified as Equity compensation expense in our consolidated statements of operations and the equity compensation expense in partners' capital on our consolidated balance sheets. The total fair value of vesting units at the time of vesting was $2.6 million , $1.4 million , and $2.2 million for the years ended December 31, 2015 , 2014 , and 2013 , respectively. The total compensation cost related to unvested phantom awards not yet recognized at December 31, 2015 , 2014 , and 2013 was $5.9 million , $3.1 million , and $0.9 million , respectively, and the weighted average period over which this cost is expected to be recognized as of December 31, 2015 , is approximately 2.75 years years. Performance and Service Condition Awards. In November 2015, the Board of Directors of our General Partner modified awards that introduced certain performance and service conditions that are probable, amounting to $2.0 million payable in a variable amount of phantom units awards at the time of grant. As such, these awards are accounted for as liability-based awards and equity-based compensation is to be accrued from the service-inception date through the estimated date of meeting both the performance and service conditions. Compensation costs related to these awards for the years ended December 31, 2015 was $0.5 million . Compensation cost related to unvested awards not yet recognized at December 31, 2015 was $1.5 million . Option to Purchase Common Units. In December 2015, the Board of Directors of our General Partner approved the grant of an option to purchase 200,000 common units of the Partnership at an exercise price per unit equal to $7.50 (the “Option Grant”). The Option Grant will vest in one lump sum installment on January 1, 2019, subject to acceleration in certain circumstances, and will expire on March 15th of the calendar year following the calendar year in which it vests. The fair value of each unit-based option award is estimated on the date of grant using a Black-Scholes pricing model that incorporates the assumptions noted in the following table. Weighted average volatility 47.0 % Expected dividend yield 26.3 % Weighted average expected term (in years) 3.5 Weighted average risk-free rate 1.3 % Estimated expected volatilities were based upon historical volatility of our common units. The expected dividend yield was based on an annualized distribution divided by the closing unit price on the date of grant. The expected term was based on the midpoint between the date of vest and the date of expiration. The risk-free rate was based on the U.S. Treasury yield curve in effect on the date of grant. Compensation costs related to these awards for the years ended December 31, 2015 was immaterial. Compensation cost related to unvested awards not yet recognized at December 31, 2015 was $0.1 million . The following table summarizes our Option Grant awards, in units: Year Ended December 31, 2015 Units Weighted-Average Exercise Price Outstanding at beginning of period — $ — Granted 200,000 7.50 Forfeited — — Vested — — Outstanding at end of period 200,000 $ 7.50

Post-Employment Benefits

Post-Employment Benefits	12 Months Ended
	Dec. 31, 2015
Compensation and Retirement Disclosure [Abstract]
Post-Employment Benefits	Postretirement Benefits One of the Partnership’s subsidiaries has a contributory postretirement benefit plan that provides medical, dental and life insurance benefits for qualified retirees. Plan obligations totaled $0.6 million and $0.7 million at December 31, 2015 and 2014 , respectively, while plan assets totaled $1.8 million and $1.7 million as of those dates. Plan assets are invested primarily in fixed income securities. Net periodic benefit plan costs, which are included in Direct operating expenses in our consolidated statements of operations, are less than $(0.1) million for the years ended December 31, 2015 , 2014 and 2013 . The Partnership expects that annual benefit payments will be made from plan assets in the future and will be less than $0.1 million per year.

Income Tax (Notes)

Income Tax (Notes)	12 Months Ended
	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Income Tax Disclosure [Text Block]	Income Taxes With the exception of certain subsidiaries in our Terminals Segment, the Partnership is not subject to U.S. federal or state income taxes as such income taxes are generally borne by our unitholders through the allocation of our taxable income (loss) to them. The State of Texas does impose a franchise tax that is assessed on the portion of our taxable margin which is apportioned to Texas. Our income tax (expense) benefit for the years ended December 31, 2015, 2014 and 2013 is as follows: Years Ended December 31, 2015 2014 2013 Current income tax benefit (expense) $ — $ (10 ) $ — Deferred income tax benefit (expense) (1,134 ) (547 ) 495 Effective income tax rate 0.9 % 0.6 % 1.6 % A reconciliation of our expected income tax (expense) benefit calculated at the U.S. federal statutory rate of 34% to our actual tax (expense) for the years ended December 31, 2015, 2014 and 2013 is as follows: Years Ended December 31, 2015 2014 2013 Net loss before income tax benefit (expense) $ (126,241 ) $ (96,638 ) $ (31,488 ) US Federal statutory tax rate 34 % 34 % 34 % Federal income tax benefit at statutory rate 42,922 32,857 10,706 Reconciling items: Partnership loss not subject to income tax (43,812 ) (33,216 ) (10,296 ) Income not subject to corporate-level tax — — 222 State and local tax benefit (expense) (103 ) (159 ) 71 Other (141 ) (39 ) (208 ) Income tax benefit (expense) $ (1,134 ) $ (557 ) $ 495 The Partnership’s deferred tax assets and liabilities as of December 31, 2015 and 2014 are summarized below: December 31, 2015 2014 Deferred tax assets: Net operating loss carryforwards $ 7,570 $ 4,173 Other 493 213 Total deferred tax assets 8,063 4,386 Deferred tax liabilities: Property, plant and equipment 13,889 9,112 Intangible assets — 387 Total deferred tax liabilities 13,889 9,499 Deferred income tax liability, net $ (5,826 ) $ (5,113 ) As of December 31, 2015 , certain subsidiaries in our Terminals Segment had net operating losses for federal income tax purposes of approximately $19.3 million which begin to expire in 2028. The annual utilization of the federal net operating losses may be limited by changes in control of the subsidiaries which occurred in 2012 and 2013. We recognize the tax benefits from uncertain tax positions if it is more likely than not that the position will be sustained on examination by the taxing authorities. As of December 31, 2015, we have not recognized tax benefits from uncertain tax positions. The preparation of our income tax returns requires the use of management's estimates and interpretations which may be subjected to review by the respective taxing authorities and may result in an assessment of additional taxes, penalties and interest. Tax years subsequent to 2009 remain subject to examination by federal and state taxing authorities.

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2015
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Legal proceedings We are not currently party to any pending litigation or governmental proceedings, other than ordinary routine litigation incidental to our business. While the ultimate impact of any proceedings cannot be predicted with certainly, our management believes that the resolution of any of our pending proceeds will not have a material adverse effect on our financial condition or results of operations. Environmental matters We are subject to federal and state laws and regulations relating to the protection of the environment. Environmental risk is inherent to natural gas pipeline, NGL and crude pipelines and operations, as well as terminal operations and we could, at times, be subject to environmental cleanup and enforcement actions. We attempt to manage this environmental risk through appropriate environmental policies and practices to minimize any impact our operations may have on the environment. Regulatory matters On October 8, 2014, American Midstream (Midla), LLC ("Midla") reached an agreement in principle with its customers regarding the interstate pipeline that traverses Louisiana and Mississippi in order to provide continued service to its customers while addressing safety concerns with the existing pipeline. On December 11, 2014, Midla filed a Stipulation and Agreement (the "Midla Agreement") which resolved all of the related outstanding issues. On April 16, 2015, the FERC approved the Midla Agreement allowing Midla to retire the existing 1920s vintage pipeline and replace it with a new pipeline from Winnsboro, Louisiana to Natchez, Mississippi (the “Midla-Natchez Line”) to serve existing residential, commercial, and industrial customers. Under the Midla Agreement, customers not served by the new Midla-Natchez Line will be connected to other interstate or intrastate pipelines, other gas distribution systems, or offered conversion to propane service. On June 29, 2015, the Partnership filed with the FERC for authorization to construct the Midla-Natchez pipeline, which was approved on December 17, 2015. Construction is expected to commence in the first half of 2016 with service beginning in late 2016. Under the Midla Agreement, Midla plans to execute long-term agreements seeking to recover its investment in the Midla-Natchez Line. Commitments and contractual obligations Future non-cancelable commitments related to the following contractual obligations as of December 31, 2015 , are presented below (in thousands): Operating leases and service contracts Asset Retirement Obligation Total 2016 $ 3,721 $ 6,822 $ 10,543 2017 2,286 — 2,286 2018 1,173 — 1,173 2019 1,345 — 1,345 2020 1,006 — 1,006 Thereafter 1,537 28,549 30,086 $ 11,068 $ 35,371 $ 46,439 For the years ended December 31, 2015 , 2014 and 2013 , total expenses related to operating leases, land site leases and right-of-way agreements were $12.0 million , $5.8 million , and $1.1 million , respectively.

Related-Party Transactions

Related-Party Transactions	12 Months Ended
	Dec. 31, 2015
Related Party Transactions [Abstract]
Related-Party Transactions	Related-Party Transactions Employees of our General Partner are assigned to work for the Partnership or affiliates of our General Partner. Where directly attributable, the costs of all compensation, benefits expenses and employer expenses for these employees are charged directly by our General Partner to American Midstream, LLC, which, in turn, charges the appropriate subsidiary or affiliate. Our General Partner does not record any profit or margin for the administrative and operational services charged to us. During the years ended December 31, 2015 , 2014 , and 2013 , administrative payroll and operational services expenses of $28.7 million , $22.6 million and $14.2 million , respectively, were charged to the Partnership by our General Partner. For the years ended December 31, 2015 and 2014 , our General Partner incurred approximately $1.5 million and $0.9 million , respectively, of costs related to business development compensation that were funded by the Partnership. There were no such costs for the year ended December 31, 2013. As of December 31, 2015, the Partnership has been reimbursed for these costs. For the years ended December 31, 2015 , 2014 and 2013 , our General Partner also incurred approximately less than $0.1 million , $0.1 million and $0.8 million of costs associated with other business development activities, respectively. If the business development activities result in a project that will be pursued and funded by the Partnership, we will reimburse our General Partner for the business development costs related to that project and record those costs in our consolidated statements of operations. During the year ended December 31, 2015 , the Partnership and an affiliate of HPIP entered into arrangements under which the affiliate reimbursed the Partnership for right-of-ways purchased on the affiliate's behalf for approximately $3.9 million . During the year ended December 31, 2015 , the Partnership purchased certain equipment from an affiliate for $0.3 million . During the second quarter of 2014, the Partnership and an affiliate of its General Partner entered into a Management Service Fee arrangement under which the affiliate pays a monthly fee to reimburse the Partnership for administrative expenses incurred on the affiliate's behalf. For the years ended December 31, 2015 and 2014 , the Partnership recognized $1.4 million and $0.9 million , respectively, in management fee income that has been recorded as a reduction to Selling, general and administrative expenses . As of December 31, 2015, the Partnership had $3.8 million due to our General Partner, which has been recorded in Accrued expenses and other current liabilities and relates primarily to compensation. This payable is generally settled on a quarterly basis. As of December 31, 2014, the Partnership had $0.7 million due to our General Partner and $0.8 million due from affiliates of our General Partner, which are recorded in Accrued expenses and other current liabilities and Other current assets , respectively. Other Transactions with Affiliates On March 30, 2015 and June 30, 2015, we entered into two Series A-2 Convertible Preferred Unit Purchase Agreements with Magnolia Infrastructure Partners, LLC (an affiliate of HPIP) pursuant to which the Partnership issued, in separate private placements, newly-designated Series A-2 Units (the “Series A-2 Units”) representing limited partnership interests in the Partnership. As a result, the Partnership issued a total of 2,571,430 Series A-2 Units for approximately $45.0 million in aggregate proceeds during the year ended December 31, 2015. See Note 14 "Partners' Capital and Convertible Preferred Units" for more information. In April 2013, the High Point System, along with $15.0 million in cash, was contributed to us by HPIP in exchange for 5,142,857 Series A Units. Of the cash consideration paid by HPIP, approximately $2.5 million was used to pay certain transaction expenses of HPIP, and the remaining approximately $12.5 million was used to repay borrowings outstanding under the Partnership's former credit facility. In January 2014, in connection with the acquisition of the Lavaca System, the Partnership issued 1,168,225 Series B Units to our General Partner. The net proceeds related to the issuance was $30.0 million . In connection with the Blackwater Acquisition in December 2013, our General Partner contributed the net assets of Blackwater which were recorded at their historical book value of $22.7 million for consideration of $63.9 million , of which $27.7 million was accounted for as a cash distribution to the General Partner. The consideration also included 125,500 limited partner units which were accounted for as a non-cash distribution to the General Partner at a fair value of $3.1 million . See Note 2 "Acquisitions and Divestitures" for more information.

Reporting Segments

Reporting Segments	12 Months Ended
	Dec. 31, 2015
Segment Reporting [Abstract]
Reporting Segments	Reportable Segments Our operations are located in the United States and are organized into three reportable segments: i) Gathering and Processing, ii) Transmission and iii) Terminals. Gathering and Processing Our Gathering and Processing segment provides "wellhead-to-market" services to producers of natural gas and crude oil, which include transporting raw natural gas from the wellhead through gathering systems, treating the raw natural gas, processing raw natural gas to separate the NGLs from the natural gas, fractionating NGLs, and selling or delivering pipeline-quality natural gas and NGLs to various markets and pipeline systems. Transmission Our Transmission segment transports and delivers natural gas from producing wells, receipt points or pipeline interconnects for shippers and other customers, including local distribution companies, or LDCs, utilities and industrial, commercial and power generation customers. Terminals Our Terminals segment provides above-ground storage services at our marine terminals that support various commercial customers, including commodity brokers, refiners and chemical manufacturers to store a range of products, including petroleum products, distillates, chemicals and agricultural products. These segments are monitored separately by management for performance and are consistent with the Partnership's internal financial reporting. These segments have been identified based on the differing products and services, regulatory environment and the expertise required for these operations. Gross margin is a performance measure utilized by management to monitor the results of each segment. The following tables set forth our segment information for the periods indicated (in thousands): Year Ended December 31, 2015 Gathering and Processing Transmission Terminals Total Revenue $ 173,597 $ 43,682 $ 17,755 $ 235,034 Gain (loss) on commodity derivatives, net 1,324 — — 1,324 Total revenue 174,921 43,682 17,755 236,358 Operating expenses: Purchases of natural gas, NGL's and condensate 97,580 8,303 — 105,883 Direct operating expenses 39,189 13,720 6,640 59,549 Selling, general and administrative expenses 27,232 Equity compensation expense 3,774 Depreciation, amortization and accretion expense 38,014 Total operating expenses 234,452 Gain (loss) on sale of assets, net (3,011 ) Loss on impairment of goodwill (118,592 ) Interest expense (14,745 ) Earnings in unconsolidated affiliates 8,201 Income tax (expense) benefit (1,134 ) Income (loss) from discontinued operations, net of tax (80 ) Net income (loss) (127,455 ) Less: Net income (loss) attributable to noncontrolling interests 25 Net income (loss) attributable to the Partnership $ (127,480 ) Segment gross margin (a) $ 76,865 $ 35,301 $ 11,115 $ 123,281 Year Ended December 31, 2014 Gathering and Processing Transmission Terminals Total Revenue $ 203,616 $ 88,189 $ 15,504 $ 307,309 Gain (loss) on commodity derivatives, net 1,091 — — 1,091 Total revenue 204,707 88,189 15,504 308,400 Operating expenses: Purchases of natural gas, NGL's and condensate 152,690 45,262 — 197,952 Direct operating expenses 23,783 15,577 6,342 45,702 Selling, general and administrative expenses 23,103 Equity compensation expense 1,536 Depreciation, amortization and accretion expense 28,832 Total operating expenses 297,125 Gain (loss) on sale of assets, net (122 ) Loss on impairment of property, plant and equipment (99,892 ) Interest expense (7,577 ) Other income (expense) (670 ) Earnings in unconsolidated affiliates 348 Income tax (expense) benefit (557 ) Income (loss) from discontinued operations, net of tax (611 ) Net income (loss) (97,806 ) Less: Net income (loss) attributable to noncontrolling interests 214 Net income (loss) attributable to the Partnership $ (98,020 ) Segment gross margin (a) $ 50,817 $ 42,828 $ 9,162 $ 102,807 Year Ended December 31, 2013 Gathering and Processing Transmission Terminals (b) Total Revenue $ 205,179 $ 79,041 $ 9,831 $ 294,051 Gain (loss) on commodity derivatives, net 28 — — 28 Total revenue 205,207 79,041 9,831 294,079 Operating expenses: Purchases of natural gas, NGL's and condensate 168,574 46,479 — 215,053 Direct operating expenses 14,574 13,259 4,403 32,236 Selling, general and administrative expenses 19,079 Equity compensation expense 2,094 Depreciation, amortization and accretion expense 30,002 Total operating expenses 298,464 Gain (loss) on involuntary conversion of property, plant and equipment 343 Loss on impairment of property, plant and equipment (18,155 ) Interest expense (9,291 ) Income tax (expense) benefit 495 Income (loss) from discontinued operations, net of tax (2,413 ) Net income (loss) (33,406 ) Less: Net income (loss) attributable to noncontrolling interests 633 Net income (loss) attributable to the Partnership $ (34,039 ) Segment gross margin (a) $ 36,985 $ 32,408 $ 5,428 $ 74,821 December 31, 2015 2014 Segment assets: Gathering and Processing $ 572,824 $ 686,395 Transmission 133,870 132,767 Terminals 84,449 68,094 Other (c) 100,153 26,302 Total assets $ 891,296 $ 913,558 (a) Segment gross margin for our Gathering and Processing segment consists of revenue less purchases of natural gas, NGLs and condensate and COMA. Segment gross margin for our Transmission segment consists of revenue, less purchases of natural gas and COMA. Segment gross margin for our Terminals segment consists of revenue, less direct operating expenses. Gross margin consists of the sum of the segment gross margin amounts for each of these segments. As an indicator of our operating performance, gross margin should not be considered an alternative to, or more meaningful than, net income or cash flow from operations as determined in accordance with GAAP. Our gross margin may not be comparable to a similarly titled measure of another company because other entities may not calculate gross margin in the same manner. (b) Terminals segment amounts are for the period from April 15, 2013 to December 31, 2013. (c) Other assets not allocable to segments consist of investment in unconsolidated affiliate, corporate leasehold improvements, and other assets. For a definition of gross margin and a reconciliation to its most directly comparable financial measure calculated and presented in accordance with GAAP and a discussion of how we use gross margin to evaluate our operating performance, please read Item 7. "Management's Discussion and Analysis, How We Evaluate Our Operations." The following table summarizes the percentage of revenue earned from those customers in each segment that exceed 10% of the Partnership's consolidated segment's revenue for the each of the periods presented below: Years Ended December 31, 2015 2014 2013 Gathering and Processing: Customer A 12 % 33 % 43 % Customer B — % 12 % 19 % Customer J 12 % — % — % Other 76 % 55 % 38 % Total 100 % 100 % 100 % Transmission: Customer C — % 43 % 39 % Customer D 16 % 16 % 16 % Customer K 19 % — % — % Other 65 % 41 % 45 % Total 100 % 100 % 100 % Terminals: Customer F 13 % 19 % 20 % Customer B 13 % 20 % 17 % Customer G 21 % 15 % 16 % Customer H — % 11 % 13 % Customer I 13 % — % — % Other 40 % 35 % 34 % Total 100 % 100 % 100 %

Quarterly Financial Data (Notes

Quarterly Financial Data (Notes)	12 Months Ended
	Dec. 31, 2015
Quarterly Financial Information Disclosure [Abstract]
Quarterly Financial Information [Text Block]	Quarterly Financial Data (Unaudited) Summarized unaudited quarterly financial data for 2015 and 2014 are as follows (in thousands, except per unit amounts): First Quarter Second Quarter Third Quarter Fourth Quarter (b) Year Ended December 31, 2015 Total revenues $ 64,609 $ 67,509 $ 55,641 $ 48,599 Gross margin (a) 33,776 32,304 29,134 28,067 Operating income (loss) 3,434 1,867 (1,523 ) (123,475 ) Net income (loss) from continuing operations 835 (2,002 ) (4,574 ) (121,634 ) Income (loss) from discontinued operations, net of tax 5 (31 ) (53 ) (1 ) Net income (loss) attributable to noncontrolling interest 14 32 34 (55 ) Net income (loss) attributable to the Partnership 826 (2,065 ) (4,661 ) (121,580 ) General Partner's Interest in net income (loss) 10 (25 ) (60 ) (1,570 ) Limited Partners' Interest in net income (loss) $ 816 $ (2,040 ) $ (4,601 ) $ (120,010 ) Limited Partners' income (loss) per unit: Income (loss) from continuing operations $ (0.19 ) $ (0.35 ) $ (0.48 ) $ (4.16 ) Income (loss) from discontinued operations — — — — Net income (loss) $ (0.19 ) $ (0.35 ) $ (0.48 ) $ (4.16 ) Year Ended December 31, 2014 Total revenues $ 80,238 $ 77,680 $ 70,305 $ 80,177 Gross margin (a) 23,081 22,167 21,332 36,227 Operating income (loss) 2,450 734 (290 ) (91,633 ) Net income (loss) from continuing operations 558 (1,095 ) (2,397 ) (94,261 ) Income (loss) from discontinued operations, net of tax (50 ) (506 ) (26 ) (29 ) Net income (loss) attributable to noncontrolling interest 108 66 33 7 Net income (loss) attributable to the Partnership 400 (1,667 ) (2,456 ) (94,297 ) General Partner's Interest in net income (loss) 7 (22 ) (32 ) (1,232 ) Limited Partners' Interest in net income (loss) $ 393 $ (1,645 ) $ (2,424 ) $ (93,065 ) Limited Partners' income (loss) per unit: Income (loss) from continuing operations $ (0.31 ) $ (0.55 ) $ (0.58 ) $ (4.98 ) Income (loss) from discontinued operations (0.01 ) (0.04 ) — — Net income (loss) $ (0.32 ) $ (0.59 ) $ (0.58 ) $ (4.98 ) (a) For a definition of gross margin and a reconciliation to its most directly comparable financial measure calculated and presented in accordance with GAAP and a discussion of how we use gross margin to evaluate our operating performance, please read Item 7. "Management's Discussion and Analysis, How We Evaluate Our Operations." (b) In the fourth quarter of 2015, we recognized a Loss on impairment of goodwill of $118.6 million . In the fourth quarter of 2014, we recognized a Loss on impairment of property, plant and equipment of $99.9 million .

Organization and Basis of Pre30

Organization and Basis of Presentation (Policies)	12 Months Ended
	Dec. 31, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Nature of business	American Midstream Partners, LP (the "Partnership"), was formed on August 20, 2009 as a Delaware limited partnership for the purpose of operating, developing and acquiring a diversified portfolio of midstream energy assets. The Partnership's general partner, American Midstream GP, LLC (the "General Partner"), is 95% owned by High Point Infrastructure Partners, LLC ("HPIP") and 5% owned by AIM Midstream Holdings, LLC. We hold our assets primarily in a number of wholly owned limited liability companies, two limited partnerships and a corporation. Our capital accounts consist of notional general partner units and limited partner interests. Nature of business We are engaged in the business of gathering, treating, processing, and transporting natural gas; gathering, transporting, storing, treating and fractionating NGLs; gathering, storing and transporting crude oil and condensates; and storing specialty chemical products, all through our ownership and operation of twelve gathering systems, five processing facilities, three fractionation facilities, three marine terminal sites, three interstate pipelines, five intrastate pipelines and one crude oil pipeline. We also own a 66.7% non-operated interest in Main Pass Oil Gathering Company ("MPOG"), a crude oil gathering and processing system; a 50% undivided, non-operated interest in the Burns Point Plant, a natural gas processing plant; a 46% non-operated interest in Mesquite, an off-spec condensate fractionation project; and a 12.9% non-operated indirect interest in the Delta House floating production system and related pipeline infrastructure ("Delta House"). Our primary assets, which are strategically located in Alabama, Georgia, Louisiana, Mississippi, North Dakota, Tennessee, Texas and the Gulf of Mexico, provide critical infrastructure that links producers of natural gas, crude oil, NGLs, condensate and specialty chemicals to numerous intermediate and end-use markets. We currently operate more than 3,000 miles of pipelines that gather and transport over 1 Bcf/d of natural gas and operate approximately 1.8 million barrels of storage capacity across three marine terminal sites.
Basis of presentation	Basis of presentation We have prepared the accompanying consolidated financial statements in accordance with accounting principles generally accepted in the United States of America ("GAAP"). The results of operations for acquisitions accounted for as business combinations have been included in the consolidated financial statements since their respective acquisition dates. See Note 2 "Acquisitions and Divestitures" for further information.
Transactions Between Entities Under Common Control	Transactions Between Entities Under Common Control We may enter into transactions with our General Partner and affiliates whereby we receive a contribution of midstream assets or subsidiaries in exchange for consideration from the Partnership. We account for the net assets received using the historical book value of the asset or subsidiary being contributed or transferred as these are transactions between entities under common control. Our historical financial statements may be revised to include the results attributable to the assets contributed from our General Partner as if we owned such assets for all periods presented by the Partnership since either the change in control of our General Partner, effective April 15, 2013 or later.
Consolidation policy	Consolidation policy The accompanying consolidated financial statements include accounts of American Midstream Partners, LP, and its controlled subsidiaries. All significant inter-company accounts and transactions have been eliminated in the preparation of the accompanying consolidated financial statements.
Equity Method Investments	Investment in Unconsolidated Affiliates Equity investments in which the Partnership exercises significant influence, but does not control and is not the primary beneficiary, are accounted for using the equity method and are reported in Investment in unconsolidated affiliates in the accompanying consolidated balance sheets. The Partnership believes the equity method is an appropriate means for it to recognize increases or decreases measured by GAAP in the economic resources underlying the investments. Regular evaluation of these investments is appropriate to evaluate any potential need for impairment. The Partnership uses evidence of a loss in value to identify if an investment has declined in value, other than a temporary decline. The Partnership accounts for its 66.7% non-operated interest in MPOG, its 46.0% non-operated interest in Mesquite and its 12.9% non-operated indirect interest in Delta House under the equity method.
Use of estimates	Use of estimates When preparing consolidated financial statements in conformity with GAAP, management must make estimates and assumptions based on information available at the time. These estimates and assumptions affect the reported amounts of assets, liabilities, revenues and expenses, as well as the disclosures of contingent assets and liabilities as of the date of the financial statements. Estimates and assumptions are based on information available at the time such estimates and assumptions are made. Adjustments made with respect to the use of these estimates and assumptions often relate to information not previously available. Uncertainties with respect to such estimates and assumptions are inherent in the preparation of financial statements. Estimates and assumptions are used in, among other things, i) estimating unbilled revenues, product purchases and operating and general and administrative costs, ii) developing fair value assumptions, including estimates of future cash flows and discount rates, iii) analyzing long-lived assets, goodwill and intangible assets for possible impairment, iv) estimating the useful lives of assets and v) determining amounts to accrue for contingencies, guarantees and indemnifications. Actual results, therefore, could differ materially from estimated amounts.
Cash and cash equivalents	Cash and cash equivalents We consider all highly liquid investments with an original maturity of three months or less at the date of purchase to be cash equivalents. The carrying value of cash and cash equivalents approximates fair value because of the short term to maturity of these investments.
Allowance for doubtful accounts	Allowance for doubtful accounts We establish provisions for losses on accounts receivable when we determine that we will not collect all or part of an outstanding balance. Collectability is reviewed regularly and an allowance is established or adjusted, as necessary, using the specific identification method. As of December 31, 2015 and 2014 , the Partnership recorded no allowances for losses on accounts receivable.
Operational balancing agreements and natural gas imbalances	Operational balancing agreements and natural gas imbalances To facilitate deliveries of natural gas and provide for operational flexibility, we have operational balancing agreements in place with other interconnecting pipelines. These agreements ensure that the volume of natural gas a shipper schedules for transportation between two interconnecting pipelines equals the volume actually delivered. If natural gas moves between pipelines in volumes that are more or less than the volumes the shipper previously scheduled, a natural gas imbalance is created. The imbalances are settled through periodic cash payments or repaid in-kind through future receipt or delivery of natural gas. Natural gas imbalances are recorded as gas imbalances and classified within Other current assets or Other current liabilities on our consolidated balance sheets at cost which approximates fair value.
Derivative financial instruments	Derivative financial instruments Our net income (loss) and cash flows are subject to volatility stemming from changes in interest rates on our variable rate debt, commodity prices and fractionation margins (the relative difference between the price we receive from NGL sales and the corresponding cost of natural gas purchases). In an effort to manage the risks to unitholders, we use a variety of derivative financial instruments including swaps, collars and interest rate caps to create offsetting positions to specific commodity or interest rate exposures. In accordance with the authoritative accounting guidance, we record all derivative financial instruments in our consolidated balance sheets at fair value as current and long-term assets or liabilities on a net basis by counterparty. We record changes in the fair value of our derivative financial instruments in our consolidated statements of operations as follows: • Commodity-based derivatives: "Total revenue" • Corporate interest rate derivatives: "Interest expense" Our formal hedging program provides a control structure and governance for our hedging activities specific to identified risks and time periods, which are subject to the approval and monitoring by the Board of Directors of our General Partner. We employ derivative financial instruments in connection with an underlying asset, liability or anticipated transaction, and we do not use derivative financial instruments for speculative or trading purposes. The price assumptions we use to value our derivative financial instruments can affect net income (loss) for each period. We use published market price information where available, or quotations from over-the-counter, or OTC, market makers to find executable bids and offers. The valuations also reflect the potential impact of conditions, including credit risk of our counterparties. The amounts reported in our consolidated financial statements change quarterly as these valuations are revised to reflect actual results, changes in market conditions or other factors, many of which are beyond our control.
Fair value measurements	Fair value measurements We apply the authoritative accounting provisions for measuring fair value of our derivative instruments and disclosures associated with our outstanding indebtedness. We define fair value as an exit price representing the expected amount we would receive when selling an asset or pay to transfer a liability in an orderly transaction with market participants at the measurement date. We use various assumptions and methods in estimating the fair values of our financial instruments. The carrying amounts of cash and cash equivalents, accounts receivable and accounts payable approximated their fair value due to the short-term maturity of these instruments. The carrying amount of our various credit facilities approximate fair value, because the interest rates on these facilities are variable. We employ a hierarchy which prioritizes the inputs we use to measure recurring fair value into three distinct categories based upon whether such inputs are observable in active markets or unobservable. We classify assets and liabilities in their entirety based on the lowest level of input that is significant to the fair value measurement. Our methodology for categorizing assets and liabilities that are measured at fair value pursuant to this hierarchy gives the highest priority to unadjusted quoted prices in active markets and the lowest level to unobservable inputs as outlined below: • Level 1 – Inputs represent unadjusted quoted prices in active markets for identical assets or liabilities; • Level 2 – Inputs include quoted prices for similar assets and liabilities in active markets that are either directly or indirectly observable; and • Level 3 – Inputs are unobservable and considered significant to fair value measurement. We utilize a mid-market pricing convention, or the "market approach," for valuation for assigning fair value to our derivative assets and liabilities. Our credit exposure for over-the-counter derivatives is directly with our counterparty and continues until the maturity or termination of the contracts. As appropriate, valuations are adjusted for various factors such as credit and liquidity considerations.
Property, plant and equipment	Property, plant and equipment We capitalize expenditures related to property, plant and equipment that have a useful life greater than one year for assets purchased or constructed; existing assets that are replaced, improved, or the useful lives of which have been extended; and all land, regardless of cost. Maintenance and repair costs, including any planned major maintenance activities, are expensed as incurred. We record property, plant, and equipment at its original cost, which we depreciate on a straight-line basis over its estimated useful life. Our determination of the useful lives of property, plant and equipment requires us to make various assumptions, including the supply of and demand for hydrocarbons in the markets served by our assets, normal wear and tear of the facilities, and the extent and frequency of maintenance programs. We record depreciation using the group method of depreciation, which is commonly used by pipelines, utilities and similar assets. We classify long-lived assets to be disposed of through sales that meet specific criteria as held for sale. We cease depreciating those assets effective on the date the asset is classified as held for sale. We record those assets at the lower of their carrying value or the estimated fair value less the cost to sell. Until the assets are disposed of, an estimate of the fair value is re-determined when related events or circumstances change.
Impairment of long lived Assets	Impairment of long lived Assets We evaluate the recoverability of our property, plant and equipment and intangible assets with definite lives when events or circumstances indicate we may not recover the carrying amount of the assets. We continually monitor our operations, the market, and business environment to identify indicators that could suggest an asset or asset group may not be recoverable. We evaluate the asset or asset group for recoverability by estimating the undiscounted future cash flows expected to be derived from their use and disposition. These cash flow estimates require us to make projections and assumptions for many years into the future for pricing, demand, competition, operating cost, contract renewals, and other factors. An asset or asset group is considered impaired when the estimated undiscounted cash flows are less than the carrying amount. In that event, an impairment loss is recognized to the extent that the carrying amount of the asset or asset group exceeds its fair value as determined by quoted market prices in active markets or present value techniques. The determination of fair values using present value techniques requires us to make projections and assumptions regarding future cash flows and weighted average cost of capital. Any changes we make to these projections and assumptions could result in significant revisions to our evaluation of the recoverability of our property, plant and equipment and the recognition of an impairment loss in our consolidated statements of operations.
Goodwill and intangible assets	Goodwill and intangible assets We record goodwill for the excess of the cost of an acquisition over the fair value of the net assets of the acquired business. Goodwill is not amortized but is reviewed for impairment at least annually or more frequently if an event or change in circumstance indicates that an impairment may have occurred. We first assess qualitative factors to evaluate whether it is more likely than not that an impairment has occurred and it is therefore necessary to perform the two-step goodwill impairment test. If the two-step goodwill impairment test indicates that the goodwill is impaired, an impairment loss is recorded. We record the estimated fair value of acquired customer contracts, relationships and dedicated acreage agreements as intangible assets. These intangible assets have definite lives and are subject to amortization on a straight-line basis over their economic lives, currently ranging between 10 years and 30 years . We assess intangible assets for impairment together with related underlying long-lived assets whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable.
Deferred financing costs	Deferred financing costs Costs incurred in connection with our revolving credit facility are deferred and charged to interest expense over the term of the related credit arrangement. Gains or losses on debt repurchase and debt extinguishment include any associated unamortized deferred financing costs.
Asset retirement obligations (AROs)	Asset retirement obligations ("AROs") AROs are legal obligations associated with the retirement of tangible long-lived assets that result from the asset's acquisition, construction, development and operation. An ARO is initially measured at its estimated fair value. Upon initial recognition, we also record an increase to the carrying amount of the related long-lived asset. We depreciate the asset using the straight-line method over the period during which it is expected to provide benefits. After initial recognition, we revise the ARO to reflect the passage of time and for changes in the estimated amount or timing of cash flows. We have legal obligations requiring us to decommission our offshore pipeline systems at retirement. In certain rate jurisdictions, we are permitted to include annual charges for removal costs in the regulated cost of service rates we charge our customers. Additionally, legal obligations exist for a minority of our offshore right-of-way agreements due to requirements or landowner options to compel us to remove the pipe at final abandonment. Sufficient data exists with certain onshore pipeline systems to reasonably estimate the cost of abandoning or retiring a pipeline system. However, in some cases, there is insufficient information to reasonably determine the timing and/or method of settlement of estimating the fair value of the asset retirement obligation. In these cases, the asset retirement obligation cost is considered indeterminate because there is no data or information that can be derived from past practice, industry practice, management's experience, or the asset's estimated economic life. The useful lives of most pipeline systems are primarily derived from available supply resources and ultimate consumption of those resources by end users. Variables can affect the remaining lives of the assets which preclude us from making a reasonable estimate of the asset retirement obligation. Indeterminate asset retirement obligation costs will be recognized in the period in which sufficient information exists to reasonably estimate potential settlement dates and methods.
Commitments, contingencies and environmental liabilities	Commitments, contingencies and environmental liabilities We expense or capitalize, as appropriate, expenditures for ongoing compliance with environmental regulations that relate to past or current operations. We expense amounts we incur from the remediation of existing environmental contamination caused by past operations that do not benefit future periods by preventing or eliminating future contamination. We record liabilities for environmental matters when assessments indicate that remediation efforts are probable and the costs can be reasonably estimated. Estimates of environmental liabilities are based on currently available facts, existing technology and presently enacted laws and regulation taking into consideration the likely effects of inflation and other factors. These amounts also take into account our prior experience in remediating contaminated sites, other companies' clean-up experience and data released by government organizations. Our estimates are subject to revision in future periods based on actual cost or new information. We evaluate recoveries from insurance coverage separately from the liability and, when recovery is probable, we record an asset separately from the associated liability in our consolidated financial statements. We recognize liabilities for other commitments and contingencies when, after fully analyzing the available information, we determine it is either probable that an asset has been impaired or that a liability has been incurred and the amount of impairment or loss can be reasonably estimated. When a range of probable loss can be estimated, we accrue the most likely amount or if no amount is more likely than another, we accrue the minimum of the range of probable loss. We expense legal costs associated with loss contingencies as such costs are incurred.
Noncontrolling interests	Noncontrolling interests Noncontrolling interests represent the minority interest holders' proportionate share of the equity of the respective systems. Noncontrolling interests are adjusted for the minority interest holders' proportionate share of the earnings or losses. Management reports noncontrolling interest in the Chatom system in the financial statements pursuant to paragraph ASC 810-10-65-1. The 7.8% noncontrolling interest is held by non-affiliated working interest owners
Revenue recognition and the estimation of revenues and cost of purchases	Revenue recognition and the estimation of revenues and cost of purchases We recognize revenue when all of the following criteria are met: i) persuasive evidence of an exchange arrangement exists, ii) delivery has occurred or services have been rendered, iii) the price is fixed or determinable, and iv) collectability is reasonably assured. We record revenue and cost of product sold on a gross basis for those transactions where we act as the principal and take title to natural gas, crude oil, NGLs or condensates that are purchased for resale. When our customers pay us a fee for providing a service such as gathering, treating, transportation or storage, we record those fees separately in revenues.
Equity-based compensation	Equity-based compensation We award equity-based compensation to management, non-management employees and directors under our Long-Term Incentive Plan ("LTIP"), which provides for the issuance of options, unit appreciation rights, restricted units, phantom units, other unit-based awards, unit awards or replacement awards, as well as tandem Distribution Equivalent Rights ("DERs"). Compensation expense is measured by the fair value of the award at the date of grant as determined by management. Compensation expense is recognized in Equity compensation expense over the requisite service period of each award.
Income taxes	Income taxes The Partnership is not a taxable entity for U.S. federal income tax purposes or for the majority of states that impose an income tax. Taxes on our net income are generally borne by our unitholders through the allocation of taxable income. American Midstream Blackwater, LLC, a subsidiary of the Partnership, owns a subsidiary that has operations which are subject to both federal and state income taxes. We account for income taxes of that subsidiary using an asset and liability approach for financial accounting and reporting of income taxes. If it is more than likely that a deferred tax asset will not be realized, a valuation allowance is recognized. Certain tax expense results from the enactment of laws by the State of Texas that apply to entities organized as partnerships and is included in Income tax (expense) benefit in our consolidated statements of operations. The Texas margin tax is computed on our taxable margin apportioned to Texas annually. Net income (loss) for financial statement purposes may differ significantly from taxable income (loss) allocable to unitholders as a result of differences between the financial reporting and income tax bases of our assets and liabilities and the taxable income allocation requirement under our Partnership Agreement. The aggregate difference in the basis of our net assets for financial and tax reporting purposes cannot be readily determined because information regarding each partner's tax attributes in us is not available.
Accumulated other comprehensive income (loss)	Accumulated other comprehensive income (loss) Accumulated other comprehensive income (loss) is comprised solely of adjustments related to the Partnership's postretirement benefit plan.
Limited partners' net income (loss) per unit	Limited partners' net income (loss) per unit We compute earnings per unit using the two-class method. The two-class method requires that securities that meet the definition of a participating security be considered for inclusion in the computation of basic earnings per unit. Under the two-class method, earnings per unit is calculated as if all of the earnings for the period were distributed under the terms of the Partnership Agreement, regardless of whether the General Partner has discretion over the amount of distributions to be made in any particular period, whether those earnings would actually be distributed during a particular period from an economic or practical perspective, or whether the General Partner has other legal or contractual limitations on its ability to pay distributions that would prevent it from distributing all of the earnings for a particular period. The two-class method does not impact our overall net income or other financial results; however, in periods in which aggregate net income exceeds our aggregate distributions for such period, it will have the impact of reducing net income per limited partner unit. This result occurs as a larger portion of our aggregate earnings, as if distributed, is allocated to the incentive distribution rights of the General Partner, even though we make distributions on the basis of available cash and not earnings. In periods in which our aggregate net income does not exceed our aggregate distributions for such period, the two-class method does not have any impact on our calculation of earnings per limited partner unit.

Recent Accounting Pronouncement

Recent Accounting Pronouncements Policies (Policies)	12 Months Ended
	Dec. 31, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
New Accounting Pronouncements	Recent Accounting Pronouncements In May 2014, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") No. 2014-09, Revenue from Contracts with Customers (Topic 606), which amends the existing accounting standards for revenue recognition. The standard requires an entity to recognize revenue in a manner that depicts the transfer of goods or services to customers at an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. ASU 2015-14 was subsequently issued and deferred the effective date to annual reporting periods beginning after December 15, 2017, including interim reporting periods within that period. We are currently evaluating the method of adoption and impact this standard will have on our consolidated financial statements and related disclosures. In February 2015, the FASB issued ASU No. 2015-02, Consolidation - Amendments to the Consolidation Analysis, which amends the current consolidation guidance. The amendments affect both the variable interest entity ("VIE") and voting interest entity ("VOE") consolidation models. The standard is effective for public reporting entities in the fiscal periods beginning after December 15, 2015, early adoption is permitted. The Partnership has evaluated the impact of this standard on its consolidated financial statements and determined it will not have a material impact. In April 2015, the FASB issued ASU No. 2015-03, Simplifying the Presentation of Debt Issuance Costs. This amendment requires that debt issuance costs related to a recognized debt liability be presented in the balance sheet as a direct deduction from the carrying amount of that debt liability, consistent with debt discounts. ASU 2015-03 is effective for fiscal years beginning after December 15, 2015, including interim periods therein, and is applied retrospectively. Early adoption is permitted for financial statements that have not been previously issued. ASU 2015-15, Presentation and Subsequent Measurement of Debt Issue Costs Associated with Line of Credit Arrangements, was subsequently issued to address the absence of authoritative guidance for debt issuance costs related to line-of-credit arrangements and states that the Securities and Exchange Commission ("SEC") staff will not object to an entity deferring and presenting debt issuance costs as an asset and subsequently amortizing the deferred debt issuance costs ratably over the term of the line-of-credit arrangement. Given the Partnership's debt issuance costs relate to its Credit Agreement (as defined in Note 13 "Debt Obligations"), the Partnership is not required to alter its current accounting for such costs. In April 2015, the FASB issued ASU No. 2015-05, Intangibles — Goodwill and Other — Internal-Use Software (Subtopic 350-40) , which assists entities in evaluating the accounting for fees paid by a customer in a cloud computing arrangement by providing guidance as to whether an arrangement includes the sales or license of software. The amendment will be effective prospectively for reporting periods beginning on or after December 15, 2015, and early adoption is permitted. The Partnership has evaluated the impact of this standard on its financial statements and determined it will not have a material impact. In April 2015, the FASB issued ASU No. 2015-06, Earnings Per Share (Topic 260) . This guidance clarifies the process for updating historical earnings per unit disclosures when a drop-down transaction occurs between entities under common control. Pursuant to the amendment, the earnings (losses) of a transferred business before the date of a dropdown transaction should be allocated entirely to the general partner. Additionally, the previously reported earnings per unit measure presented in the historical financial statements would not change as a result of the drop-down transaction. ASU 2015-06 is effective for annual reporting periods beginning after December 15, 2015, and for interim periods within those fiscal years. Early adoption is permitted. The Partnership has evaluated this guidance and determined it will not have a material impact. In September 2015, the FASB issued ASU No. 2015-16, Business Combinations (Topic 805). This amendment requires that an acquirer recognize adjustments to provisional amounts that are identified during the measurement period in the reporting period in which the adjustment amounts are determined. ASU 2015-16 is effective for fiscal years beginning after December 15, 2015, including interim periods within those fiscal years. Early adoption is permitted for financial statements that have not been issued. The Partnership has evaluated this guidance and determined it is consistent with our policy and historical presentation. In November 2015, the FASB issued ASU 2015-17, Income Taxes (Topic 740). This amendment requires that deferred tax liabilities and assets be classified as noncurrent. ASU 2015-17 is effective for fiscal years beginning after December 15, 2016, including interim periods within those fiscal years. Early adoption is permitted. The Partnership has evaluated this guidance and elected to adopt this amendment for the fiscal year ended December 31, 2015. As such, the Partnership’s deferred tax liabilities and assets have been classified as noncurrent in the consolidated balance sheets as of December 31, 2015, and 2014. In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842). This amendment requires the recognition of lease assets and lease liabilities by lessees for those leases classified as operating leases under previous GAAP. ASU 2016-02 is effective for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. Early adoption is permitted. We are currently evaluating the method of adoption and impact this standard will have on our consolidated financial statements and related disclosures.

Acquisitions (Tables)

Acquisitions (Tables)	12 Months Ended
	Dec. 31, 2015
Business Combinations [Abstract]
Schedule of business acquisitions	The following table summarizes the fair value of consideration transferred to acquire Costar and the allocation of that amount to the assets acquired, liabilities assumed and the noncontrolling interest for the Costar Acquisition based upon their respective fair values as of the acquisition date (in thousands). Fair value of consideration transferred (in thousands): Cash $ 258,001 Limited partner common units 147,296 Total fair value of consideration $ 405,297
Schedule of recognized identified assets acquired and liabilities assumed	The following table summarizes the final allocation of the purchase price to the assets acquired in the Lavaca Acquisition based upon their respective fair values as of the acquisition date (in thousands): Property, plant and equipment: Land $ 2 Pipelines 58,737 Equipment 753 Total property, plant and equipment 59,492 Intangible assets 21,350 Goodwill 23,567 Total cash consideration $ 104,409 Fair Value of assets acquired, liabilities assumed and noncontrolling interest (in thousands): Working capital $ 8,152 Property, plant and equipment: Processing plants $ 48,357 Pipelines 128,799 Land 1,244 Buildings 682 Equipment 9,827 Construction in progress 16,146 Total property, plant and equipment 205,055 Investment in unconsolidated affiliate 11,884 Intangible assets: Customer relationships 53,400 Dedicated acreage 32,000 Goodwill 95,025 Noncontrolling interest (219 ) $ 405,297
Unaudited pro forma consolidated information of the partnership, adjusted for the acquisition of the Costar assets	The following unaudited pro forma summary presents consolidated financial information for the Partnership as if the Costar acquisition had occurred on January 1, 2013 (in thousands): Years Ended December 31, 2014 2013 Revenue $ 435,133 $ 448,748 Net loss (101,237 ) (30,672 ) Limited partners' net loss per unit (6.15 ) (3.82 )

Discontinued Operations (Tables

Discontinued Operations (Tables)	12 Months Ended
	Dec. 31, 2015
Discontinued Operations and Disposal Groups [Abstract]
Schedule of Disposal Groups, Including Discontinued Operations, Income Statement, Balance Sheet and Additional Disclosures [Table Text Block]	The following table presents the revenue, expense and (loss) gain from discontinued operations associated with the assets classified as held for sale for the years ended December 31, 2015 , 2014 , and 2013 (in thousands, except per unit amounts): Years Ended December 31, 2015 2014 2013 Revenue $ 74 $ 474 $ 2,084 Expense (196 ) (658 ) (2,361 ) Impairment — (673 ) (2,400 ) Loss on sale of assets (150 ) (87 ) (75 ) Income tax benefit 192 333 339 Income (loss) from discontinued operations, net of tax $ (80 ) $ (611 ) $ (2,413 ) Limited partners' net income (loss) per unit from discontinued operations (basic and diluted) $ — $ (0.04 ) $ (0.27 )

Concentration of Credit Risk 34

Concentration of Credit Risk and Trade Accounts Receivable (Tables)	12 Months Ended
	Dec. 31, 2015
Receivables [Abstract]
Percentage of revenue earned from major customers	The following table summarizes those customers who accounted for more than 10% of the Partnership's consolidated revenue for the each of the last three years: Years Ended December 31, 2015 2014 2013 Customer A 10 % 22 % 28 % Customer B — % — % 13 % Customer C — % 12 % 12 % Customer D — % 10 % 10 % Other 90 % 56 % 37 % Total 100 % 100 % 100 % The following table summarizes the percentage of revenue earned from those customers in each segment that exceed 10% of the Partnership's consolidated segment's revenue for the each of the periods presented below: Years Ended December 31, 2015 2014 2013 Gathering and Processing: Customer A 12 % 33 % 43 % Customer B — % 12 % 19 % Customer J 12 % — % — % Other 76 % 55 % 38 % Total 100 % 100 % 100 % Transmission: Customer C — % 43 % 39 % Customer D 16 % 16 % 16 % Customer K 19 % — % — % Other 65 % 41 % 45 % Total 100 % 100 % 100 % Terminals: Customer F 13 % 19 % 20 % Customer B 13 % 20 % 17 % Customer G 21 % 15 % 16 % Customer H — % 11 % 13 % Customer I 13 % — % — % Other 40 % 35 % 34 % Total 100 % 100 % 100 %

Other Current Assets (Tables)

Other Current Assets (Tables)	12 Months Ended
	Dec. 31, 2015
Other Current Assets [Abstract]
Schedule of other current assets	Other current assets consists of the following (in thousands): December 31, 2015 2014 Prepaid insurance—current portion $ 3,948 $ 4,162 Restricted cash — 6,475 Other prepaid amounts 2,866 758 Other current assets 3,280 4,159 $ 10,094 $ 15,554 Restricted cash of $6.5 million as of December 31, 2014 consisted of a cash-backed letter of credit related to Costar operations that the Partnership was contractually obligated to maintain after the Costar Acquisition. The Partnership was released from this obligation in January 2015. Other current assets primarily consist of natural gas imbalances and amounts due from related parties.

Derivatives (Tables)

Derivatives (Tables)	12 Months Ended
	Dec. 31, 2015
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Fair value associated with commodity derivative instruments	As of December 31, 2015 and 2014 , the value associated with our commodity derivatives, interest rate swap and weather derivative were recorded in our consolidated balance sheets, under the captions as follows (in thousands): Gross Risk Management Assets Gross Risk Management Liabilities Net Risk Management Assets (Liabilities) Balance Sheet Classification December 31, 2015 December 31, 2014 December 31, 2015 December 31, 2014 December 31, 2015 December 31, 2014 Current $ 365 $ 688 $ — $ — $ 365 $ 688 Noncurrent — — — — — — Total assets $ 365 $ 688 $ — $ — $ 365 $ 688 Current $ — $ — $ — $ (215 ) $ — $ (215 ) Noncurrent — — — — — — Total liabilities $ — $ — $ — $ (215 ) $ — $ (215 )
Realized and unrealized gains (losses) with commodity and interst rate derivative instruments	For the years ended December 31, 2015 , 2014 and 2013 , the realized and unrealized gains (losses) associated with our commodity, interest rate and weather derivative instruments were recorded in our consolidated statements of operations, under the captions as follows (in thousands): Realized Unrealized 2015 Gain (loss) on commodity derivatives, net $ 1,610 $ (286 ) Interest expense (240 ) 215 Direct operating expenses (913 ) — Total $ 457 $ (71 ) 2014 Gain (loss) on commodity derivatives, net $ 735 $ 356 Interest expense (433 ) 239 Direct operating expenses (1,035 ) — Total $ (733 ) $ 595 2013 Gain (loss) on commodity derivatives, net $ 1,069 $ (1,041 ) Interest expense (207 ) (454 ) Direct operating expenses (662 ) — Total $ 200 $ (1,495 )

Fair Value Measurement (Tables)

Fair Value Measurement (Tables)	12 Months Ended
	Dec. 31, 2015
Fair Value Disclosures [Abstract]
Fair value of financial instruments	Fair Value of Financial Instruments The following table sets forth by level within the fair value hierarchy, our commodity derivative instruments and interest rate swap, included as part of Risk management assets and Risk management liabilities within the consolidated balance sheets, that were measured at fair value on a recurring basis as of December 31, 2015 and 2014 (in thousands): Carrying Amount Estimated Fair Value of the Asset (Liability) Level 1 Level 2 Level 3 Total Commodity derivative instruments, net December 31, 2015 $ — $ — $ — $ — $ — December 31, 2014 286 — 286 — 286 Interest rate swap December 31, 2015 $ — $ — $ — $ — $ — December 31, 2014 (215 ) — (215 ) — (215 ) The unamortized portion of the premium paid to enter the weather derivative described in Note 6 "Derivatives," is included within Risk management assets on the consolidated balance sheets but is not included in the above table as it is recorded at amortized cost, not fair value.

Property, Plant and Equipment38

Property, Plant and Equipment, Net (Tables)	12 Months Ended
	Dec. 31, 2015
Property, Plant and Equipment [Abstract]
Property, plant, and equipment, net	Property, plant and equipment, net, as of December 31, 2015 and 2014 , were as follows (in thousands): Useful Life (in years) December 31, December 31, Land N/A $ 5,282 $ 5,282 Construction in progress N/A 46,045 77,550 Buildings and improvements 4 to 40 9,864 6,855 Processing and treating plants 8 to 40 97,784 80,837 Pipelines and compressors 3 to 40 554,400 476,997 Storage 20 to 40 58,394 38,151 Equipment 5 to 20 22,207 12,345 Total property, plant and equipment 793,976 698,017 Accumulated depreciation (145,963 ) (115,835 ) Property, plant and equipment, net $ 648,013 $ 582,182

Goodwill and Intangible asset39

Goodwill and Intangible assets (Tables)	12 Months Ended
	Dec. 31, 2015
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Finite-Lived Intangible Assets [Table Text Block]	Intangible assets, net, consist of the following (in thousands): December 31, 2015 2014 Gross carrying amount: Customer contracts $ 12,101 $ 12,101 Customer relationships 53,400 53,400 Dedicated acreage 53,350 53,350 $ 118,851 $ 118,851 Accumulated amortization: Customer contracts $ (12,101 ) $ (11,110 ) Customer relationships (3,124 ) (553 ) Dedicated acreage (2,661 ) (882 ) $ (17,886 ) $ (12,545 ) Net carrying amount: Customer contracts $ — $ 991 Customer relationships 50,276 52,847 Dedicated acreage 50,689 52,468 $ 100,965 $ 106,306

Investment in unconsolidated 40

Investment in unconsolidated affiliates (Tables)	12 Months Ended
	Dec. 31, 2015
Equity Method Investments and Joint Ventures [Abstract]
Investments in and Advances to Affiliates [Table Text Block]	The following table presents the activity in the Partnership's equity investments (in thousands): MPOG Mesquite Pinto/Delta House Total 66.7% 46% 12.9% Balances at December 31, 2013 $ — $ — $ — $ — Initial investment 12,000 11,884 — 23,884 Earnings in unconsolidated affiliates 348 — — 348 Distributions (1,980 ) — — (1,980 ) Balances at December 31, 2014 $ 10,368 $ 11,884 $ — $ 22,252 Initial investment — — 65,703 65,703 Earnings in unconsolidated affiliates 731 — 7,470 8,201 Contributions — 6,713 — 6,713 Distributions (3,920 ) — (16,648 ) (20,568 ) Balances at December 31, 2015 $ 7,179 $ 18,597 $ 56,525 $ 82,301
Equity Method Investments [Table Text Block]	The following tables present the summarized combined financial information for the Partnership's equity investments (amounts represent 100% of investee financial information): Years Ended December 31, Balance Sheets: 2015 2014 Current assets $ 2,086 $ 2,196 Non-current assets 288,617 62,635 Current liabilities 366 398 Non-current liabilities 23,617 22,307 Years Ended December 31, Income Statements: 2015 2014 2013 Total revenue $ 37,724 $ 3,847 $ — Operating expense 3,375 1,722 — Net income 29,437 510 —

Accrued Expenses and Other Cu41

Accrued Expenses and Other Current Liabilities (Tables)	12 Months Ended
	Dec. 31, 2015
Payables and Accruals [Abstract]
Schedule of accrued expenses and other current liabilities	Accrued expenses and other current liabilities were as follows (in thousands): December 31, 2015 2014 Current portion of asset retirement obligation $ 6,822 $ — Accrued capital expenditures 3,984 17,134 Accrued expenses 3,178 4,560 Due to related parties 3,894 659 Gas imbalances payable 413 1,055 Other 6,744 2,392 $ 25,035 $ 25,800

Asset Retirement Obligation (Ta

Asset Retirement Obligation (Tables)	12 Months Ended
	Dec. 31, 2015
Asset Retirement Obligation Disclosure [Abstract]
Schedule of reconciliation of the beginning and ending aggregate carrying amount of ARO liabilities	The following table presents activity in the Partnership's asset retirement obligations (in thousands): Years Ended December 31, 2015 2014 Beginning asset retirement obligation $ 34,645 $ 34,636 Liabilities assumed — 248 Expenditures (91 ) (1,030 ) Accretion expense 817 791 Total ending asset retirement obligation 35,371 34,645 Less: current portion 6,822 — Long-term asset retirement obligation $ 28,549 $ 34,645

Debt Obligations (Tables)

Debt Obligations (Tables)	12 Months Ended
	Dec. 31, 2015
Debt Disclosure [Abstract]
Outstanding borrowings under the credit facility	Our outstanding borrowings under the credit facility were (in thousands): December 31, 2015 2014 Revolving credit facility $ 525,100 $ 372,950 Other debt 2,338 2,908 Total debt 527,438 375,858 Less: current portion 2,338 2,908 Long-term debt $ 525,100 $ 372,950

Partners' Capital (Tables)

Partners' Capital (Tables)	12 Months Ended
	Dec. 31, 2015
Equity [Abstract]
Schedule for number of units outstanding	The numbers of units outstanding were as follows (in thousands): December 31, 2015 2014 2013 Series A convertible preferred units 9,210 5,745 5,279 Series B convertible units 1,350 1,255 — Limited Partner common units 30,427 22,670 7,414 General Partner units 536 392 185
Distributions Made to Limited Partner, by Distribution	We made cash distributions as follows (in thousands): Years Ended December 31, 2015 2014 2013 Series A convertible preferred units $ — $ 2,658 $ 2,375 Limited Partner common units 46,597 22,656 8,207 Limited Partner subordinated units — — 5,073 General Partner units 1,187 333 284 General Partners' incentive distribution rights 5,602 2,362 181 $ 53,386 $ 28,009 $ 16,120

Earnings per Unit (Tables)

Earnings per Unit (Tables)	12 Months Ended
	Dec. 31, 2015
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Schedule of Earnings Per Share, Basic and Diluted, Per General and Limited Partner Unit, Including Two Class Method [Table Text Block]	We determined basic and diluted net income (loss) per limited partner unit as follows, (in thousands, except per unit amounts): Years Ended December 31, 2015 2014 2013 Net income (loss) from continuing operations $ (127,375 ) $ (97,195 ) $ (30,993 ) Net income (loss) attributable to noncontrolling interests 25 214 633 Net income (loss) from continuing operations attributable to the Partnership (127,400 ) (97,409 ) (31,626 ) Less: Distributions on Series A preferred units 16,978 14,492 24,117 Declared distributions on Series B Units 1,373 2,220 — General partner's distributions 6,790 2,694 464 General partner's share in undistributed loss (2,569 ) (1,820 ) (1,708 ) Blackwater net loss from continuing operations — — (716 ) Net income (loss) from continuing operations available to limited Partners (149,972 ) (114,995 ) (53,783 ) Net income (loss) from discontinued operations available to Limited Partners (80 ) (603 ) (2,051 ) Net income (loss) available to Limited Partners $ (150,052 ) $ (115,598 ) $ (55,834 ) Weighted average number of units used in computation of Limited Partners' net income (loss) per unit (basic and diluted) 24,983 13,472 7,525 Limited Partners' net income (loss) from continuing operations per unit (basic and diluted) $ (6.00 ) $ (8.54 ) $ (7.15 ) Limited Partners' net income (loss) from discontinued operations per unit (basic and diluted) — (0.04 ) (0.27 ) Limited Partners' net income (loss) per unit (basic and diluted) $ (6.00 ) $ (8.58 ) $ (7.42 )

Long-Term Incentive Plan (Table

Long-Term Incentive Plan (Tables)	12 Months Ended
	Dec. 31, 2015
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Schedule of Share-based Compensation Restricted Stock and Restricted Stock Units Activity	The following table summarizes our phantom unit-based awards, in units: Years Ended December 31, Units Weighted-Average Exercise Price Outstanding at beginning of period 201,132 $ 19.85 Granted 546,329 12.25 Forfeited (31,298 ) 15.62 Vested (146,404 ) 18.47 Outstanding at end of period 569,759 $ 13.15
Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions	The fair value of each unit-based option award is estimated on the date of grant using a Black-Scholes pricing model that incorporates the assumptions noted in the following table. Weighted average volatility 47.0 % Expected dividend yield 26.3 % Weighted average expected term (in years) 3.5 Weighted average risk-free rate 1.3 %
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value	The following table summarizes our Option Grant awards, in units: Year Ended December 31, 2015 Units Weighted-Average Exercise Price Outstanding at beginning of period — $ — Granted 200,000 7.50 Forfeited — — Vested — — Outstanding at end of period 200,000 $ 7.50

Income Tax (Tables)

Income Tax (Tables)	12 Months Ended
	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Schedule of Deferred Tax Assets and Liabilities [Table Text Block]	The Partnership’s deferred tax assets and liabilities as of December 31, 2015 and 2014 are summarized below: December 31, 2015 2014 Deferred tax assets: Net operating loss carryforwards $ 7,570 $ 4,173 Other 493 213 Total deferred tax assets 8,063 4,386 Deferred tax liabilities: Property, plant and equipment 13,889 9,112 Intangible assets — 387 Total deferred tax liabilities 13,889 9,499 Deferred income tax liability, net $ (5,826 ) $ (5,113 )
Schedule of Components of Income Tax Expense (Benefit) [Table Text Block]	Our income tax (expense) benefit for the years ended December 31, 2015, 2014 and 2013 is as follows: Years Ended December 31, 2015 2014 2013 Current income tax benefit (expense) $ — $ (10 ) $ — Deferred income tax benefit (expense) (1,134 ) (547 ) 495 Effective income tax rate 0.9 % 0.6 % 1.6 %
Schedule of Effective Income Tax Rate Reconciliation [Table Text Block]	A reconciliation of our expected income tax (expense) benefit calculated at the U.S. federal statutory rate of 34% to our actual tax (expense) for the years ended December 31, 2015, 2014 and 2013 is as follows: Years Ended December 31, 2015 2014 2013 Net loss before income tax benefit (expense) $ (126,241 ) $ (96,638 ) $ (31,488 ) US Federal statutory tax rate 34 % 34 % 34 % Federal income tax benefit at statutory rate 42,922 32,857 10,706 Reconciling items: Partnership loss not subject to income tax (43,812 ) (33,216 ) (10,296 ) Income not subject to corporate-level tax — — 222 State and local tax benefit (expense) (103 ) (159 ) 71 Other (141 ) (39 ) (208 ) Income tax benefit (expense) $ (1,134 ) $ (557 ) $ 495

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2015
Commitments and Contingencies Disclosure [Abstract]
Future non-cancelable commitments related to certain contractual obligations	Future non-cancelable commitments related to the following contractual obligations as of December 31, 2015 , are presented below (in thousands): Operating leases and service contracts Asset Retirement Obligation Total 2016 $ 3,721 $ 6,822 $ 10,543 2017 2,286 — 2,286 2018 1,173 — 1,173 2019 1,345 — 1,345 2020 1,006 — 1,006 Thereafter 1,537 28,549 30,086 $ 11,068 $ 35,371 $ 46,439
Total expenses related to operating leases, asset retirement obligations, land site leases and right-of-way agreements	The following table presents activity in the Partnership's asset retirement obligations (in thousands): Years Ended December 31, 2015 2014 Beginning asset retirement obligation $ 34,645 $ 34,636 Liabilities assumed — 248 Expenditures (91 ) (1,030 ) Accretion expense 817 791 Total ending asset retirement obligation 35,371 34,645 Less: current portion 6,822 — Long-term asset retirement obligation $ 28,549 $ 34,645

Reporting Segments (Tables)

Reporting Segments (Tables)	12 Months Ended
	Dec. 31, 2015
Segment Reporting [Abstract]
Segment information for the periods	The following tables set forth our segment information for the periods indicated (in thousands): Year Ended December 31, 2015 Gathering and Processing Transmission Terminals Total Revenue $ 173,597 $ 43,682 $ 17,755 $ 235,034 Gain (loss) on commodity derivatives, net 1,324 — — 1,324 Total revenue 174,921 43,682 17,755 236,358 Operating expenses: Purchases of natural gas, NGL's and condensate 97,580 8,303 — 105,883 Direct operating expenses 39,189 13,720 6,640 59,549 Selling, general and administrative expenses 27,232 Equity compensation expense 3,774 Depreciation, amortization and accretion expense 38,014 Total operating expenses 234,452 Gain (loss) on sale of assets, net (3,011 ) Loss on impairment of goodwill (118,592 ) Interest expense (14,745 ) Earnings in unconsolidated affiliates 8,201 Income tax (expense) benefit (1,134 ) Income (loss) from discontinued operations, net of tax (80 ) Net income (loss) (127,455 ) Less: Net income (loss) attributable to noncontrolling interests 25 Net income (loss) attributable to the Partnership $ (127,480 ) Segment gross margin (a) $ 76,865 $ 35,301 $ 11,115 $ 123,281 Year Ended December 31, 2014 Gathering and Processing Transmission Terminals Total Revenue $ 203,616 $ 88,189 $ 15,504 $ 307,309 Gain (loss) on commodity derivatives, net 1,091 — — 1,091 Total revenue 204,707 88,189 15,504 308,400 Operating expenses: Purchases of natural gas, NGL's and condensate 152,690 45,262 — 197,952 Direct operating expenses 23,783 15,577 6,342 45,702 Selling, general and administrative expenses 23,103 Equity compensation expense 1,536 Depreciation, amortization and accretion expense 28,832 Total operating expenses 297,125 Gain (loss) on sale of assets, net (122 ) Loss on impairment of property, plant and equipment (99,892 ) Interest expense (7,577 ) Other income (expense) (670 ) Earnings in unconsolidated affiliates 348 Income tax (expense) benefit (557 ) Income (loss) from discontinued operations, net of tax (611 ) Net income (loss) (97,806 ) Less: Net income (loss) attributable to noncontrolling interests 214 Net income (loss) attributable to the Partnership $ (98,020 ) Segment gross margin (a) $ 50,817 $ 42,828 $ 9,162 $ 102,807 Year Ended December 31, 2013 Gathering and Processing Transmission Terminals (b) Total Revenue $ 205,179 $ 79,041 $ 9,831 $ 294,051 Gain (loss) on commodity derivatives, net 28 — — 28 Total revenue 205,207 79,041 9,831 294,079 Operating expenses: Purchases of natural gas, NGL's and condensate 168,574 46,479 — 215,053 Direct operating expenses 14,574 13,259 4,403 32,236 Selling, general and administrative expenses 19,079 Equity compensation expense 2,094 Depreciation, amortization and accretion expense 30,002 Total operating expenses 298,464 Gain (loss) on involuntary conversion of property, plant and equipment 343 Loss on impairment of property, plant and equipment (18,155 ) Interest expense (9,291 ) Income tax (expense) benefit 495 Income (loss) from discontinued operations, net of tax (2,413 ) Net income (loss) (33,406 ) Less: Net income (loss) attributable to noncontrolling interests 633 Net income (loss) attributable to the Partnership $ (34,039 ) Segment gross margin (a) $ 36,985 $ 32,408 $ 5,428 $ 74,821 December 31, 2015 2014 Segment assets: Gathering and Processing $ 572,824 $ 686,395 Transmission 133,870 132,767 Terminals 84,449 68,094 Other (c) 100,153 26,302 Total assets $ 891,296 $ 913,558 (a) Segment gross margin for our Gathering and Processing segment consists of revenue less purchases of natural gas, NGLs and condensate and COMA. Segment gross margin for our Transmission segment consists of revenue, less purchases of natural gas and COMA. Segment gross margin for our Terminals segment consists of revenue, less direct operating expenses. Gross margin consists of the sum of the segment gross margin amounts for each of these segments. As an indicator of our operating performance, gross margin should not be considered an alternative to, or more meaningful than, net income or cash flow from operations as determined in accordance with GAAP. Our gross margin may not be comparable to a similarly titled measure of another company because other entities may not calculate gross margin in the same manner. (b) Terminals segment amounts are for the period from April 15, 2013 to December 31, 2013. (c) Other assets not allocable to segments consist of investment in unconsolidated affiliate, corporate leasehold improvements, and other assets. For a definition of gross margin and a reconciliation to its most directly comparable financial measure calculated and presented in accordance with GAAP and a discussion of how we use gross margin to evaluate our operating performance, please read Item 7. "Management's Discussion and Analysis, How We Evaluate Our Operations."
Percentage of revenue earned from major customers	The following table summarizes those customers who accounted for more than 10% of the Partnership's consolidated revenue for the each of the last three years: Years Ended December 31, 2015 2014 2013 Customer A 10 % 22 % 28 % Customer B — % — % 13 % Customer C — % 12 % 12 % Customer D — % 10 % 10 % Other 90 % 56 % 37 % Total 100 % 100 % 100 % The following table summarizes the percentage of revenue earned from those customers in each segment that exceed 10% of the Partnership's consolidated segment's revenue for the each of the periods presented below: Years Ended December 31, 2015 2014 2013 Gathering and Processing: Customer A 12 % 33 % 43 % Customer B — % 12 % 19 % Customer J 12 % — % — % Other 76 % 55 % 38 % Total 100 % 100 % 100 % Transmission: Customer C — % 43 % 39 % Customer D 16 % 16 % 16 % Customer K 19 % — % — % Other 65 % 41 % 45 % Total 100 % 100 % 100 % Terminals: Customer F 13 % 19 % 20 % Customer B 13 % 20 % 17 % Customer G 21 % 15 % 16 % Customer H — % 11 % 13 % Customer I 13 % — % — % Other 40 % 35 % 34 % Total 100 % 100 % 100 %

Quarterly Financial Data (Table

Quarterly Financial Data (Tables)	12 Months Ended
	Dec. 31, 2015
Quarterly Financial Information Disclosure [Abstract]
Schedule of Quarterly Financial Information [Table Text Block]	Summarized unaudited quarterly financial data for 2015 and 2014 are as follows (in thousands, except per unit amounts): First Quarter Second Quarter Third Quarter Fourth Quarter (b) Year Ended December 31, 2015 Total revenues $ 64,609 $ 67,509 $ 55,641 $ 48,599 Gross margin (a) 33,776 32,304 29,134 28,067 Operating income (loss) 3,434 1,867 (1,523 ) (123,475 ) Net income (loss) from continuing operations 835 (2,002 ) (4,574 ) (121,634 ) Income (loss) from discontinued operations, net of tax 5 (31 ) (53 ) (1 ) Net income (loss) attributable to noncontrolling interest 14 32 34 (55 ) Net income (loss) attributable to the Partnership 826 (2,065 ) (4,661 ) (121,580 ) General Partner's Interest in net income (loss) 10 (25 ) (60 ) (1,570 ) Limited Partners' Interest in net income (loss) $ 816 $ (2,040 ) $ (4,601 ) $ (120,010 ) Limited Partners' income (loss) per unit: Income (loss) from continuing operations $ (0.19 ) $ (0.35 ) $ (0.48 ) $ (4.16 ) Income (loss) from discontinued operations — — — — Net income (loss) $ (0.19 ) $ (0.35 ) $ (0.48 ) $ (4.16 ) Year Ended December 31, 2014 Total revenues $ 80,238 $ 77,680 $ 70,305 $ 80,177 Gross margin (a) 23,081 22,167 21,332 36,227 Operating income (loss) 2,450 734 (290 ) (91,633 ) Net income (loss) from continuing operations 558 (1,095 ) (2,397 ) (94,261 ) Income (loss) from discontinued operations, net of tax (50 ) (506 ) (26 ) (29 ) Net income (loss) attributable to noncontrolling interest 108 66 33 7 Net income (loss) attributable to the Partnership 400 (1,667 ) (2,456 ) (94,297 ) General Partner's Interest in net income (loss) 7 (22 ) (32 ) (1,232 ) Limited Partners' Interest in net income (loss) $ 393 $ (1,645 ) $ (2,424 ) $ (93,065 ) Limited Partners' income (loss) per unit: Income (loss) from continuing operations $ (0.31 ) $ (0.55 ) $ (0.58 ) $ (4.98 ) Income (loss) from discontinued operations (0.01 ) (0.04 ) — — Net income (loss) $ (0.32 ) $ (0.59 ) $ (0.58 ) $ (4.98 ) (a) For a definition of gross margin and a reconciliation to its most directly comparable financial measure calculated and presented in accordance with GAAP and a discussion of how we use gross margin to evaluate our operating performance, please read Item 7. "Management's Discussion and Analysis, How We Evaluate Our Operations." (b) In the fourth quarter of 2015, we recognized a Loss on impairment of goodwill of $118.6 million . In the fourth quarter of 2014, we recognized a Loss on impairment of property, plant and equipment of $99.9 million .

Organization and Basis of Pre51

Organization and Basis of Presentation (Details) mi in Thousands, bbl in Millions	12 Months Ended
	Dec. 31, 2015facilitypipelinebillion_cubic_feet_per_daygathering_systemmibbl	Aug. 11, 2014
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
General Partners' Capital Account, Percentage	95.00%
Limited Partners' Capital Account, Percentage	5.00%
Number of Gathering Systems | gathering_system	12
Number of Processing Facilities | facility	5
Number of Fractionation Facilities | facility	3
Number of Marine Terminal Sites | facility	3
Number of Interstate Pipelines | pipeline	3
Number of Intrastate Pipelines | pipeline	5
Number of Oil Pipelines | pipeline	1
Gathering pipeline (miles) | mi	3
Volume of Natural Gas, Operating | billion_cubic_feet_per_day	1
Million barrels of storage capacity | bbl	1.8
Noncontrolling interest, ownership percentage by noncontrolling owners	7.80%
Burns Point Plant [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Acquired interest (percent)	50.00%
Minimum [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Useful life	10 years
Maximum [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Useful life	30 years
MPOG [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Ownership percentage	66.70%	66.70%
Mesquite [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Ownership percentage	46.00%
Delta House [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Ownership percentage	12.90%

Acquisitions (Consideration Tra

Acquisitions (Consideration Transferred) (Details) - Costar Midstream, L.L.C. [Member] - USD ($) $ in Thousands	Oct. 14, 2014	Dec. 31, 2015	Dec. 31, 2014
Business Acquisition [Line Items]
Cash	$ 258,001
Limited partner common units	147,296	$ 0	$ 147,296
Total fair value of consideration	$ 405,297

Acquisitions Fair Value of Iden

Acquisitions Fair Value of Identifiable Assets and Consideration Transferred (Details) - USD ($) $ in Thousands	Oct. 14, 2014	Jan. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Apr. 15, 2013
Business Acquisition [Line Items]
Goodwill			$ 16,262	$ 142,236
Property, plant and equipment			648,013	582,182
Asset retirement cost			35,371	34,645	$ 34,636
Accounts payable			4,667	20,326
Accrued gas purchases			7,281	14,326
Asset retirement obligations			$ 6,822	$ 0
Costar Midstream, L.L.C. [Member]
Business Acquisition [Line Items]
Working capital	$ 8,152
Processing plants	48,357
Pipelines	128,799
Land	1,244
Buildings	682
Equipment	9,827
Construction in progress	16,146
Total property, plant and equipment	205,055
Investment in unconsolidated affiliate	11,884
Customer relationships	53,400
Dedicated acreage	32,000
Noncontrolling interest	(219)
Goodwill	95,025
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Less Noncontrolling Interest	405,297
Cash	$ 258,001
Lavaca [Member]
Business Acquisition [Line Items]
Land		$ 2
Equipment		753
Total property, plant and equipment		59,492
Goodwill		23,567
Intangible assets		21,350
Cash		104,409
High Point [Member]
Business Acquisition [Line Items]
Total identifiable net assets						$ 61,900
Pipelines [Member] | Lavaca [Member]
Business Acquisition [Line Items]
Total property, plant and equipment		$ 58,737

Acquisitions (Pro Forma Informa

Acquisitions (Pro Forma Information) (Details) - Costar Midstream, L.L.C. [Member] - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Business Acquisition [Line Items]
Revenue	$ 435,133	$ 448,748
Net loss	$ (101,237)	$ (30,672)
Limited partners' net loss per unit	$ (6.15)	$ (3.82)

Acquisitions Narrative (Details

Acquisitions Narrative (Details) $ / shares in Units, bbl in Millions	Feb. 12, 2016USD ($)shares	Oct. 08, 2015USD ($)shares	Sep. 18, 2015USD ($)	Sep. 10, 2015USD ($)shares	Jun. 01, 2015USD ($)	Mar. 31, 2015USD ($)	Oct. 14, 2014USD ($)shares	Jan. 31, 2014USD ($)mishares	Jan. 29, 2014USD ($)shares	Dec. 17, 2013USD ($)sharesbbl	Apr. 15, 2013USD ($)$ / shares	Aug. 14, 2014USD ($)	Dec. 31, 2015USD ($)$ / unitsharesbbl	Sep. 30, 2015USD ($)	Jun. 30, 2015USD ($)	Mar. 31, 2015USD ($)	Dec. 31, 2014USD ($)shares	Sep. 30, 2014USD ($)	Jun. 30, 2014USD ($)	Mar. 31, 2014USD ($)	Sep. 30, 2013USD ($)	Jun. 30, 2013USD ($)	Apr. 15, 2013USD ($)	Jun. 30, 2015Gas_Receipt_Pointmi	Sep. 30, 2015USD ($)	Dec. 31, 2015USD ($)misharesbbl	Dec. 31, 2014USD ($)$ / unitshares	Dec. 31, 2013USD ($)shares	Sep. 15, 2015shares	Sep. 14, 2015USD ($)	Aug. 20, 2014shares	Aug. 11, 2014	Dec. 11, 2013shares
Business Acquisition [Line Items]
Property, plant and equipment													$ 648,013,000				$ 582,182,000									$ 648,013,000	$ 582,182,000
Loss on sale of assets																										(150,000)	(87,000)	$ (75,000)
Proceeds from sale of property, plant, and equipment																										$ 4,813,000	6,323,000	500,000
Noncontrolling interest, ownership percentage by noncontrolling owners													7.80%													7.80%
Partners' Capital Account, Distributions to Existing Interest																										$ 0	0	$ 15,612,000
Discount rate																	9.50%									10.00%		10.00%
Acquisition Working Capital Adjustment																										$ 7,400,000
Revenues													$ 48,599,000	$ 55,641,000	$ 67,509,000	$ 64,609,000	$ 80,177,000	$ 70,305,000	$ 77,680,000	$ 80,238,000						236,358,000	308,400,000	$ 294,079,000
Net income (loss)													(121,580,000)	(4,661,000)	(2,065,000)	826,000	(94,297,000)	(2,456,000)	(1,667,000)	400,000						(127,480,000)	(98,020,000)	(34,039,000)
Operating income (loss)													$ (123,475,000)	$ (1,523,000)	$ 1,867,000	$ 3,434,000	(91,633,000)	$ (290,000)	$ 734,000	2,450,000						$ (119,697,000)	(88,739,000)	(22,197,000)
Transaction costs																	$ 100,000										100,000
Length Of Pipeline | mi																										3,000
Issuance of common units, net of offering costs		$ 1,700,000		$ 81,000,000					$ 86,900,000																		$ 119,300,000	$ 54,900,000
Limited partners, units issued | shares		151,937		7,500,000					3,400,000				30,427,000				22,670,000									30,427,000	22,670,000	7,414,000	7,500,000		4,622,352		2,568,712
Loss on impairment of goodwill																										$ 118,592,000	$ 0	$ 0
Finite-lived intangible assets, amortization expense, next twelve months													$ 4,300,000													4,300,000
Payments to acquire equity method investments																										71,597,000	12,000,000	0
Earnings in unconsolidated affiliates																										8,201,000	348,000	0
Distributions from unconsolidated affiliates																										8,201,000	348,000	0
Proceeds from equity method investement, return of capital																										$ 12,367,000	1,632,000	0
Million barrels of storage capacity | bbl													1.8													1.8
Distributions																										$ 53,386,000	28,009,000	16,120,000
Payments on long-term debt																										189,150,000	250,870,000	131,571,000
Series A convertible preferred units											$ 90,000,000		$ 169,712,000				$ 107,965,000						$ 90,000,000			169,712,000	107,965,000
Loss on impairment of property, plant and equipment																	99,900,000					$ 15,200,000				0	99,892,000	18,155,000
Property plant and equipment gross													$ 793,976,000				698,017,000									793,976,000	698,017,000
Payments to Acquire Interest in Subsidiaries and Affiliates																										65,703,000	23,884,000
Series B
Business Acquisition [Line Items]
Limited partners, units issued | shares								1,168,225
Distributions																										1,373,000	2,220,000	0
Costar Midstream, L.L.C. [Member]
Business Acquisition [Line Items]
Acquired interest (percent)							100.00%
Cash							$ 258,001,000
Equity interests issued (in units) | shares							6,900,000
Limited partner common units							$ 147,296,000																			0	147,296,000
Working capital, accounts receivable							11,200,000
Revenues																											19,900,000
Operating income (loss)																											300,000
Transaction costs																	$ 500,000										500,000
Loss on impairment of goodwill																										95,000,000
Total fair value of consideration							$ 405,297,000
Lavaca [Member]
Business Acquisition [Line Items]
Cash								$ 104,409,000
Discount rate								10.50%
Revenues																											16,800,000
Operating income (loss)																											7,600,000
Length Of Pipeline | mi								120
Useful life								25 years
Loss on impairment of goodwill																										$ 23,600,000
High Point [Member]
Business Acquisition [Line Items]
Acquired interest (percent)											100.00%												100.00%
Total identifiable net assets											$ 61,900,000												$ 61,900,000
Revenues																					$ 30,400,000
Net income (loss)																					$ 7,200,000
Length Of Pipeline | mi																								700
Total Consideration for Issuance of Preferred Units											15,000,000												15,000,000
Williams [Member]
Business Acquisition [Line Items]
Total Consideration																				6,500,000
Minimum [Member]
Business Acquisition [Line Items]
Useful life																										10 years
Minimum [Member] | Costar Midstream, L.L.C. [Member]
Business Acquisition [Line Items]
Discount rate							11.00%
Maximum [Member]
Business Acquisition [Line Items]
Useful life																										30 years
Maximum [Member] | Costar Midstream, L.L.C. [Member]
Business Acquisition [Line Items]
Discount rate							16.00%
General Partner [Member]
Business Acquisition [Line Items]
Partners' Capital Account, Distributions to Existing Interest																												(312,000)
Issuance of common units, net of offering costs																										$ 0
Distributions																										7,023,000	2,913,000	623,000
Partners Capital Account Distributions, Delta House																										(96,297,000)
Blackwater [Member]
Business Acquisition [Line Items]
Distributions																										(500,000)
Partners Capital Account Distributions, Delta House																										27,700,000
Total Partners Capital
Business Acquisition [Line Items]
Partners' Capital Account, Distributions to Existing Interest											15,600,000																	(15,612,000)
Net income (loss)																										(127,480,000)	(98,020,000)	(34,039,000)
Issuance of common units, net of offering costs																											351,551,000
Distributions																										71,737,000	42,063,000	22,251,000
Total Partners Capital | Series B
Business Acquisition [Line Items]
Issuance of Series B Units																										1,373,000
Series B
Business Acquisition [Line Items]
Issuance of common units, net of offering costs																										0
Series B | Series B
Business Acquisition [Line Items]
Issuance of Series B Units								$ 30,000,000																		$ 1,373,000	32,220,000
Pinto Offshore Holdings LLC [Member]
Business Acquisition [Line Items]
Ownership percentage			26.30%
Delta House FPS LLC [Member]
Business Acquisition [Line Items]
Ownership percentage			49.00%
Delta House Oil and Gas Lateral LLC [Member]
Business Acquisition [Line Items]
Ownership percentage			49.00%
Delta House [Member]
Business Acquisition [Line Items]
Ownership percentage													12.90%													12.90%
Payments to acquire equity method investments			$ 162,000,000
Earnings in unconsolidated affiliates																										$ 7,470,000	0
Distributions from unconsolidated affiliates																										16,600,000
Payments to Acquire Interest in Subsidiaries and Affiliates																										$ 65,703,000	0
MPOG [Member]
Business Acquisition [Line Items]
Ownership percentage													66.70%													66.70%						66.70%
Payments to acquire equity method investments												$ 12,000,000
Earnings in unconsolidated affiliates																										$ 731,000	348,000
Distributions from unconsolidated affiliates																										3,900,000	2,000,000
Payments to Acquire Interest in Subsidiaries and Affiliates																										0	12,000,000
Terminals [Member]
Business Acquisition [Line Items]
Revenues																										$ 17,755,000	$ 15,504,000	9,831,000
Operating income (loss)																												800,000
Million barrels of storage capacity | bbl										1.3
ArcLight [Member] | High Point [Member]
Business Acquisition [Line Items]
Number of natural gas collection receipt points | Gas_Receipt_Point																								75
Blackwater [Member]
Business Acquisition [Line Items]
Limited partner common units																				3,100,000
Total identifiable net assets											$ 22,700,000												22,700,000
Total fair value of consideration										$ 63,900,000
Distributions																				27,700,000								27,650,000
Units issued in business acquisition | shares										125,500
Blackwater [Member] | General Partner [Member]
Business Acquisition [Line Items]
Distributions																												30,702,000
Series A
Business Acquisition [Line Items]
Discount rate											18.00%
Distribution made to member or limited partner, distributions paid, conversion price per unit | $ / shares											$ 17.50
Distribution growth rate																										1.00%
Fair value input, option value | $ / unit													0.07														9.68
Issuance of Preferred Units [Member] | High Point [Member] | Series A
Business Acquisition [Line Items]
Contributed capital											$ 5,142,857												5,142,857
Transaction expenses																							$ 2,500,000
Revolving Credit Facility [Member] | Fourth Amendment [Member] | Series A
Business Acquisition [Line Items]
Payments on long-term debt											$ 12,500,000
AIM Midstream Holdings [Member] | High Point [Member] | Partnership Interest [Member]
Business Acquisition [Line Items]
Partnership cancellation of subordinated units (percent)											90.00%
Salisbury [Member]
Business Acquisition [Line Items]
Property, plant and equipment																														$ 900,000
Loss on sale of assets																									$ 100,000
Eloi Bay [Member]
Business Acquisition [Line Items]
Property, plant and equipment					$ 3,000,000
Gain (Loss) on Disposition of Property Plant Equipment					$ 3,000,000
Madison [Member]
Business Acquisition [Line Items]
Proceeds from sale of property, plant, and equipment						$ 6,100,000
Loss on impairment of property, plant and equipment																				$ 3,000,000
Property plant and equipment gross																												$ 6,100,000
MPOG [Member]
Business Acquisition [Line Items]
Earnings in unconsolidated affiliates																										$ 700,000	$ 300,000
Subsequent Event [Member] | Interest Rate Swap [Member]
Business Acquisition [Line Items]
EscrowedUnitsReturnedtoPartnership | shares	1,034,483
Payments for Previous Acquisition	$ 300,000

Discontinued Operations (Detail

Discontinued Operations (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Revenue									$ 74	$ 474	$ 2,084
Expense									(196)	(658)	(2,361)
Impairment									0	(673)	(2,400)
Loss on sale of assets									(150)	(87)	(75)
Income tax benefit									192	333	339
Income (loss) from discontinued operations, net of tax	$ (1)	$ (53)	$ (31)	$ 5	$ (29)	$ (26)	$ (506)	$ (50)	$ (80)	$ (611)	$ (2,413)
Limited Partners' net income (loss) from discontinued operations per unit (basic and diluted)	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ (0.04)	$ (0.01)	$ 0	$ (0.04)	$ (0.27)
Loss on impairment of noncurrent assets held for sale									$ 0	$ 673	$ 2,400
Discount rate					9.50%				10.00%		10.00%
Gathering And Processing [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Loss on impairment of noncurrent assets held for sale											$ 1,800
Terminals [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Loss on impairment of noncurrent assets held for sale											$ 600

Concentration of Credit Risk 57

Concentration of Credit Risk and Trade Accounts Receivable (Details)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Revenue, Major Customer
Entity-wide revenue by major customer, percentage	100.00%	100.00%	100.00%
Customer A [Member]
Revenue, Major Customer
Entity-wide revenue by major customer, percentage	10.00%	22.00%	28.00%
Customer B [Member]
Revenue, Major Customer
Entity-wide revenue by major customer, percentage	0.00%	0.00%	13.00%
Customer C [Member]
Revenue, Major Customer
Entity-wide revenue by major customer, percentage	0.00%	12.00%	12.00%
Customer D [Member]
Revenue, Major Customer
Entity-wide revenue by major customer, percentage	0.00%	10.00%	10.00%
Customer Other [Member]
Revenue, Major Customer
Entity-wide revenue by major customer, percentage	90.00%	56.00%	37.00%

Other Current Assets (Details)

Other Current Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Other Current Assets [Abstract]
Prepaid insurance—current portion	$ 3,948	$ 4,162
Restricted cash	0	6,475
Other prepaid amounts	2,866	758
Other current assets	3,280	4,159
Other current assets	$ 10,094	$ 15,554

Derivatives (Fair Value of Comm

Derivatives (Fair Value of Commodity Derivatives) (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Derivative [Line Items]
Derivative Asset, Fair Value, Net	$ 365	$ 688
Derivative Liability, Fair Value, Net	0	(215)
Commodity derivatives [Member]
Derivative [Line Items]
Derivative asset, gross derivative asset	365	688
Derivative asset, gross derivative liabilities	0	0
Derivative liability, gross derivative assets	0	0
Derivative liability, gross derivative liabilities	0	(215)
Commodity derivatives [Member] | Risk Management Assets [Member]
Derivative [Line Items]
Derivative asset, gross derivative asset	365	688
Derivative asset, gross derivative liabilities	0	0
Derivative Asset, Fair Value, Net	365	688
Commodity derivatives [Member] | Risk Management Assets - Long Term [Member]
Derivative [Line Items]
Derivative asset, gross derivative asset	0	0
Derivative asset, gross derivative liabilities	0	0
Derivative Asset, Fair Value, Net	0	0
Commodity derivatives [Member] | Risk Management Liabilities [Member]
Derivative [Line Items]
Derivative liability, gross derivative assets	0	0
Derivative liability, gross derivative liabilities	0	(215)
Derivative Liability, Fair Value, Net	0	(215)
Commodity derivatives [Member] | Risk Management Liabilities - Long Term [Member]
Derivative [Line Items]
Derivative liability, gross derivative assets	0	0
Derivative liability, gross derivative liabilities	0	0
Derivative Liability, Fair Value, Net	$ 0	$ 0

Derivatives (Realized and Unrea

Derivatives (Realized and Unrealized Gains (Losses)) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Derivatives, Fair Value [Line Items]
Gain (loss) on commodity derivatives, net	$ 1,324	$ 1,091	$ 28
Commodity derivatives [Member]
Derivatives, Fair Value [Line Items]
Gain (loss) on commodity derivatives, net	457	(733)	200
Gain (loss) on derivatives, unrealized	(71)	595	(1,495)
Commodity derivatives [Member] | Gain (Loss) on Derivative Instruments [Member]
Derivatives, Fair Value [Line Items]
Gain (loss) on commodity derivatives, net	1,610	735	1,069
Gain (loss) on derivatives, unrealized	(286)	356	(1,041)
Commodity derivatives [Member] | Interest Expense [Member]
Derivatives, Fair Value [Line Items]
Gain (loss) on commodity derivatives, net	(240)	(433)	(207)
Gain (loss) on derivatives, unrealized	215	239	(454)
Commodity derivatives [Member] | Other Income [Member]
Derivatives, Fair Value [Line Items]
Gain (loss) on commodity derivatives, net	(913)	(1,035)	(662)
Gain (loss) on derivatives, unrealized	$ 0	$ 0	$ 0

Derivatives (Details Textual)

Derivatives (Details Textual) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Mar. 02, 2016	Aug. 01, 2015
Derivative [Line Items]
Amortization of weather derivative premium	$ 912,000	$ 1,035,000	$ 662,000
Interest Rate Swap [Member]
Derivative [Line Items]
Notional amount of interest rate derivatives					$ 100,000,000
Weather Contract [Member]
Derivative [Line Items]
Derivative instruments not designated as hedging instruments, potential cash proceeds from Contract	10,000,000
Derivative instruments not designated as hedging instruments, asset, at fair value	0
Payments of derivative issuance costs	$ 900,000	1,000,000
Term of Contract	1 year
Amortization of weather derivative premium	$ 400,000	$ 400,000
Subsequent Event [Member] | Interest Rate Swap [Member]
Derivative [Line Items]
Notional amount of interest rate derivatives				$ 200,000,000

Fair Value Measurement (Fair Va

Fair Value Measurement (Fair Value of Financial Instruments) (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Commodity Contract [Member]
Quantitative Information about Level 3 Fair Value Measurements
Estimated Fair Value	$ 0	$ 286
Interest Rate Swap [Member]
Quantitative Information about Level 3 Fair Value Measurements
Estimated Fair Value	0	(215)
Estimate of Fair Value Measurement [Member] | Commodity Contract [Member]
Quantitative Information about Level 3 Fair Value Measurements
Estimated Fair Value	0	286
Estimate of Fair Value Measurement [Member] | Commodity Contract [Member] | Level 1 [Member]
Quantitative Information about Level 3 Fair Value Measurements
Estimated Fair Value	0	0
Estimate of Fair Value Measurement [Member] | Commodity Contract [Member] | Level 2 [Member]
Quantitative Information about Level 3 Fair Value Measurements
Estimated Fair Value	0	286
Estimate of Fair Value Measurement [Member] | Commodity Contract [Member] | Level 3 [Member]
Quantitative Information about Level 3 Fair Value Measurements
Estimated Fair Value	0	0
Estimate of Fair Value Measurement [Member] | Interest Rate Swap [Member]
Quantitative Information about Level 3 Fair Value Measurements
Estimated Fair Value	0	(215)
Estimate of Fair Value Measurement [Member] | Interest Rate Swap [Member] | Level 1 [Member]
Quantitative Information about Level 3 Fair Value Measurements
Estimated Fair Value	0	0
Estimate of Fair Value Measurement [Member] | Interest Rate Swap [Member] | Level 2 [Member]
Quantitative Information about Level 3 Fair Value Measurements
Estimated Fair Value	0	(215)
Estimate of Fair Value Measurement [Member] | Interest Rate Swap [Member] | Level 3 [Member]
Quantitative Information about Level 3 Fair Value Measurements
Estimated Fair Value	$ 0	$ 0

Fair Value Measurement (Details

Fair Value Measurement (Details Textual)	12 Months Ended
	Dec. 31, 2015USD ($)
Fair Value Disclosures [Abstract]
Transfers out of Level 3	$ 0

Property, Plant and Equipment64

Property, Plant and Equipment, Net (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Property, Plant and Equipment [Line Items]
Loss on impairment of noncurrent assets held for sale	$ 0	$ 673	$ 2,400
Property, Plant and Equipment, Net [Abstract]
Property plant and equipment gross	793,976	698,017
Accumulated depreciation	(145,963)	(115,835)
Property, plant and equipment, net	648,013	582,182
Interest Costs Capitalized	1,900	800	200
Depreciation	31,900	23,900	25,900
Land [Member]
Property, Plant and Equipment, Net [Abstract]
Property plant and equipment gross	5,282	5,282
Construction in progress [Member]
Property, Plant and Equipment, Net [Abstract]
Property plant and equipment gross	46,045	77,550
Buildings and improvements [Member]
Property, Plant and Equipment, Net [Abstract]
Property plant and equipment gross	9,864	6,855
Processing and treating plants [Member]
Property, Plant and Equipment, Net [Abstract]
Property plant and equipment gross	97,784	80,837
Pipelines [Member]
Property, Plant and Equipment, Net [Abstract]
Property plant and equipment gross	554,400	476,997
Equipment [Member]
Property, Plant and Equipment, Net [Abstract]
Property plant and equipment gross	22,207	12,345
Tanks, truck rack and piping [Member]
Property, Plant and Equipment, Net [Abstract]
Property plant and equipment gross	$ 58,394	38,151
Minimum [Member] | Buildings and improvements [Member]
Property, Plant and Equipment, Net [Abstract]
Useful Life (in years)	4 years
Minimum [Member] | Processing and treating plants [Member]
Property, Plant and Equipment, Net [Abstract]
Useful Life (in years)	8 years
Minimum [Member] | Pipelines [Member]
Property, Plant and Equipment, Net [Abstract]
Useful Life (in years)	3 years
Minimum [Member] | Equipment [Member]
Property, Plant and Equipment, Net [Abstract]
Useful Life (in years)	5 years
Minimum [Member] | Tanks, truck rack and piping [Member]
Property, Plant and Equipment, Net [Abstract]
Useful Life (in years)	20 years
Maximum [Member] | Buildings and improvements [Member]
Property, Plant and Equipment, Net [Abstract]
Useful Life (in years)	40 years
Maximum [Member] | Processing and treating plants [Member]
Property, Plant and Equipment, Net [Abstract]
Useful Life (in years)	40 years
Maximum [Member] | Pipelines [Member]
Property, Plant and Equipment, Net [Abstract]
Useful Life (in years)	40 years
Maximum [Member] | Equipment [Member]
Property, Plant and Equipment, Net [Abstract]
Useful Life (in years)	20 years
Maximum [Member] | Tanks, truck rack and piping [Member]
Property, Plant and Equipment, Net [Abstract]
Useful Life (in years)	40 years
Ala Tenn System [Member]
Property, Plant and Equipment, Net [Abstract]
Property plant and equipment gross	$ 111,900	$ 101,900
Gathering And Processing [Member]
Property, Plant and Equipment [Line Items]
Loss on impairment of noncurrent assets held for sale			$ 1,800

Property, Plant and Equipment65

Property, Plant and Equipment, Net (Asset Impairments and Insurance Proceeds) (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Dec. 31, 2014	Jun. 30, 2013	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Property, Plant and Equipment [Line Items]
Loss on impairment of property, plant and equipment	$ 99,900	$ 15,200	$ 0	$ 99,892	$ 18,155
Discount rate	9.50%		10.00%		10.00%
Impairment of long lived assets			$ 0	673	$ 2,400
Insurance proceeds from involuntary conversion of property, plant and equipment			0	0	482
Gain (loss) on involuntary conversion of property, plant and equipment			$ 0	$ 0	$ 343
Fair Value, Inputs, Level 3 [Member] | Income Approach Valuation Technique [Member]
Property, Plant and Equipment [Line Items]
Throughput volume decline rate					2.50%
Gathering And Processing [Member]
Property, Plant and Equipment [Line Items]
Impairment of long lived assets					$ 1,800

Goodwill and Intangible asset66

Goodwill and Intangible assets (Details) - USD ($) $ in Thousands	Jan. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Oct. 14, 2014
Goodwill [Line Items]
Goodwill, Impairment Loss		$ (118,592)	$ 0	$ 0
Goodwill		16,262	142,236
Amortization of Intangible Assets		5,300	4,100	$ 3,700
Finite-lived intangible assets, amortization expense, next twelve months		$ 4,300
Gathering And Processing [Member]
Goodwill [Line Items]
Goodwill			125,900
Terminals [Member]
Goodwill [Line Items]
Goodwill			$ 16,300
Minimum [Member]
Goodwill [Line Items]
Useful life		10 years
Maximum [Member]
Goodwill [Line Items]
Useful life		30 years
Lavaca [Member]
Goodwill [Line Items]
Goodwill, Impairment Loss		$ (23,600)
Goodwill	$ 23,567
Useful life	25 years
Costar Midstream, L.L.C. [Member]
Goodwill [Line Items]
Goodwill, Impairment Loss		$ (95,000)
Goodwill					$ 95,025

Goodwill and Intangible asset67

Goodwill and Intangible assets Schedule of intangible assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Finite-Lived Intangible Assets [Line Items]
Amortization of Intangible Assets	$ 5,300	$ 4,100	$ 3,700
Goodwill	16,262	142,236
Gross carrying amount	118,851	118,851
Accumulated amortization	(17,886)	(12,545)
Net carrying amount	100,965	106,306
Customer Contracts [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	12,101	12,101
Accumulated amortization	(12,101)	(11,110)
Net carrying amount	0	991
Customer Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	53,400	53,400
Accumulated amortization	(3,124)	(553)
Net carrying amount	50,276	52,847
Dedicated Acreage [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	53,350	53,350
Accumulated amortization	(2,661)	(882)
Net carrying amount	$ 50,689	52,468
Terminals [Member]
Finite-Lived Intangible Assets [Line Items]
Goodwill		16,300
Gathering And Processing [Member]
Finite-Lived Intangible Assets [Line Items]
Goodwill		$ 125,900

Investment in unconsolidated 68

Investment in unconsolidated affiliates (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Aug. 11, 2014
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Summarized Financial Information, Revenue	$ 37,724	$ 3,847	$ 0
Equity Method Investment, Summarized Financial Information, Current Assets	2,086	2,196
Equity Method Investments	82,301	22,252	0
Payments to Acquire Interest in Subsidiaries and Affiliates	65,703	23,884
Earnings in unconsolidated affiliates	8,201	348	0
Cash Dividends Paid to Parent Company by Unconsolidated Subsidiaries	(20,568)	(1,980)
Cash Call For Expansion Projects	6,713
Equity Method Investment, Summarized Financial Information, Noncurrent Assets	288,617	62,635
Equity Method Investment, Summarized Financial Information, Current Liabilities	366	398
Equity Method Investment, Summarized Financial Information, Noncurrent Liabilities	23,617	22,307
Equity Method Investment Summarized Financial Information Operating Expenses	3,375	1,722	0
Equity Method Investment, Summarized Financial Information, Net Income (Loss)	$ 29,437	510	0
MPOG [Member]
Schedule of Equity Method Investments [Line Items]
Ownership percentage	66.70%			66.70%
Equity Method Investments	$ 7,179	10,368	0
Payments to Acquire Interest in Subsidiaries and Affiliates	0	12,000
Earnings in unconsolidated affiliates	731	348
Cash Dividends Paid to Parent Company by Unconsolidated Subsidiaries	(3,920)	(1,980)
Cash Call For Expansion Projects	$ 0
Mesquite [Member]
Schedule of Equity Method Investments [Line Items]
Ownership percentage	46.00%
Equity Method Investments	$ 18,597	11,884	0
Payments to Acquire Interest in Subsidiaries and Affiliates	0	11,884
Earnings in unconsolidated affiliates	0	0
Cash Dividends Paid to Parent Company by Unconsolidated Subsidiaries	0	0
Cash Call For Expansion Projects	$ 6,713
Delta House [Member]
Schedule of Equity Method Investments [Line Items]
Ownership percentage	12.90%
Equity Method Investments	$ 56,525	0	$ 0
Payments to Acquire Interest in Subsidiaries and Affiliates	65,703	0
Earnings in unconsolidated affiliates	7,470	0
Cash Dividends Paid to Parent Company by Unconsolidated Subsidiaries	(16,648)	$ 0
Cash Call For Expansion Projects	$ 0

Accrued Expenses and Other Cu69

Accrued Expenses and Other Current Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Payables and Accruals [Abstract]
Current portion of asset retirement obligation	$ 6,822	$ 0
Accrued capital expenditures	3,984	17,134
Accrued expenses	3,178	4,560
Due to related parties	3,894	659
Gas imbalances payable	413	1,055
Other	6,744	2,392
Accrued expenses and other current liabilities	$ 25,035	$ 25,800

Asset Retirement Obligation (De

Asset Retirement Obligation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Asset Retirement Obligation Disclosure [Abstract]
Balance at beginning of period	$ 34,645	$ 34,636
Additions	0	248
Expenditures	(91)	(1,030)
Accretion expense	817	791
Balance at end of period	35,371	34,645
Current portion of asset retirement obligation	6,822	0
Asset Retirement Obligations, Noncurrent	28,549	$ 34,645
Restricted Cash and Cash Equivalents	$ 5,000

Debt Obligations (Outstanding B

Debt Obligations (Outstanding Borrowings) (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Debt Disclosure [Abstract]
Revolving credit facility	$ 525,100	$ 372,950
Other debt	2,338	2,908
Total debt	527,438	375,858
Less: current portion	2,338	2,908
Long-term debt	$ 525,100	$ 372,950

Debt Obligations (Textual) (Det

Debt Obligations (Textual) (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2015USD ($)	Dec. 31, 2014USD ($)	Dec. 31, 2013
Debt Instrument [Line Items]
Line of Credit Facility, Current Borrowing Capacity	$ 750,000
Line of Credit Facility, Maximum Borrowing Capacity Upon Increase	$ 900,000
Unused capacity, commitment fee percentage	0.50%
Ratio of indebtedness to net capital	4.56
Interest coverage ratio	8.56
Debt, weighted average interest rate	3.67%	3.80%	4.53%
Letters of credit outstanding amount	$ 1,800	$ 1,600
Revolving credit facility	525,100	$ 372,950
Proceeds from (payments for) other financing activities	3,000
Periodic payment	$ 300
Minimum [Member]
Debt Instrument [Line Items]
Interest coverage ratio	2.50
Maximum [Member]
Debt Instrument [Line Items]
Ratio of indebtedness to net capital	4.75
Ratio of indebtedness to net capital, after allowed acquisition	5.25
Federal Funds [Member]
Debt Instrument [Line Items]
Facility fee (percent)	0.50%
Eurodollar [Member]
Debt Instrument [Line Items]
Facility fee (percent)	1.00%
Insurance Premium Financing [Member]
Debt Instrument [Line Items]
Facility fee (percent)	3.95%
Fiscal Quarter Ending December 31, 2014 [Member] | Fourth Amendment [Member] | Base Rate [Member] | Minimum [Member]
Debt Instrument [Line Items]
Basis spread on variable rate	2.00%
Fiscal Quarter Ending December 31, 2014 [Member] | Fourth Amendment [Member] | Base Rate [Member] | Maximum [Member]
Debt Instrument [Line Items]
Basis spread on variable rate	3.25%
Fiscal Quarter Ending December 31, 2014 [Member] | Fourth Amendment [Member] | Eurodollar [Member] | Minimum [Member]
Debt Instrument [Line Items]
Basis spread on variable rate	1.00%
Fiscal Quarter Ending December 31, 2014 [Member] | Fourth Amendment [Member] | Eurodollar [Member] | Maximum [Member]
Debt Instrument [Line Items]
Basis spread on variable rate	2.25%

Partners' Capital (Units Outsta

Partners' Capital (Units Outstanding) (Details) - shares shares in Thousands	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Limited partner common units	30,427	22,670	7,414
General partner units	536	392	185
Series A
Preferred units outstanding	9,210	5,745	5,279
Series B
Preferred units outstanding	1,350	1,255	0

Partners Capital (Details Textu

Partners Capital (Details Textual)	Jan. 26, 2016$ / shares	Oct. 08, 2015USD ($)$ / sharesshares	Sep. 15, 2015$ / sharesshares	Sep. 10, 2015USD ($)$ / sharesshares	Oct. 14, 2014USD ($)	Jan. 29, 2014USD ($)$ / sharesshares	Apr. 15, 2013USD ($)$ / shares	Dec. 31, 2015USD ($)$ / shares$ / unitshares	Dec. 31, 2014shares	Jun. 30, 2014$ / shares	Apr. 15, 2013USD ($)	Dec. 31, 2015USD ($)$ / sharesshares	Dec. 31, 2014USD ($)$ / shares$ / unitshares	Dec. 31, 2013USD ($)$ / sharesshares	Feb. 12, 2016shares	Jul. 27, 2015USD ($)	Aug. 20, 2014$ / sharesshares	Feb. 05, 2014$ / sharesshares	Jan. 31, 2014shares	Dec. 11, 2013$ / sharesshares	Aug. 09, 2013shares
Subsidiary, Sale of Stock [Line Items]
Issuance of Series A Units												$ 44,768,000	$ 0	$ 14,393,000
Discount rate									9.50%			10.00%		10.00%
Accrued and paid-in-kind unitholder distribution for Series A Units														$ 4,811,000
General partner interest												1.30%
Limited partner interest												98.70%
Limited partners, units issued | shares		151,937	7,500,000	7,500,000		3,400,000		30,427,000	22,670,000			30,427,000	22,670,000	7,414,000			4,622,352			2,568,712
Payments on long-term debt												$ (189,150,000)	$ (250,870,000)	$ (131,571,000)
Incentive Distribution Right Allocation													100.00%
Class of Warrant or Right, Number of Securities Called by Warrants or Rights | shares																		300,000
Class of Warrant or Right, Exercise Price of Warrants or Rights | $ / shares																		$ 0.01
AggregateOfferingPrice								$ 100,000,000				$ 100,000,000
Sale of Stock, Price Per Share | $ / shares		$ 11.31		$ 11.31		$ 26.75											$ 25.8075			$ 22.47
Distribution declared per common unit (a) | $ / shares										$ 0.4625		$ 1.89	$ 1.85	$ 1.75
Issuance of common units, net of offering costs		$ 1,700,000		$ 81,000,000		$ 86,900,000							$ 119,300,000	$ 54,900,000
General Partners' Capital Account, Period Distribution Amount												$ 1,900,000	$ 5,700,000
General partners' interest units issued | shares								536,000	392,000			536,000	392,000	185,000
Investment Options, Exercise Price | $ / shares			$ 15.94
CallRightdefinedacquisitionvalue																$ 100,000,000
Series B
Subsidiary, Sale of Stock [Line Items]
Issuance of common units, net of offering costs												$ 0
Partners' Capital Account, Contributions												0
General Partner Interest
Subsidiary, Sale of Stock [Line Items]
Issuance of common units, net of offering costs												0
Partners' Capital Account, Contributions												$ 1,996,000	$ 5,678,000	$ 12,500,000
General partners' interest units issued | shares								143,517	206,810			143,517	206,810
General Partner Interest
Subsidiary, Sale of Stock [Line Items]
Incentive Distribution, Distribution Per Unit | $ / shares												$ 0.4125
Incentive Distribution Right Allocation														14.98%
Incentive Distribution Right, After Minimum Quarterly Distributions, Percent														48.00%
AIM Midstream Holdings [Member]
Subsidiary, Sale of Stock [Line Items]
Partners' Capital Account, Percentage																		5.00%
High Point [Member]
Subsidiary, Sale of Stock [Line Items]
Partners' Capital Account, Percentage																		95.00%
Series A-2 [Member]
Subsidiary, Sale of Stock [Line Items]
Issuance of Series A Units												$ 45,000,000
Investment Options, Exercise Price | $ / shares												$ 17.50
Series A
Subsidiary, Sale of Stock [Line Items]
Fair value input, option value | $ / unit								0.07					9.68
Discount rate							18.00%
Distribution growth rate												1.00%
Distribution made to member or limited partner, distributions paid, conversion price per unit | $ / shares							$ 17.50
Partners' Capital Account, Distribution Per Unit of Limited Partner Interest | $ / shares								$ 0.50				$ 0.50
Series B
Subsidiary, Sale of Stock [Line Items]
Issuance of Series A Units													$ 30,000,000
Issuance of Preferred Units [Member] | Series A-2 [Member] | Magnolia Infrastructure Partners, LLC [Member]
Subsidiary, Sale of Stock [Line Items]
Partners' Capital Account, Units, Sold in Private Placement | shares												2,571,430
Issuance of Preferred Units [Member] | Series A | High Point [Member]
Subsidiary, Sale of Stock [Line Items]
Contributed capital							$ 5,142,857				$ 5,142,857
Transaction expenses											2,500,000
Partnership Interest [Member]
Subsidiary, Sale of Stock [Line Items]
Other Ownership Interests, Units Outstanding | shares																					4,526,066
Partnership Interest [Member] | High Point [Member] | AIM Midstream Holdings [Member]
Subsidiary, Sale of Stock [Line Items]
Partnership cancellation of subordinated units (percent)							90.00%
High Point [Member]
Subsidiary, Sale of Stock [Line Items]
Incentive Distribution Right Allocation													85.02%
Costar Midstream, L.L.C. [Member]
Subsidiary, Sale of Stock [Line Items]
Limited partner common units					$ 147,296,000							$ 0	$ 147,296,000
High Point [Member]
Subsidiary, Sale of Stock [Line Items]
Total Consideration for Issuance of Preferred Units							$ 15,000,000				$ 15,000,000
Fourth Amendment [Member] | Revolving Credit Facility [Member] | Series A
Subsidiary, Sale of Stock [Line Items]
Payments on long-term debt							$ (12,500,000)
Series A
Subsidiary, Sale of Stock [Line Items]
Accrued and paid-in-kind unitholder distribution for Series A Units												16,978,000	13,154,000
Series B
Subsidiary, Sale of Stock [Line Items]
Issuance of Series A Units												0	30,000,000	$ 0
Limited partners, units issued | shares																			1,168,225
Series B | Series B
Subsidiary, Sale of Stock [Line Items]
Fair value, paid in kind distributions												$ 1,400,000	$ 2,200,000
Dividend Paid [Member] | Series A
Subsidiary, Sale of Stock [Line Items]
Limited partners, units issued | shares								893,830	466,638			893,830	466,638	135,705
Dividend Paid [Member] | Series B
Subsidiary, Sale of Stock [Line Items]
Limited partners, units issued | shares								94,923	86,461			94,923	86,461
Limited Partner [Member] | Costar Midstream, L.L.C. [Member]
Subsidiary, Sale of Stock [Line Items]
Limited partner common units					$ 6,900,000
Subsequent Event [Member]
Subsidiary, Sale of Stock [Line Items]
Distribution Made to Limited Partner, Distributions Declared, Per Unit, Annualized Basis | $ / shares	$ 1.89
Distribution declared per common unit (a) | $ / shares	$ 0.4725
Interest Rate Swap [Member] | Subsequent Event [Member]
Subsidiary, Sale of Stock [Line Items]
EscrowedUnitsReturnedtoPartnership | shares															1,034,483

Partners' Capital Cash Distribu

Partners' Capital Cash Distributions (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Class of Stock [Line Items]
Distributions	$ 53,386	$ 28,009	$ 16,120
Preferred Partner [Member] | Series A
Class of Stock [Line Items]
Distributions	0	2,658	2,375
Limited Partner [Member]
Class of Stock [Line Items]
Distributions	46,597	22,656	8,207
Limited Party, Subordinated [Member]
Class of Stock [Line Items]
Distributions	0	0	5,073
General Partner [Member]
Class of Stock [Line Items]
Distributions	1,187	333	284
General Partner, Incentive Distribution Rights [Member]
Class of Stock [Line Items]
Distributions	$ 5,602	$ 2,362	$ 181

Earnings per Unit (Details)

Earnings per Unit (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Net income (loss) from continuing operations	$ (121,634)	$ (4,574)	$ (2,002)	$ 835	$ (94,261)	$ (2,397)	$ (1,095)	$ 558	$ (127,375)	$ (97,195)	$ (30,993)
Net income (loss) attributable to noncontrolling interests	(55)	$ 34	$ 32	$ 14	$ 7	$ 33	$ 66	$ 108	25	214	633
Net income (loss) from continuing operations attributable to the Partnership									(127,400)	(97,409)	(31,626)
Distributions on Series A preferred units	$ 4,400								16,978	14,492	24,117
Distributions									53,386	28,009	16,120
General partner's share in undistributed loss									(2,569)	(1,820)	(1,708)
Net income (loss) from continuing operations available to limited Partners									(149,972)	(114,995)	(53,783)
Net income (loss) from discontinued operations available to Limited Partners									(80)	(603)	(2,051)
Net income (loss) available to Limited Partners									$ (150,052)	$ (115,598)	$ (55,834)
Weighted average number of units used in computation of Limited Partners' net income (loss) per unit (basic and diluted)									24,983	13,472	7,525
Limited Partners' net income (loss) from continuing operations per unit (basic and diluted)	$ (4.16)	$ (0.48)	$ (0.35)	$ (0.19)	$ (4.98)	$ (0.58)	$ (0.55)	$ (0.31)	$ (6)	$ (8.54)	$ (7.15)
Limited Partners' net income (loss) from discontinued operations per unit (basic and diluted)	0	0	0	0	0	0	(0.04)	(0.01)	0	(0.04)	(0.27)
Limited partners’ net income (loss) per unit (basic and diluted)	$ (4.16)	$ (0.48)	$ (0.35)	$ (0.19)	$ (4.98)	$ (0.58)	$ (0.59)	$ (0.32)	$ (6)	$ (8.58)	$ (7.42)
Series B
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Distributions									$ 1,373	$ 2,220	$ 0
Blackwater [Member]
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Net income (loss) from continuing operations									0	0	(716)
General Partner [Member]
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Distributions									7,023	2,913	623
General Partner [Member] | Dividend Declared [Member]
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Distributions									$ 6,790	$ 2,694	$ 464

Long-Term Incentive Plan (Unit-

Long-Term Incentive Plan (Unit-based Awards) (Details) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Allocated Share-based Compensation Expense		$ 3,774	$ 1,536	$ 2,094
Weighted average volatility		47.00%
Expected dividend yield		26.30%
Weighted average expected term (in years)		3 years 6 months
Weighted average risk-free rate		1.30%
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Outstanding [Roll Forward]
Outstanding at beginning of period		201,132
Granted		546,329
Forfeited		(31,298)
Vested		(146,404)
Outstanding at end of period	569,759	569,759	201,132
Outstanding at beginning of period		$ 19.85
Granted		12.25
Forfeited		15.62
Vested		18.47
Outstanding at end of period	$ 13.15	$ 13.15	$ 19.85
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding
Outstanding at beginning of period		0
Granted	200,000	200,000
Forfeited		0
Vested		$ 0
Outstanding at end of period	200,000	200,000	0
Outstanding at beginning of period		$ 0
Granted	$ 7.50	7.50
Forfeited		0
Vested		0
Outstanding at end of period	$ 7.50	$ 7.50	$ 0
Performance Shares [Member]
Allocated Share-based Compensation Expense		$ 500

Long Term Incentive Plan (Textu

Long Term Incentive Plan (Textual) (Details) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Feb. 11, 2016	Nov. 30, 2015	Jul. 11, 2012
Subsequent Event [Line Items]
Employee Service Share-based Compensation, Nonvested Awards, Compensation Not yet Recognized, Stock Options	$ 100	$ 100
Equity compensation expense		$ 3,774	$ 1,536	$ 2,094
Long-term incentive plan, increase in available awards							871,750
Long term incentive plan available for future grant	15,484	15,484	688,976	855,089
Grants issued under long term incentive plan	25.00%	25.00%
Total fair value of vested units		$ 2,600	$ 1,400	$ 2,200
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized	$ 5,900	$ 5,900	$ 3,100	$ 900
Weighted average period cost recognized		2 years 9 months
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Aggregate Intrinsic Value, Nonvested						$ 2,000
Granted	200,000	200,000
Granted	$ 7.50	$ 7.50
Subsequent Event [Member]
Subsequent Event [Line Items]
Long-term incentive plan, increase in available awards					6,000,000
Performance Shares [Member]
Subsequent Event [Line Items]
Equity compensation expense		$ 500
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized	$ 1,500	$ 1,500

Post-Employment Benefits (Detai

Post-Employment Benefits (Details Textual) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Benefit Obligation	$ 0.6	$ 0.7
Defined Benefit Plan, Fair Value of Plan Assets	1.8	$ 1.7
Defined Benefit Plan, Net Periodic Benefit Cost	(0.1)
2,016	$ 0.1

Income Tax (Details)

Income Tax (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Operating Loss Carryforwards [Line Items]
Income (Loss) from Continuing Operations before Income Taxes, Extraordinary Items, Noncontrolling Interest	$ (126,241)	$ (96,638)	$ (31,488)
Effective income tax rate, continuing operations	34.00%	34.00%	34.00%
Operating Loss Carryforwards	$ 19,300
Net operating loss carryforwards	7,570	$ 4,173
Other	493	213
Total deferred tax assets	8,063	4,386
Property, plant and equipment	13,889	9,112
Intangible assets	0	387
Total deferred tax liabilities	13,889	9,499
Income Tax Reconciliation, Income Tax Expense (Benefit), at Federal Statutory Income Tax Rate	42,922	32,857	$ 10,706
Partnership loss not subject to income tax	(43,812)	(33,216)	(10,296)
Income not subject to corporate-level tax	0	0	222
State and local tax (benefit) expense	(103)	(159)	71
Other	(141)	(39)	(208)
Income tax (expense) benefit	(1,134)	(557)	495
Deferred Tax Liabilities, Net	(5,826)	(5,113)
Current income tax benefit (expense)	0	(10)	0
Deferred income tax benefit (expense)	$ (1,134)	$ (547)	$ 495
Effective income tax rate	0.90%	0.60%	1.60%

Commitments and Contingencies81

Commitments and Contingencies (Contractual Obligations) (Details) $ in Thousands	Dec. 31, 2015USD ($)
Future Non Cancelable Commitment [Line Items]
2,016	$ 10,543
2,017	2,286
2,018	1,173
2,019	1,345
2,020	1,006
Thereafter	30,086
Total	46,439
Operating leases and service contract [Member]
Future Non Cancelable Commitment [Line Items]
2,016	3,721
2,017	2,286
2,018	1,173
2,019	1,345
2,020	1,006
Thereafter	1,537
Total	11,068
ARO [Member]
Future Non Cancelable Commitment [Line Items]
2,016	6,822
2,017	0
2,018	0
2,019	0
2,020	0
Thereafter	28,549
Total	$ 35,371

Commitments and Contingencies82

Commitments and Contingencies (Details Textual) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Feb. 05, 2014
Loss Contingencies [Line Items]
Incentive Distribution Right Allocation		100.00%
Class of Warrant or Right, Number of Securities Called by Warrants or Rights				300,000
Class of Warrant or Right, Exercise Price of Warrants or Rights				$ 0.01
Operating leases	$ 12	$ 5.8	$ 1.1
High Point [Member]
Loss Contingencies [Line Items]
Partners' Capital Account, Percentage				95.00%
AIM Midstream Holdings [Member]
Loss Contingencies [Line Items]
Partners' Capital Account, Percentage				5.00%
High Point [Member]
Loss Contingencies [Line Items]
Incentive Distribution Right Allocation		85.02%

Related- Party Transactions (De

Related- Party Transactions (Details Textual) - USD ($)	Jan. 31, 2014	Dec. 17, 2013	Apr. 15, 2013	Mar. 31, 2014	Apr. 15, 2013	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Oct. 08, 2015	Sep. 15, 2015	Sep. 10, 2015	Aug. 20, 2014	Jan. 29, 2014	Dec. 11, 2013
Related Party Transactions (Textual) [Abstract]
Cost of business development activities						$ (1,500,000)	$ (900,000)
Proceeds from Sale of Other Assets, Investing Activities						3,900,000
Related Party Transaction, Purchases from Related Party						300,000
Management Fees Revenue						1,400,000	900,000
Related Party Transaction, Due from (to) Related Party						3,800,000	800,000
Issuance of Series A Units						44,768,000	0	$ 14,393,000
Payments on long-term debt						(189,150,000)	(250,870,000)	(131,571,000)
Distributions						$ 53,386,000	$ 28,009,000	$ 16,120,000
Limited partners, units issued						30,427,000	22,670,000	7,414,000	151,937	7,500,000	7,500,000	4,622,352	3,400,000	2,568,712
American Midstream, LLC [Member]
Related Party Transactions (Textual) [Abstract]
Administrative and operational service expenses						$ 28,700,000	$ 22,600,000	$ 14,200,000
Cost of business development activities						(100,000)	(100,000)	(800,000)
Related Party Transaction, Due from (to) Related Party							700,000
High Point [Member]
Related Party Transactions (Textual) [Abstract]
Total Consideration for Issuance of Preferred Units			$ 15,000,000		$ 15,000,000
Total identifiable net assets			61,900,000		61,900,000
High Point [Member] | Issuance of Preferred Units [Member] | Series A
Related Party Transactions (Textual) [Abstract]
Contributed capital			5,142,857		5,142,857
Transaction expenses					2,500,000
Revolving Credit Facility [Member] | Fourth Amendment [Member] | Series A
Related Party Transactions (Textual) [Abstract]
Payments on long-term debt			(12,500,000)
Blackwater [Member]
Related Party Transactions (Textual) [Abstract]
Total identifiable net assets			$ 22,700,000		$ 22,700,000
Purchase price of business		$ 63,900,000
Distributions				$ 27,700,000				27,650,000
Units issued in business acquisition		125,500
Limited Partner [Member]
Related Party Transactions (Textual) [Abstract]
Distributions						64,714,000	39,150,000	21,628,000
Issuance of Series B Units						0
Limited Partner [Member] | Blackwater [Member]
Related Party Transactions (Textual) [Abstract]
General Partner Noncash Distributions		$ 3,100,000						(3,052,000)
Series B
Related Party Transactions (Textual) [Abstract]
Issuance of Series A Units						0	30,000,000	0
Distributions						1,373,000	2,220,000	$ 0
Limited partners, units issued	1,168,225
Series B | Series B
Related Party Transactions (Textual) [Abstract]
Issuance of Series B Units	$ 30,000,000					$ 1,373,000	$ 32,220,000

Reporting Segments (Details)

Reporting Segments (Details) - USD ($)	3 Months Ended									12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Jun. 30, 2013	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Segment information
Revenue										$ 235,034,000	$ 307,309,000	$ 294,051,000
Gain (loss) on commodity derivatives, net										1,324,000	1,091,000	28,000
Total revenue	$ 48,599,000	$ 55,641,000	$ 67,509,000	$ 64,609,000	$ 80,177,000	$ 70,305,000	$ 77,680,000	$ 80,238,000		236,358,000	308,400,000	294,079,000
Purchases of natural gas, NGLs and condensate										105,883,000	197,952,000	215,053,000
Direct operating expenses										(59,549,000)	(45,702,000)	(32,236,000)
Selling, general and administrative expenses										(27,232,000)	(23,103,000)	(19,079,000)
Equity compensation expense										(3,774,000)	(1,536,000)	(2,094,000)
Depreciation, amortization and accretion expense											28,832,000	29,999,000
Depreciation, amortization and accretion expense										(38,014,000)	(28,832,000)	(30,002,000)
Total operating expenses										234,452,000	297,125,000	298,464,000
Gross Profit	28,067,000	29,134,000	32,304,000	33,776,000	36,227,000	21,332,000	22,167,000	23,081,000		123,281,000	102,807,000	74,821,000
Gain (loss) on sale of assets, net										(3,011,000)	(122,000)	0
Other income (expense)										0	(670,000)	0
Loss on impairment of property, plant and equipment					(99,900,000)				$ (15,200,000)	0	(99,892,000)	(18,155,000)
Goodwill, Impairment Loss										(118,592,000)	0	0
Gain (loss) on involuntary conversion of property, plant and equipment										0	0	343,000
Interest expense										14,745,000	7,577,000	9,291,000
Earnings in unconsolidated affiliates										8,201,000	348,000	0
Income tax (expense) benefit										1,134,000	557,000	(495,000)
Net income (loss)										(127,455,000)	(97,806,000)	(33,406,000)
Net income (loss) attributable to noncontrolling interests	55,000	(34,000)	(32,000)	(14,000)	(7,000)	(33,000)	(66,000)	(108,000)		(25,000)	(214,000)	(633,000)
Income (loss) from discontinued operations, net of tax	(1,000)	(53,000)	(31,000)	5,000	(29,000)	(26,000)	(506,000)	(50,000)		(80,000)	(611,000)	(2,413,000)
Net income (loss) attributable to the Partnership	$ (121,580,000)	$ (4,661,000)	$ (2,065,000)	$ 826,000	$ (94,297,000)	$ (2,456,000)	$ (1,667,000)	$ 400,000		(127,480,000)	(98,020,000)	(34,039,000)
Gathering And Processing [Member]
Segment information
Revenue										173,597,000	203,616,000	205,179,000
Gain (loss) on commodity derivatives, net										1,324,000	1,091,000	28,000
Total revenue										174,921,000	204,707,000	205,207,000
Purchases of natural gas, NGLs and condensate										97,580,000	152,690,000	168,574,000
Direct operating expenses										(39,189,000)	(23,783,000)	(14,574,000)
Gross Profit										76,865,000	50,817,000	36,985,000
Transmission [Member]
Segment information
Revenue										43,682,000	88,189,000	79,041,000
Gain (loss) on commodity derivatives, net										0	0	0
Total revenue										43,682,000	88,189,000	79,041,000
Purchases of natural gas, NGLs and condensate										8,303,000	45,262,000	46,479,000
Direct operating expenses										(13,720,000)	(15,577,000)	(13,259,000)
Gross Profit										35,301,000	42,828,000	32,408,000
Terminals [Member]
Segment information
Revenue										17,755,000	15,504,000	9,831,000
Gain (loss) on commodity derivatives, net										0	0	0
Total revenue										17,755,000	15,504,000	9,831,000
Purchases of natural gas, NGLs and condensate										0	0	0
Direct operating expenses										(6,640,000)	(6,342,000)	(4,403,000)
Gross Profit										11,115,000	9,162,000	5,428,000
Commodity Contract [Member]
Segment information
Gain (loss) on commodity derivatives, net										457,000	(733,000)	200,000
Gain (Loss) on Derivative Instruments [Member] | Commodity Contract [Member]
Segment information
Gain (loss) on commodity derivatives, net										$ 1,610,000	$ 735,000	$ 1,069,000

Reporting Segments Reporting Se

Reporting Segments Reporting Segment (Revenue Earned from Customers that Exceed 10%) (Details)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Segment Reporting Information [Line Items]
Entity-wide revenue by major customer, percentage	100.00%	100.00%	100.00%
Customer A [Member]
Segment Reporting Information [Line Items]
Entity-wide revenue by major customer, percentage	10.00%	22.00%	28.00%
Customer B [Member]
Segment Reporting Information [Line Items]
Entity-wide revenue by major customer, percentage	0.00%	0.00%	13.00%
Customer C [Member]
Segment Reporting Information [Line Items]
Entity-wide revenue by major customer, percentage	0.00%	12.00%	12.00%
Customer D [Member]
Segment Reporting Information [Line Items]
Entity-wide revenue by major customer, percentage	0.00%	10.00%	10.00%
Customer Other [Member]
Segment Reporting Information [Line Items]
Entity-wide revenue by major customer, percentage	90.00%	56.00%	37.00%
Customer Concentration Risk [Member] | Revenue [Member] | Gathering And Processing [Member]
Segment Reporting Information [Line Items]
Entity-wide revenue by major customer, percentage	100.00%	100.00%	100.00%
Customer Concentration Risk [Member] | Revenue [Member] | Transmission [Member]
Segment Reporting Information [Line Items]
Entity-wide revenue by major customer, percentage	100.00%	100.00%	100.00%
Customer Concentration Risk [Member] | Revenue [Member] | Terminals [Member]
Segment Reporting Information [Line Items]
Entity-wide revenue by major customer, percentage	100.00%	100.00%	100.00%
Customer Concentration Risk [Member] | Revenue [Member] | Customer A [Member] | Gathering And Processing [Member]
Segment Reporting Information [Line Items]
Entity-wide revenue by major customer, percentage	12.00%	33.00%	43.00%
Customer Concentration Risk [Member] | Revenue [Member] | Customer B [Member] | Gathering And Processing [Member]
Segment Reporting Information [Line Items]
Entity-wide revenue by major customer, percentage	0.00%	12.00%	19.00%
Customer Concentration Risk [Member] | Revenue [Member] | Customer B [Member] | Terminals [Member]
Segment Reporting Information [Line Items]
Entity-wide revenue by major customer, percentage	13.00%	20.00%	17.00%
Customer Concentration Risk [Member] | Revenue [Member] | Customer J [Member] | Gathering And Processing [Member]
Segment Reporting Information [Line Items]
Entity-wide revenue by major customer, percentage	12.00%	0.00%	0.00%
Customer Concentration Risk [Member] | Revenue [Member] | Customer C [Member] | Transmission [Member]
Segment Reporting Information [Line Items]
Entity-wide revenue by major customer, percentage	0.00%	43.00%	39.00%
Customer Concentration Risk [Member] | Revenue [Member] | Customer D [Member] | Transmission [Member]
Segment Reporting Information [Line Items]
Entity-wide revenue by major customer, percentage	16.00%	16.00%	16.00%
Customer Concentration Risk [Member] | Revenue [Member] | Customer K [Member] | Transmission [Member]
Segment Reporting Information [Line Items]
Entity-wide revenue by major customer, percentage	19.00%	0.00%	0.00%
Customer Concentration Risk [Member] | Revenue [Member] | Customer H [Member] | Terminals [Member]
Segment Reporting Information [Line Items]
Entity-wide revenue by major customer, percentage	0.00%	11.00%	13.00%
Customer Concentration Risk [Member] | Revenue [Member] | Customer I [Member] | Terminals [Member]
Segment Reporting Information [Line Items]
Entity-wide revenue by major customer, percentage	13.00%	0.00%	0.00%
Customer Concentration Risk [Member] | Revenue [Member] | Customer F [Member] | Terminals [Member]
Segment Reporting Information [Line Items]
Entity-wide revenue by major customer, percentage	13.00%	19.00%	20.00%
Customer Concentration Risk [Member] | Revenue [Member] | Customer G [Member] | Terminals [Member]
Segment Reporting Information [Line Items]
Entity-wide revenue by major customer, percentage	21.00%	15.00%	16.00%
Customer Concentration Risk [Member] | Revenue [Member] | Customer Other [Member] | Gathering And Processing [Member]
Segment Reporting Information [Line Items]
Entity-wide revenue by major customer, percentage	76.00%	55.00%	38.00%
Customer Concentration Risk [Member] | Revenue [Member] | Customer Other [Member] | Transmission [Member]
Segment Reporting Information [Line Items]
Entity-wide revenue by major customer, percentage	65.00%	41.00%	45.00%
Customer Concentration Risk [Member] | Revenue [Member] | Customer Other [Member] | Terminals [Member]
Segment Reporting Information [Line Items]
Entity-wide revenue by major customer, percentage	40.00%	35.00%	34.00%

Reporting Segments Assets (Deta

Reporting Segments Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Segment Reporting Information [Line Items]
Total assets	$ 891,296	$ 913,558
Gathering And Processing [Member]
Segment Reporting Information [Line Items]
Total assets	572,824	686,395
Transmission [Member]
Segment Reporting Information [Line Items]
Total assets	133,870	132,767
Terminals [Member]
Segment Reporting Information [Line Items]
Total assets	84,449	68,094
Other Segments [Member]
Segment Reporting Information [Line Items]
Total assets	$ 100,153	$ 26,302

Quarterly Financial Data (Detai

Quarterly Financial Data (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended									12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Jun. 30, 2013	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Quarterly Financial Information Disclosure [Abstract]
Loss on impairment of goodwill										$ 118,592	$ 0	$ 0
Total revenue	$ 48,599	$ 55,641	$ 67,509	$ 64,609	$ 80,177	$ 70,305	$ 77,680	$ 80,238		236,358	308,400	294,079
Gross Profit	28,067	29,134	32,304	33,776	36,227	21,332	22,167	23,081		123,281	102,807	74,821
Operating income (loss)	(123,475)	(1,523)	1,867	3,434	(91,633)	(290)	734	2,450		(119,697)	(88,739)	(22,197)
Net income (loss) from continuing operations	(121,634)	(4,574)	(2,002)	835	(94,261)	(2,397)	(1,095)	558		(127,375)	(97,195)	(30,993)
Income (loss) from discontinued operations, net of tax	(1)	(53)	(31)	5	(29)	(26)	(506)	(50)		(80)	(611)	(2,413)
Net income (loss) attributable to noncontrolling interests	55	(34)	(32)	(14)	(7)	(33)	(66)	(108)		(25)	(214)	(633)
Net income (loss) attributable to the Partnership	(121,580)	(4,661)	(2,065)	826	(94,297)	(2,456)	(1,667)	400		$ (127,480)	$ (98,020)	$ (34,039)
General Partner's Interest in net income (loss)	(1,570)	(60)	(25)	10	(1,232)	(32)	(22)	7
Limited Partners' Interest in net income (loss)	$ (120,010)	$ (4,601)	$ (2,040)	$ 816	$ (93,065)	$ (2,424)	$ (1,645)	$ 393
Income (Loss) from Continuing Operations, Per Outstanding Limited Partnership Unit, Basic	$ (4.16)	$ (0.48)	$ (0.35)	$ (0.19)	$ (4.98)	$ (0.58)	$ (0.55)	$ (0.31)		$ (6)	$ (8.54)	$ (7.15)
Limited Partners' net income (loss) from discontinued operations per unit (basic and diluted)	0	0	0	0	0	0	(0.04)	(0.01)		0	(0.04)	(0.27)
Limited partners’ net income (loss) per unit (basic and diluted)	$ (4.16)	$ (0.48)	$ (0.35)	$ (0.19)	$ (4.98)	$ (0.58)	$ (0.59)	$ (0.32)		$ (6)	$ (8.58)	$ (7.42)
Loss on impairment of property, plant and equipment					$ 99,900				$ 15,200	$ 0	$ 99,892	$ 18,155