Crestwood Midstream Partners 10-Q 8 Nov 13 2013 Q3 Quarterly report Financial data

Document_And_Entity_Informatio

Document And Entity Information	9 Months Ended
	Sep. 30, 2013	Oct. 03, 2013
Document And Entity Information [Abstract]	'	'
Document Type	'10-Q	'
Amendment Flag	'false	'
Document Period End Date	30-Sep-13	'
Document Fiscal Period Focus	'Q3	'
Document Fiscal Year Focus	'2013	'
Entity Registrant Name	'Crestwood Midstream Partners LP	'
Entity Central Index Key	'0001389030	'
Current Fiscal Year End Date	'--12-31	'
Entity Filer Category	'Large Accelerated Filer	'
Entity Common Stock, Shares Outstanding	'	53,765,220	[1]
[1]	On October 7, 2013, Crestwood Midstream Partners LP merged with and into Inergy Midstream, L.P.

Consolidated_Statements_Of_Inc

Consolidated Statements Of Income (USD $)	3 Months Ended			9 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012		Sep. 30, 2013	Sep. 30, 2012
Operating revenues	'	'		'	'
Gathering revenues	$25,188	$21,715	[1]	$73,287	$51,313	[1]
Gathering revenues - related party	18,726	21,658	[1]	57,699	67,120	[1]
Processing revenues	3,548	2,271	[1]	11,522	4,665	[1]
Processing revenues - related party	5,421	6,298	[1]	16,618	19,619	[1]
Compression revenues	4,075	'		11,874	'
Product sales	14,180	11,071	[1]	43,653	29,258	[1]
Total operating revenues	71,138	63,013	[1]	214,653	171,975	[1]
Operating expenses	'	'		'	'
Product purchases	5,295	10,341	[1]	18,197	26,755	[1]
Product purchases - related party	7,556	'		22,191	'
Operations and maintenance	14,895	10,942	[1]	40,503	30,053	[1]
General and administrative	10,367	6,570	[1]	28,536	21,965	[1]
Depreciation, amortization and accretion	14,557	11,568	[1]	49,618	35,909	[1]
Total operating expenses	52,670	39,421	[1]	159,045	114,682	[1]
Goodwill impairment	-4,053	'		-4,053	'
Gain on sale of asset	4,392	'		4,392	'
Operating income	18,807	23,592	[1]	55,947	57,293	[1]
Loss from unconsolidated affiliate	-447	'		-447	'
Interest and debt expense	-11,625	-8,905	[1]	-34,260	-25,425	[1]
Income before income taxes	6,735	14,687	[1]	21,240	31,868	[1]
Income tax expense	347	306	[1]	1,024	884	[1]
Net income	6,388	14,381	[1]	20,216	30,984	[1]
Net income attributable to noncontrolling interest	1,923	'		1,923	'
Net income attributable to Crestwood Midstream Partners LP	4,465	14,381	[1]	18,293	30,984	[1]
General partner's interest in net income attributable to Crestwood Midstream Partners LP	81	7,516	[1]	10,474	15,038	[1]
Limited partners' interest in net income attributable to Crestwood Midstream Partners LP	$4,384	$6,865	[1]	$7,819	$15,946	[1]
Net income attributable to Crestwood Midstream Partners LP per limited partner unit:	'	'		'	'
Basic and Diluted	$0.07	$0.15	[1]	$0.13	$0.36	[1]
[1]	Financial information has been revised to include the results of Crestwood Marcellus Midstream LLC as discussed in Note 2.

Consolidated_Balance_Sheets

Consolidated Balance Sheets (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Current assets	'	'
Cash and cash equivalents	$5,668	$111
Accounts receivable	27,666	21,636
Accounts receivable - related party	24,050	23,755
Insurance receivable	3,072	2,920
Prepaid expenses and other	791	1,941
Total current assets	61,247	50,363
Property, plant and equipment, net of accumulated depreciation of $168,497 in 2013 and $130,030 in 2012	1,144,872	939,846
Intangible assets, net of accumulated amortization of $22,448 in 2013 and $12,814 in 2012	428,880	501,380
Goodwill	99,596	95,031
Investment in unconsolidated affiliate	127,651	'
Deferred financing costs, net	20,719	22,528
Other assets	1,018	1,321
Total assets	1,883,983	1,610,469
Current liabilities	'	'
Accrued additions to property, plant and equipment	41,248	9,213
Capital leases	2,945	3,862
Deferred revenue	2,426	2,634
Accounts payable - related party	4,517	3,088
Accounts payable, accrued expenses and other liabilities	41,035	29,717
Total current liabilities	92,171	48,514
Long-term debt	899,386	685,161
Long-term capital leases	1,252	3,161
Asset retirement obligations	14,633	14,024
Commitments and contingent liabilities (Note 9)	'	'
Partners' capital	'	'
General partner (1,112,674 and 979,614 units issued and outstanding at September 30, 2013 and December 31, 2012)	-2,012	257,353
Total Crestwood Midstream Partners LP partners' capital	778,545	859,609
Noncontrolling interests - preferred equity of subsidiary	97,996	'
Total partners' capital	876,541	859,609
Total liabilities and partners' capital	1,883,983	1,610,469
Common [Member]	'	'
Partners' capital	'	'
Limited partners' capital	653,441	442,348
Class C Unitholders [Member]	'	'
Partners' capital	'	'
Limited partners' capital	'	159,908
Class D Unitholder [Member]	'	'
Partners' capital	'	'
Limited partners' capital	$127,116	'

Consolidated_Balance_Sheets_Pa

Consolidated Balance Sheets (Parenthetical) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, except Share data, unless otherwise specified
Property, plant and equipment, accumulated depreciation	$168,497	$130,030
Intangible assets, accumulated amortization	$22,448	$12,814
General partner units issued	1,112,674	979,614
General partner units outstanding	1,112,674	979,614
Common [Member]	'	'
Common units issued	53,765,676	41,164,737
Common units outstanding	53,765,676	41,164,737
Class C Unitholders [Member]	'	'
Common units issued	'	7,165,819
Common units outstanding	'	7,165,819
Class D Unitholder [Member]	'	'
Common units issued	6,483,129	'
Common units outstanding	6,483,129	'

Consolidated_Statements_Of_Cas

Consolidated Statements Of Cash Flows (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012
Cash flows from operating activities	'	'
Net income	$20,216	$30,984	[1]
Adjustments to reconcile net income to net cash provided by operating activities:	'	'
Depreciation, amortization and accretion	49,618	35,909	[1]
Goodwill impairment	4,053	'
Gain on sale of asset	-4,392	'
Equity-based compensation	2,138	1,528	[1]
Loss from unconsolidated affiliate	447	'
Other non-cash income items	3,203	3,743	[1]
Changes in assets and liabilities:	'	'
Accounts receivable	-6,030	-4,985	[1]
Accounts receivable - related party	-295	4,689	[1]
Insurance receivable	-152	'
Prepaid expenses and other assets	1,453	783	[1]
Accounts payable - related party	1,429	-900	[1]
Accounts payable, accrued expenses and other liabilities	9,665	6,117	[1]
Net cash provided by operating activities	81,353	77,868	[1]
Cash flows from investing activities	'	'
Capital expenditures	-164,596	-34,346	[1]
Acquisitions, net of cash acquired	'	-468,987	[1]
Proceeds from sale of asset	11,000	'
Investment in unconsolidated affiliate	-128,098	'
Other	20	'
Net cash used in investing activities	-281,674	-503,333	[1]
Cash flows from financing activities	'	'
Proceeds from credit facilities	483,400	377,700	[1]
Repayments of credit facilities	-269,000	-337,500	[1]
Payments on capital leases	-3,015	-2,155	[1]
Deferred financing costs paid	-85	-6,489	[1]
Proceeds from issuance of common units, net	118,562	217,508	[1]
Proceeds from issuance of preferred equity of subsidiary, net	96,073	'
Contributions from partners	'	249,680	[1]
Distribution to General Partner for additional interest in CMM	-129,000	'
Distributions to partners	-90,357	-73,653	[1]
Taxes paid for equity-based compensation vesting	-700	-406	[1]
Net cash provided by financing activities	205,878	424,685	[1]
Change in cash and cash equivalents	5,557	-780	[1]
Cash and cash equivalents at beginning of period	111	797	[1]
Cash and cash equivalents at end of period	$5,668	$17	[1]
[1]	Financial information has been revised to include the results of Crestwood Marcellus Midstream LLC as discussed in Note 2.

Consolidated_Statements_Of_Cha

Consolidated Statements Of Changes In Partners' Capital (USD $)		Common [Member]	Class C Unitholders [Member]	Class D Unitholder [Member]	General Partner [Member]	Noncontrolling Interest [Member]	Total
In Thousands
Partners' capital at Dec. 31, 2011		$286,945	$157,386	'	$11,292	'	$455,623
Issuance of units, net of offering costs		217,508	'	'	'	'	217,508
Contributions from partners		'	'	'	249,680	'	249,680
Net income		13,532	2,414	'	15,038	'	30,984	[1]
Equity-based compensation		1,528	'	'	'	'	1,528
Taxes paid for equity-based compensation vesting		-406	'	'	'	'	-406
Distributions to partners		-56,730	'	'	-16,923	'	-73,653
Partners' capital at Sep. 30, 2012	[1]	462,377	159,800	'	259,087	'	881,264
Partners' capital at Dec. 31, 2012		442,348	159,908	'	257,353	'	859,609
Issuance of units, net of offering costs		118,562	'	'	'	'	118,562
Issuance of units		'	'	126,286	-126,286	'	'
Issuance of preferred equity of subsidiary		'	'	'	'	96,073	96,073
Conversion of Class C units to common units		159,908	-159,908	'	'	'	'
Net income		6,989	'	830	10,474	1,923	20,216
Equity-based compensation		2,138	'	'	'	'	2,138
Taxes paid for equity-based compensation vesting		-700	'	'	'	'	-700
Distributions to partners		-75,804	'	'	-14,553	'	-90,357
Distribution to General Partner for additional interest in CMM		'	'	'	-129,000	'	-129,000
Partners' capital at Sep. 30, 2013		$653,441	'	$127,116	($2,012)	$97,996	$876,541
[1]	Financial information has been revised to include the results of Crestwood Marcellus Midstream LLC as discussed in Note 2.

Organization_And_Description_O

Organization And Description Of Business	9 Months Ended
	Sep. 30, 2013
Organization And Description Of Business [Abstract]	'
Organization And Description Of Business	'
	1. ORGANIZATION AND DESCRIPTION OF BUSINESS
	Organization
	Prior to the Crestwood Midstream Partners LP (CMLP) merger with Inergy Midstream, L.P. (NRGM) on October 7, 2013 discussed below, CMLP was a publicly traded Delaware limited partnership formed for the purpose of acquiring and operating midstream assets. CMLP's common units were listed on the New York Stock Exchange (NYSE) under the symbol "CMLP." Crestwood Gas Services GP LLC was the CMLP general partner (General Partner) until the effective date of our Merger described below. On June 5, 2013, our General Partner distributed all of its common units and Class D units that it owned in us to Crestwood Holdings Partners LLC and its affiliates (Crestwood Holdings). Prior to June 19, 2013, the General Partner was owned by Crestwood Holdings. On June 19, 2013, Crestwood Holdings acquired the general partner of Inergy, L.P. (NRGY) and contributed its ownership of our General Partner and incentive distribution rights to NRGY in exchange for NRGY common units.
	On October 7, 2013, CMLP completed the merger (the Merger) with a subsidiary of NRGM pursuant to a merger agreement dated as of May 5, 2013. Immediately following the Merger, CMLP merged with and into NRGM, with NRGM continuing as the surviving entity and changing its name to Crestwood Midstream Partners LP (Crestwood Midstream). The common units of the combined partnership are listed on the NYSE under the symbol "CMLP." Under the merger agreement, CMLP unitholders received 1.07 units of NRGM units for each unit of CMLP they owned and as a result, there were no CMLP common or Class D units outstanding immediately following the Merger. Additionally, CMLP unitholders (other than Crestwood Holdings), received a onetime approximately $35 million cash payment at the closing of the Merger, or $1.03 per unit, $25 million of which was paid by NRGM and approximately $10 million of which was paid by Crestwood Holdings. Also in conjunction with the Merger, CMLP was delisted on the NYSE.
	Organizational Structure – Will be updated to reflect Preferred Units in Crestwood Niobrara
	The following chart depicts our ownership structure as of September 30, 2013:
	(1) Concurrent with the October 7, 2013 merger discussed above, NRGY changed its name from Inergy, L.P. to Crestwood Equity Partners LP and changed its NYSE listing symbol from "NRGY" to "CEQP."
	Description of Business
	We are a growth-oriented midstream master limited partnership which owns and operates predominately fee-based gathering, processing, treating and compression assets servicing producers in the Marcellus Shale in northern West Virginia, the Barnett Shale in north Texas, the Fayetteville Shale in northwestern Arkansas, the Granite Wash in the Texas Panhandle, the Avalon Shale/Bone Spring in southeastern New Mexico and the Haynesville/Bossier Shale in western Louisiana.

Basis_Of_Presentation_And_Summ

Basis Of Presentation And Summary Of Significant Accounting Policies	9 Months Ended
	Sep. 30, 2013
Basis Of Presentation And Summary Of Significant Accounting Policies [Abstract]	'
Basis Of Presentation And Summary Of Significant Accounting Policies	'
	2. BASIS OF PRESENTATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES
	Basis of Presentation
	We prepared this Quarterly Report on Form 10-Q under the rules and regulations of the SEC and in accordance with accounting principles generally accepted in the United States of America (GAAP) for interim consolidated financial statements. Accordingly, they do not include all of the disclosures required by GAAP.
	On March 26, 2012, Crestwood Holdings contributed approximately $244 million for a 65% membership interest in Crestwood Marcellus Midstream LLC (CMM) and we contributed approximately $131 million for a 35% membership interest in CMM. On January 8, 2013, we acquired Crestwood Holdings' 65% membership interest in CMM and as a result, we now own 100% of CMM and have the ability to control the operating and financial decisions of CMM. We accounted for this transaction as a reorganization of entities under common control and the accounting standards related to such transactions require us to retroactively adjust our historical results. Accordingly, the consolidated balance sheets reflect the historical carrying value of CMM's assets and liabilities. Earnings related to the recast of our historical results due to the acquisition of the 65% membership interest in CMM were allocated to the General Partner. As a result, there was no impact to our 2012 reported basic or diluted earnings per limited partner unit. We funded the purchase price for the 65% membership interest in CMM of approximately $258 million through $129 million of borrowings under our CMLP credit facility, the issuance of 6,190,469 Class D units, representing limited partner interests in us to Crestwood Holdings, and the issuance of 133,060 general partner units to our General Partner. For accounting purposes, because of the consolidation of CMM, we reflected the $129 million cash paid to acquire the 65% interest in CMM and the issuance of Class D units as a reduction of our General Partner's capital.
	You should read this Quarterly Report on Form 10-Q along with our Form 8-K filed with the SEC on May 10, 2013. The financial statements as of September 30, 2013 and for the three and nine months ended September 30, 2013 and 2012 are unaudited. The consolidated balance sheet as of December 31, 2012, was derived from the audited balance sheet filed in our Form 8-K filed with the SEC on May 10, 2013. In management's opinion, all necessary adjustments to fairly present our results of operations, financial position and cash flows for the periods presented have been made and all such adjustments are of a normal and recurring nature. Information for interim periods may not be indicative of our operating results for the entire year. Our disclosures in this Form 10-Q are an update to those provided in our Form 8-K filed with the SEC on May 10, 2013.
	Significant Accounting Policies
	There were no changes in the significant accounting policies described in our 2012 Annual Report on Form 10-K filed with the SEC on February 27, 2013, except as noted below.
	Revenues
	Our revenues are generated from the gathering, compression and processing of natural gas from producers predominately under fee-based contracts. Our gathering revenues relate to contracts pursuant to which we both transport and compress natural gas based on the volumes that flow through our systems and are not directly dependent on commodity prices. Compression revenues relate to contracts under which we solely provide compression services or contracts under which we charge a compression services fee that is separate from other services provided under our contracts. For the three and nine months ended September 30, 2013, our compression revenues were entirely comprised of services provided under contracts obtained in the E. Marcellus Asset Company, LLC (EMAC) acquisition (See Note 3). The majority of our processing revenues are generated from contracts under which we charge a fixed-fee. Under certain of our processing contracts, raw natural gas is gathered, processed and sold at published index prices. Producers are paid based on an agreed percentage of the residue gas and NGLs multiplied by index prices or the actual sale prices.
	Goodwill
	Our goodwill represents consideration paid in excess of the fair value of the identifiable assets acquired in a business combination. We have assigned our goodwill to four of our operating segments (Marcellus, Granite Wash, Fayetteville and Haynesville) which, based on management's judgment, we also consider reporting units for goodwill assessment purposes.
	We evaluate goodwill for impairment, at a minimum, annually on December 31, or whenever events or changes indicate that it is more likely than not that the fair value of a reporting unit could be less than its carrying amount. This evaluation requires us to compare the fair value of each of the three reporting units above to its carrying value (including goodwill). If the fair value exceeds the carry amount, goodwill of the reporting unit is not considered impaired.
	We estimate the fair value of our reporting units based on a number of factors, including the potential value we would receive if we sold the reporting unit, discount rates and projected cash flows. Projected cash flows of the reporting unit are generally based on current and anticipated future market conditions, which require significant judgment to make projections and assumptions about pricing, demand, competition, operating costs, legal and regulatory issues and other factors that may extend many years into the future and are often outside of our control. Due to the imprecise nature of these projections and assumptions, actual results can and often do, differ from our estimates.
	During the three months ended September 30, 2013, we recorded an impairment of goodwill of approximately $4 million on our Haynesville/Bossier Shale system as a result of a decrease in anticipated revenues to be generated from those operations due primarily to our inability to renew and extend a significant revenue contract that expired in mid-2013.
	Investment in Unconsolidated Affiliate
	We apply the equity method of accounting where we can exert significant influence over, but do not control or direct, the policies, decisions or activities of the entity. We use the cost method of accounting where we are unable to exert significant influence over the entity. The Financial Accounting Standards Board's accounting standards related to equity method investments and joint ventures requires entities to periodically review their equity method investments to determine whether current events or circumstances indicate that the carrying value of the equity method investment may be impaired. We evaluate our equity method investment for impairment when there are indicators of impairment. If indicators suggest impairment we will perform an impairment test to assess whether an adjustment is necessary. The impairment test considers whether the fair value of our equity method investment has declined and if any such decline is other than temporary. If a decline in fair value is determined to be other than temporary, the investment's carrying value is written down to fair value.

Acquisitions_And_Divestitures

Acquisitions And Divestitures	9 Months Ended
	Sep. 30, 2013
Acquisitions And Divestitures [Abstract]	'
Acquisitions And Divestitures	'
	3. ACQUISITIONS AND DIVESTITURES
	Acquisitions
	Antero Acquisition
	On February 27, 2012, we announced the execution, through CMM, of an Asset Purchase Agreement related to the acquisition of gathering assets owned by Antero Resources Appalachian Corporation (Antero) in the Marcellus Shale located in Harrison and Doddridge Counties, West Virginia (Antero Acquisition), and, at closing, the planned execution of a 20 year, fixed-fee, Gas Gathering and Compression Agreement (GGA) with Antero. On March 26, 2012, CMM completed the Antero Acquisition for approximately $380 million. The assets acquired by CMM consisted of a 33 mile low pressure gathering system which delivers Antero's Marcellus Shale production to various regional pipeline systems including Columbia, Dominion, Equitrans and MarkWest Energy Partners' Sherwood Gas Processing Plant.
	The GGA with Antero provides for an area of dedication at the time of acquisition of approximately 127,000 gross acres, or 104,000 net acres, largely located in the rich gas corridor of the southwestern core of the Marcellus Shale play. As part of the GGA, Antero committed to deliver minimum annual throughput volumes to us for a seven year period from January 1, 2012 to January 1, 2019, ranging from an average of 300 million cubic feet per day (MMcf/d) in 2012 to an average of 450 MMcf/d in 2018. During the period ended December 31, 2012, Antero delivered less than the minimum annual throughput volumes and at December 31, 2012, we recorded a receivable and deferred revenue of approximately $2.6 million due to Antero's potential ability to recover this amount if Antero's 2013 throughput volumes exceed the minimum annual throughput volumes included in the GGA for 2013.
	The final purchase price allocation is as follows (In thousands):
	Cash	$	381,718
	Total purchase price	$	381,718
	Purchase price allocation:
	Property, plant and equipment	$	90,562
	Intangible assets		291,218
	Total assets	$	381,780
	Asset retirement obligation	$	62
	Total liabilities	$	62
	Total	$	381,718
	Our intangible assets recorded as a result of the Antero Acquisition relate to the GGA with Antero. These intangible assets will be amortized over the life of the contract. For the period from the acquisition date (March 26, 2012) to September 30, 2012, we recorded approximately $15 million of operating revenues and $7 million of operating expenses related to the operations of the assets acquired from Antero.
	Devon Acquisition
	On August 24, 2012, we completed the acquisition of certain gathering and processing assets in the NGL rich gas region of the Barnett Shale (Devon Acquisition) from Devon Energy Corporation (Devon). We paid approximately $88 million for these assets. During the three months ended September 30, 2013, we finalized the purchase price allocation of the assets acquired and liabilities assumed, and as a result, we reduced our depreciation, amortization and accretion expense by approximately $2 million.
	The final purchase price allocation is as follows (In thousands):
	Cash	$	87,943
	Total purchase price	$	87,943
	Purchase price allocation:
	Property, plant and equipment	$	88,626
	Total assets	$	88,626
	Asset retirement obligation	$	483
	Environmental liability		200
	Total liabilities	$	683
	Total	$	87,943
	We believe that it is impracticable to present financial information for the acquired assets prior to the acquisition date due to the lack of availability of historical financial information related to the acquired assets, and because the 20 year fixed-fee gathering, processing and compression agreement with Devon has significantly different terms than the historical intercompany relationships between the acquired assets and Devon.
	EMAC Acquisition
	On December 28, 2012, CMM acquired all of the membership interest of E. Marcellus Asset Company, LLC (EMAC) from Enerven Compression, LLC (Enerven) for approximately $95 million. We financed this acquisition through our CMM credit facility. At the time of acquisition, EMAC's assets consisted of four compression and dehydration stations located on our gathering systems in Harrison County, West Virginia. These assets provide compression and dehydration services to Antero under a compression services agreement through 2018. Antero has the option to renew the agreement for an additional five years upon expiration of the original agreement.
	During the three months ended September 30, 2013, we finalized the purchase price allocation of the assets acquired and liabilities assumed, and as a result, we reduced our depreciation, amortization and accretion expense by approximately $1 million. In addition, we recognized goodwill of approximately $9 million, primarily related to anticipated operating synergies between the assets acquired and our existing assets.
	The final purchase price allocation is as follows (In thousands):
	Cash	$	94,979
	Total purchase price	$	94,979
	Purchase price allocation:
	Property, plant and equipment	$	53,357
	Intangible assets		33,909
	Goodwill		8,618
	Total assets	$	95,884
	Asset retirement obligation	$	755
	Environmental liability		150
	Total liabilities	$	905
	Total	$	94,979
	Our intangible assets recorded as a result of the EMAC acquisition relate to the compression services agreements with Antero. These intangible assets will be amortized over the life of the contract. Pro forma information has not been provided for the acquisition of the EMAC assets as the impact is immaterial to our financial statements.
	Divestitures
	On July 25, 2013, we sold a cryogenic plant and associated equipment for approximately $11 million (net of fees) and recognized a gain of approximately $4 million during the three months ended September 30, 2013.

Earnings_Per_Limited_Partner_U

Earnings Per Limited Partner Unit And Distributions	9 Months Ended
	Sep. 30, 2013
Earnings Per Limited Partner Unit And Distributions [Abstract]	'
Earnings Per Limited Partner Unit And Distributions	'
	4. EARNINGS PER LIMITED PARTNER UNIT AND DISTRIBUTIONS
	Earnings Per Limited Partner Unit. Our net income attributable to CMLP is allocated to the General Partner and the limited partners, in accordance with their respective ownership percentages, after giving effect to incentive distributions paid to the General Partner. To the extent cash distributions exceed net income attributable to CMLP, the excess distributions are allocated proportionately to all participating units outstanding based on their respective ownership percentages. Basic earnings per unit are computed by dividing net income attributable to limited partner unitholders by the weighted-average number of limited partner units outstanding during each period. Diluted earnings per unit are computed using the treasury stock method, which considers the impact to net income attributable to CMLP and limited partner units from the potential issuance of limited partner units.
	The tables below show the (i) allocation of net income attributable to limited partners and the (ii) net income attributable to CMLP per limited partner unit based on the number of basic and diluted limited partner units outstanding for the three and nine months ended September 30, 2013 and 2012.
	Allocation of Net Income Attributable to CMLP to General Partner and Limited Partners
			Three Months Ended						Nine Months Ended
			September 30,						September 30,
			2013			2012			2013			2012
			(In thousands)
	Net income attributable to CMLP	$	4,465		$	14,381		$	18,293		$	30,984
	General Partner's incentive distributions (1)		—			(4,101	)		(10,140	)		(10,636	)
	Net income attributable to CMLP after incentive distributions		4,465			10,280			8,153			20,348
	General Partner's interest in net income attributable to CMLP
	after incentive distributions		(81	)		(3,415	)		(334	)		(4,402	)
	Limited Partners' interest in net income attributable to CMLP
	after distributions	$	4,384		$	6,865		$	7,819		$	15,946
	(1) As a result of the Merger on October 7, 2013 described in Note 1. Organization and Description of Business, there were no distributions to CMLP's unitholders for the three months ended September 30, 2013; therefore, our General Partner did not receive any incentive distributions attributable to that period.
	Earnings Per Limited Partner Unit
	Three Months Ended September 30,
			2013		2012
	Limited partners' interest in net income attributable to CMLP	$	4,384	$	6,865
	Weighted-average limited partner units—basic (1)		60,188		46,564
	Effect of dilutive units		260		203
	Weighted-average limited partner units—diluted (1)		60,448		46,767
	Basic and diluted net income attributable to CMLP per limited
	partner unit	$	0.07	$	0.15
	(1) The three months ended September 30, 2013 includes 6,421,641 Class D units. The three months ended September 30, 2012 includes 6,929,763 Class C units.
	Nine Months Ended September 30,
			2013		2012
	Limited partners' interest in net income attributable to CMLP	$	7,819	$	15,946
	Weighted-average limited partner units—basic (1)		58,339		44,206
	Effect of dilutive units		269		189
	Weighted-average limited partner units—diluted (1)		58,608		44,395
	Basic and diluted net income attributable to CMLP per limited
	partner unit	$	0.13	$	0.36
	(1) The nine months ended September 30, 2013 includes 8,536,178 Class C and Class D units. The nine months ended September 30, 2012 includes 6,795,130 Class C units.
	We exclude potentially dilutive securities from the determination of diluted earnings per unit (as well as their related income statement impacts) when their impact on net income attributable to CMLP per limited partner unit is anti-dilutive. For the three and nine months ended September 30, 2013, we excluded 3,262,275 and 1,099,375 preferred security units issued by our consolidated subsidiary, Crestwood Niobrara LLC (Crestwood Niobrara), from our diluted earnings per unit. There were no units excluded from our diluted earnings per unit as we did not have any anti-dilutive units for the three and nine months ended September 30, 2012. Our potentially dilutive securities for the three and nine months ended September 30, 2013 and 2012 consist of unvested phantom units.
	Distributions. Our Second Amended and Restated Agreement of Limited Partnership, dated February 19, 2008, as amended (Partnership Agreement), requires that, within 45 days after the end of each quarter, we distribute all of our Available Cash (as defined therein) to unitholders of record on the applicable record date, as determined by our General Partner. As a result of the Merger on October 7, 2013 described in Note 1. Organization and Description of Business, there were no distributions to CMLP's unitholders for the three months ended September 30, 2013. Under the merger agreement, CMLP unitholders received 1.07 units of NRGM units for each unit of CMLP they owned and such unitholders will receive a distribution for the three months ended September 30, 2013 as determined by Crestwood Midstream's board of directors.
	The following table presents distributions for 2013 and 2012 (In millions, except per unit data):
					Distributions Paid
					Limited Partner						General Partner
								Paid-In-Kind		Paid-In-Kind		Cash paid		Paid-In-Kind		Paid-In-Kind
								Value to		Value to		to General		Value to		Value to
		Attributable to the Per Unit				Cash paid		Class C		Class D		Partner		Class C		Class D		Total		Total
	Payment Date	Quarter Ended		Distribution		to common(1)		unitholders		unitholder		and IDR		unitholder		unitholder		Cash		Distribution
	2013
	August 9,
	2013	30-Jun-13	$	0.51	$	27.4	$	—	$	3.2	$	5.2	$	—	$	0.5	$	32.6	$	36.3
	May 10,
	2013	31-Mar-13	$	0.51	$	27.4	$	—	$	3.2	$	5.2	$	—	$	0.5	$	32.6	$	36.3
	February 12,
	2013	31-Dec-12	$	0.51	$	21	$	3.7	$	—	$	4.1	$	0.6	$	—	$	25.1	$	29.4
	2012
	November 9,
	2012	30-Sep-12	$	0.51	$	21	$	3.5	$	—	$	4.1	$	0.6	$	—	$	25.1	$	29.2
	August 10,
	2012	30-Jun-12	$	0.5	$	20.6	$	3.4	$	—	$	3.7	$	0.5	$	—	$	24.3	$	28.2
	May 11,
	2012	31-Mar-12	$	0.5	$	18.2	$	3.4	$	—	$	3.3	$	0.5	$	—	$	21.5	$	25.4
	February 10,
	2012	31-Dec-11	$	0.49	$	17.9	$	3.2	$	—	$	2.8	$	0.5	$	—	$	20.7	$	24.4
	(1) Distributions for the quarters ended June 30, 2012 and September 30, 2012 exclude approximately $3 million and $4 million paid by CMM to Crestwood Holdings.
	Our Class D units are substantially similar in all respects to our existing common units, representing limited partner interests, except that we have the option to pay distributions to our Class D unitholders with cash or by issuing additional Paid-In-Kind Class D units, based upon the volume weighted-average price of our common units for the 10 trading days immediately preceding the date the distribution is declared. We issued 151,238 and 141,422 additional Class D units in lieu of paying cash quarterly distributions on our Class D units attributable to the quarters ended March 31, 2013 and June 30, 2013.
	On April 1, 2013, our outstanding Class C units converted to common units on a one-for-one basis. Prior to the conversion of our Class C units to common, we had the option to pay distributions to our Class C unitholders with cash or by issuing additional Paid-In-Kind Class C units, based upon the volume weighted-average price of our common units for the 10 trading days immediately preceding the date the distribution is declared. The unitholders of the converted units received a quarterly cash distribution for the period ended March 31, 2013 although the Class C units were not converted until April 1, 2013. We issued 136,128, 138,731 and 174,230 additional Class C units in lieu of paying cash quarterly distributions on our Class C units attributable to the quarters ended March 31, 2012, June 30, 2012 and September 30, 2012.
On March 22, 2013, we completed a public offering of 4,500,000 common units, representing limited partner interests in us, at a price of $23.90 per common unit ($23.00 per common unit, net of underwriting discounts) providing net proceeds of approximately $103.5 million. We granted the underwriters a 30-day option to purchase up to 675,000 additional common units if the underwriters sold more than 4,500,000 common units in the offering. The underwriters exercised this option on April 5, 2013 providing net proceeds of approximately $15.5 million. The unitholders of these common units received a quarterly distribution for the period ended March 31, 2013.

Investment_In_Unconsolidated_A

Investment In Unconsolidated Affiliate	9 Months Ended
	Sep. 30, 2013
Investment In Unconsolidated Affiliate [Abstract]	'
Investment In Unconsolidated Affiliate	'
	5. INVESTMENT IN UNCONSOLIDATED AFFILIATE
	On July 19, 2013, Crestwood Niobrara acquired RKI Exploration and Production, LLC's (RKI) 50% interest in Jackalope Gas Gathering Services, L.L.C. (Jackalope) for approximately $108 million. RKI is a privately-owned, independent exploration and production company in which an affiliate of our General Partner owns a significant minority ownership interest, and therefore is considered our related party. Access Midstream Partners, L.P. (Access) owns the remaining 50% interest in and operates Jackalope. Crestwood Niobrara manages the commercial operations of the Jackalope system. We account for our investment in Jackalope under the equity method of accounting.
	The Jackalope gathering and processing system is currently comprised of approximately 100 miles of gathering pipelines and 9,400 horsepower of compression equipment located in Converse County, Wyoming. The existing Jackalope assets and planned future development are supported by a 20-year gathering and processing agreement with Chesapeake Energy Corporation and RKI under which Jackalope receives cost-of-service based fees with annual redeterminations. The gathering and processing agreements provide for an area of dedication of approximately 311,000 gross acres located in the core of the Powder River Basin Niobrara Shale. During the three months ended September 30, 2013, Crestwood Niobrara contributed an additional $20 million to Jackalope to fund its construction projects.
	We have reflected the earnings from our investment in Jackalope in our consolidated statements of income, which includes our share of net earnings based on our ownership interest and other adjustments recorded by us as discussed below. During the three and nine months ended September 30, 2013, our share of Jackalope's net earnings was approximately $0.2 million. As of September 30, 2013, our investment balance in Jackalope exceeded our equity in the underlying net assets of Jackalope by approximately $57 million. We amortize and generally assess the recoverability of this amount based on the life of Jackalope's gathering agreement. The amortization is reflected as a reduction of our earnings from unconsolidated affiliate, and during the three and nine months ended September 30, 2013, we recorded amortization expense of approximately $0.6 million.
	In accordance with the Jackalope limited liability company agreement, Jackalope is required to make quarterly distributions of its available cash to its members based on their respective ownership percentage.

Preferred_Equity_Of_Subsidiary

Preferred Equity Of Subsidiary	9 Months Ended
	Sep. 30, 2013
Preferred Equity Of Subsidiary [Abstract]	'
Preferred Equity Of Subsidiary	'
	6. PREFERRED EQUITY OF SUBSIDIARY
	In conjunction with Crestwood Niobrara's acquisition discussed in Note 5. Investment in Unconsolidated Affiliate, Crestwood Niobrara issued a preferred interest of approximately $81 million to a subsidiary of General Electric Capital Corporation and GE Structured Finance, Inc. (collectively, GE EFS). The preferred interest is reflected as noncontrolling interest in our consolidated financial statements. During the three and nine months ended September 30, 2013, we allocated approximately $2 million of net income to the noncontrolling interest, which was based on the overall return attributable to the preferred security.
	Crestwood Niobrara will fund 75% of future capital contributions to Jackalope through additional preferred interest issuances to GE EFS (up to a maximum of an additional $69 million), with the remainder to be funded through our capital contributions to Crestwood Niobrara. During the three and nine months ended September 30, 2013, GE EFS contributed approximately $96 million (which consisted of the initial contribution of $81 million and additional capital contributions of approximately $15 million) to Crestwood Niobrara in exchange for an equivalent number of preferred units. The proceeds from the initial GE EFS contribution were used to purchase the investment in Jackalope and the proceeds from the subsequent contributions were used to fund capital contributions to the Jackalope investment.
	In accordance with the Crestwood Niobrara limited liability company agreement, Crestwood Niobrara has the option to pay distributions to GE EFS with cash or by issuing additional preferred units through the January 2015 distribution. On October 30, 2013, Crestwood Niobrara issued GE EFS approximately 2,161,657 million units in lieu of paying a cash distribution. We serve as the managing member of Crestwood Niobrara and, subject to certain restrictions, we have the ability to redeem GE EFS' preferred security in either cash or CMLP common units of the combined partnership as discussed in Note 1. Organization and Description of Business.

Financial_Instruments

Financial Instruments	9 Months Ended
	Sep. 30, 2013
Financial Instruments [Abstract]	'
Financial Instruments	'
	7. FINANCIAL INSTRUMENTS Fair Values
	We separate the fair values of our financial instruments into three levels (Levels 1, 2 and 3) based on our assessment of the availability of observable market data and the significance of non-observable data used to determine fair value. Our assessment and classification of an instrument within a level can change over time based on the maturity or liquidity of the instrument and would be reflected at the end of the period in which the change occurs. At September 30, 2013 and December 31, 2012, there have been no changes to the inputs and valuation techniques used to measure fair value, the types of instruments, or the levels in which they are classified.
	Cash and Cash Equivalents, Accounts Receivable and Accounts Payable. As of September 30, 2013 and December 31, 2012, the carrying amounts of cash and cash equivalents, accounts receivable and accounts payable represent fair value based on the short-term nature of these instruments.
	Credit Facilities. The fair value of our credit facilities approximates their carrying amounts as of September 30, 2013 and December 31, 2012 due primarily to the variable nature of the interest rate of the instrument, which is considered a Level 2 fair value measurement.
	Senior Notes. We estimated the fair value of our 7.75% Senior Notes due April 2019 (Senior Notes) (representing a Level 2 fair value measurement) primarily based on quoted market prices for the same or similar issuances. The following table reflects the carrying value and fair value of our Senior Notes (In millions):
			30-Sep-13				31-Dec-12
			Carrying		Fair		Carrying		Fair
			Amount		Value		Amount		Value
	Senior Notes	$	351	$	369	$	351	$	365
	Debt
	Our long-term debt consists of the following (In thousands):
			September 30,		December 31,
			2013		2012
	CMM Credit Facility, due March 2017	$	191,900	$	127,000
	CMLP Credit Facility, due November 2017		356,200		206,700
	Senior Notes, due April 2019		350,000		350,000
			898,100		683,700
	Plus: Unamortized premium on Senior Notes		1,286		1,461
	Total long-term debt	$	899,386	$	685,161
	Credit Facilities
	CMM Credit Facility. In conjunction with the Merger discussed in Note 1. Organization and Description of Business, we terminated the CMM credit agreement (CMM Credit Facility). No amounts were outstanding under the CMM Credit Facility following the consummation of the Merger. The CMM credit agreement allowed for revolving loans, letters of credit and swingline loans in an aggregate principal amount of up to $200 million. The CMM Credit Facility was secured by substantially all of CMM's assets.
	Borrowings under the CMM Credit Facility bore interest at the London Interbank Offered Rate (LIBOR) plus an applicable margin or base rate as defined in the CMM Credit Facility. Under the terms of the CMM Credit Facility, the applicable margin under LIBOR was 2.8% and 2.5% at September 30, 2013 and December 31, 2012. The weighted-average interest rate at September 30, 2013 and December 31, 2012 was 3.0% and 2.8%. For the three and nine months ended September 30, 2013, our average outstanding borrowings were approximately $157 million and $126 million. For the three and nine months ended September 30, 2013, our maximum outstanding borrowings were approximately $192 million.
	CMLP Credit Facility. In conjunction with the Merger discussed in Note 1. Organization and Description of Business, we terminated the CMLP amended and restated senior secured credit agreement (CMLP Credit Facility). No amounts were outstanding under the CMLP Credit Facility following the consummation of the Merger. The CMLP Credit Facility allowed for revolving loans, letters of credit and swingline loans in an aggregate amount of up to $550 million. The CMLP Credit Facility was secured by substantially all of CMLP's assets and those of certain of its subsidiaries. As of September 30, 2013, the CMLP Credit Facility was guaranteed by our 100% owned subsidiaries except for Crestwood Niobrara and CMM and its consolidated subsidiaries.
	Borrowings under the CMLP Credit Facility bore interest at LIBOR plus an applicable margin or a base rate as defined in the CMLP Credit Facility. Under the terms of the CMLP Credit Facility, the applicable margin under LIBOR borrowings was 2.8% and 2.5% at September 30, 2013 and December 31, 2012. The weighted-average interest rate as of September 30, 2013 and December 31, 2012 was 3.0% and 2.8%. For the three and nine months ended September 30, 2013, our average outstanding borrowings were $343 million and $330 million. For the three and nine months ended September 30, 2013, our maximum outstanding borrowings were $365 million and $373 million.
	Senior Notes
	In November 2012, we issued $150 million aggregate principal amount of 7.75% Senior Notes in a private placement offering. These notes were issued as additional notes under the indenture dated April 1, 2011 among us, Crestwood Midstream Finance Corporation, the guarantors names therein, and The Bank of New York Mellon Trust Company, N.A., as trustee, pursuant to which we previously issued our $200 million aggregate principal amount of 7.75% Senior Notes in April 2011. In conjunction with the Merger discussed in Note 1. Organization and Description of Business, CMLP entered into a supplemental indenture governing the 7.75% Senior Notes. Pursuant to the supplemental indenture, Crestwood Midstream Partners LP (formerly NRGM) and Crestwood Midstream Finance Corp (formerly NRGM Finance Corp.), which we refer to together as the Successor Issuers, have unconditionally assumed all of the obligations under the 7.75% Senior Notes due April 2019. In addition, certain subsidiaries have entered into financial guarantees pursuant to which they unconditionally guarantee the obligations under the indenture and Senior Notes.

Accounts_Payable_Accrued_Expen

Accounts Payable, Accrued Expenses And Other Liabilities	9 Months Ended
	Sep. 30, 2013
Accounts Payable, Accrued Expenses And Other Liabilities [Abstract]	'
Accounts Payable, Accrued Expenses And Other Liabilities	'
	8. ACCOUNTS PAYABLE, ACCRUED EXPENSES AND OTHER LIABILITIES
	Accounts payable, accrued expenses and other liabilities consist of the following (In thousands):
		September 30,		December 31,
		2013		2012
	Accrued expenses	$	11,305	$	9,608
	Accrued property taxes		5,843		5,638
	Accrued product purchases payable		1,818		2,450
	Tax payable		1,353		2,159
	Interest payable		14,054		7,505
	Accounts payable		6,653		2,278
	Other		9		79
	Total accounts payable, accrued expenses and other liabilities	$	41,035	$	29,717

Commitments_And_Contingent_Lia

Commitments And Contingent Liabilities	9 Months Ended
	Sep. 30, 2013
Commitments And Contingent Liabilities [Abstract]	'
Commitments And Contingent Liabilities	'
	9. COMMITMENTS AND CONTINGENT LIABILITIES
	Legal Proceedings
	Class Action Lawsuits. Five putative class action lawsuits challenging the Merger were filed, four in federal court in the United States District Court for the Southern District of Texas: (i) Abraham Knoll v. Robert G. Phillips, et al. (Case No. 4:13-cv-01528, filed May 23, 2013); (ii) Greg Podell v. Crestwood Midstream Partners, LP, et al. (Case No. 4:13-cv-01599, filed May 30, 2013); (iii) Johnny Cooper v. Crestwood Midstream Partners LP, et al. (Case No. 4:13-cv-01660, filed June 7, 2013), subsequently replaced as named plaintiff in this action by Linda Giaimo; and (iv) Steven Elliot LLC v. Robert G. Phillips, et al. (Case No. 4:13-cv-01763, filed June 17, 2013), and one in the Delaware Court of Chancery; Hawley v. Crestwood Midstream Partners LP, et al. (Case No. 8689-VCL, filed June 27, 2013). All the cases name Crestwood, Crestwood Gas Services GP LLC, Crestwood Holdings LLC, the current and former directors of Crestwood Gas Services GP LLC, Inergy, L.P., Inergy Midstream, L.P., NRGM GP, LLC, and Intrepid Merger Sub, LLC as defendants. All of the suits were brought by a purported holder of common units of Crestwood, both individually and on behalf of a putative class consisting of holders of common units of Crestwood. The lawsuits generally alleged, among other things, that the directors of Crestwood Gas Services GP LLC breached their fiduciary duties to holders of common units of Crestwood by agreeing to a transaction with inadequate consideration and unfair terms and pursuant to an inadequate process. The lawsuits further alleged that Inergy, L.P., Inergy Midstream, L.P., NRGM GP, LLC, and Intrepid Merger Sub, LLC aided and abetted the Crestwood directors in the alleged breach of their fiduciary duties. The lawsuits sought, in general, (i) injunctive relief enjoining the merger, (ii) in the event the merger is consummated, rescission or an award of rescissory damages, (iii) an award of plaintiffs' costs, including reasonable attorneys' and experts' fees, (iv) the accounting by the defendants to plaintiffs for all damages caused by the defendants, and (v) such further equitable relief as the court deems just and proper. The four federal actions also asserted claims of inadequate disclosure under Sections 14(a) and 20(a) of the Securities Exchange Act of 1934, and the Elliot case also named Citigroup Global Markets Inc. as an alleged aider and abettor. The plaintiff in the Hawley action in Delaware filed a motion for expedited proceedings but subsequently withdrew that motion and then filed a stipulation voluntarily dismissing the action without prejudice, which was granted by the Court, such that the Hawley action was dismissed. The plaintiff in the Elliot action filed a motion for expedited discovery, which was denied by the Court. The plaintiffs in the Knoll, Podell, Cooper, and Elliot actions filed an unopposed motion to consolidate these four cases, which the Court granted and captioned the consolidated matters as In re: Crestwood Midstream Partners Unitholder Litigation, Lead Case No. 4:12-cv-01528 (the Consolidated Action). The plaintiffs entered into a Memorandum of Understanding (MOU) on September 24, 2013 to settle the Consolidated Action whereby the defendants denied liability. The settlement contemplated by the MOU is subject to a number of conditions, including notice to the class and final court approval following completion of a settlement hearing. The defendants expect the Court to approve the terms of the MOU by the end of the first quarter of 2014. The anticipated settlement of the MOU will not have a material impact to our consolidated financial statements.
	From time to time, we are party to certain legal or administrative proceedings that arise in the ordinary course and are incidental to our business. There are currently no such pending proceedings to which we are a party that our management believes will have a material adverse effect on our results of operations, cash flows or financial condition. However, future events or circumstances, currently unknown to management, will determine whether the resolution of any litigation or claims will ultimately have a material effect on our results of operations, cash flows or financial condition in any future reporting periods. At September 30, 2013 and December 31, 2012, we had $0.4 million and less than $0.1 million accrued for our legal proceedings.
	Regulatory Compliance
	In the ordinary course of our business, we are subject to various laws and regulations. In the opinion of our management, compliance with current laws and regulations will not have a material effect on our results of operations, cash flows or financial condition.
	Environmental Compliance
	Our operations are subject to stringent and complex laws and regulations pertaining to health, safety, and the environment. We are subject to laws and regulations at the federal, state and local levels that relate to air and water quality, hazardous and solid waste management and disposal and other environmental matters. The cost of planning, designing, constructing and operating our facilities must incorporate compliance with environmental laws and regulations and safety standards. Failure to comply with these laws and regulations may trigger a variety of administrative, civil and potentially criminal enforcement measures. At September 30, 2013 and December 31, 2012, we had accrued approximately $0.3 million and $0.2 million for environmental matters, which are based on our undiscounted estimate of amounts we will spend on environmental compliance and remediation. We estimate that our potential liability for reasonably possible outcomes related to our environmental exposures could range from approximately $0.3 million to $0.5 million.

Income_Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2013
Income Taxes [Abstract]	'
Income Taxes	'
	10. INCOME TAXES
	No provision for federal or state income taxes is included in our results of operations as such income is taxable directly to the partners. Accordingly, each partner is responsible for its share of federal and state income tax. Net earnings for financial statement purposes may differ significantly from taxable income reportable to each partner as a result of differences between the tax basis and financial reporting basis of assets and liabilities.
	We are responsible for our portion of the Texas Margin tax that is included in Crestwood Holdings' consolidated Texas franchise tax return. Our current tax liability will be assessed based on 0.7% of the gross revenue apportioned to Texas. The margin tax qualifies as an income tax under GAAP, which requires us to recognize the impact of this tax on the temporary differences between the financial statement assets and liabilities and their tax basis attributable to such tax. See our Form 8-K filed with the SEC on May 10, 2013 for more information about our income taxes.

Equity_Plan

Equity Plan	9 Months Ended
	Sep. 30, 2013
Equity Plan [Abstract]	'
Equity Plan	'
	11. EQUITY PLAN
	In conjunction with the Merger discussed in Note 1. Business and Description of Business, we terminated our Fourth Amended and Restated 2007 Equity Plan (2007 Equity Plan). All of our unvested phantom and restricted units became vested upon consummation of the Merger and all unamortized compensation expense related to those units was recognized on that date. The following table summarizes information regarding phantom and restricted unit activity during the nine months ended September 30, 2013:
		Payable In Cash				Payable In Units
					Weighted-				Weighted-
					Average Grant				Average Grant
					Date Fair				Date Fair
		Units			Value	Units			Value
	Unvested—January 1, 2013	8,312		$	26.45	221,992		$	28.35
	Vested—phantom units	(3,013	)	$	27.22	(71,006	)	$	28.7
	Vested—restricted units	—			—	(11,349	)	$	26.4
	Granted—phantom units	—			—	161,807		$	24.33
	Granted—restricted units	—			—	27,900		$	24.86
	Canceled—phantom units	(354	)	$	25.81	(7,114	)	$	27.96
	Unvested—September 30, 2013	4,945		$	26.02	322,230		$	26.01
	As of September 30, 2013 and December 31, 2012, we had total unamortized compensation expense of approximately $4 million and $3 million related to phantom and restricted units. As discussed above, the vesting period of our phantom and restricted units were accelerated upon consummation of the Merger. We recognized compensation expense of approximately $2.1 million and $1.5 million during the nine months ended September 30, 2013 and 2012, included in operating expenses on our consolidated statements of income. We granted phantom and restricted units with a grant date fair value of approximately $5 million during the nine months ended September 30, 2013.
	Under the 2007 Equity Plan, participants who were granted restricted units could elect to have us withhold common units to satisfy minimum statutory tax withholding obligations arising in connection with the vesting of non-vested common units. Any such common units withheld were returned to the 2007 Equity Plan on the applicable vesting dates, which corresponded to the times at which income was recognized by the employee. When we withhold these common units, we were required to remit to the appropriate taxing authorities the fair value of the units withheld as of the vesting date. The number of units withheld was determined based on the closing price per common unit as reported on the NYSE on such dates. During the nine months ended September 30, 2013 and 2012, we withheld 3,341 common units and 414 common units to satisfy employee tax withholding obligations.

Transactions_With_Related_Part

Transactions With Related Parties	9 Months Ended
	Sep. 30, 2013
Transactions With Related Parties [Abstract]	'
Transactions With Related Parties	'
	12. TRANSACTIONS WITH RELATED PARTIES
	We enter into transactions with our affiliates within the ordinary course of business. Concurrent with the Merger described in Note 1. Organization and Description of Business, Quicksilver Resources, Inc. is no longer a related party. For a further discussion of our related party transactions during the three and nine months ended September 30, 2013, see Note 5. Investment in Unconsolidated Affiliate. For a description of our affiliated transactions, see our 2012 Annual Report on Form 10-K.
	Reimbursements from our affiliates were approximately $1 million and $2 million for the three and nine months ended September 30, 2013 and less than $1 million for the three and nine months ended September 30, 2012. The following table shows revenues and expenses from our affiliates for the three and nine months ended September 30, 2013 and 2012 (In millions):
		Three Months Ended				Nine Months Ended
		September 30,				September 30,
			2013		2012		2013		2012
	Operating revenues	$	24	$	28	$	74	$	87
	Operating expenses		13		5		39		15

Segment_Information

Segment Information	9 Months Ended
	Sep. 30, 2013
Segment Information [Abstract]	'
Segment Information	'
	13. SEGMENT INFORMATION
	We conduct our operations in the midstream sector with eight operating segments, four of which are reportable segments. These operating segments reflect the way we internally report the financial information used to make decisions and allocate resources in connection with our operations. We evaluate the performance of our operating segments based on EBITDA, which represents operating income plus depreciation, amortization and accretion expense and income tax expense.
	Our reportable segments reflect the primary geographic areas in which we operate and consist of Marcellus, Barnett, Fayetteville and Granite Wash, all of which are located within the United States. Our reportable segments are engaged in the gathering, processing, treating, compression, transportation and sales of natural gas and delivery of NGLs. Our Other operating segment consists of those operating segments or reporting units that did not meet quantitative reporting thresholds. In conjunction with the Merger described in Note 1, we revised our segments to reflect the new operations of the combined entities.
	For the nine months ended September 30, 2013 and 2012, one of our customers in the Barnett segment accounted for approximately 34% and 50% of our total revenues. In each of our Marcellus and Granite Wash segments, one customer accounted for approximately 21% and 10%, respectively, of our revenues for the nine months ended September 30, 2013. In addition, in our Fayetteville segment, one customer accounted for approximately 10% of our total revenues for the nine months ended September 30, 2012.
	The following table is a reconciliation of net income to EBITDA (In thousands):
			Three Months Ended				Nine Months Ended
			September 30,				September 30,
			2013		2012		2013		2012
	Net income	$	6,388	$	14,381	$	20,216	$	30,984
	Add:
	Interest and debt expense		11,625		8,905		34,260		25,425
	Income tax expense		347		306		1,024		884
	Depreciation, amortization and accretion expense		14,557		11,568		49,618		35,909
	EBITDA	$	32,917	$	35,160	$	105,118	$	93,202
	The following tables summarize the reportable segment data for the three and nine months ended September 30, 2013 and 2012 (In thousands):
		Three Months Ended September 30, 2013
									Granite
			Marcellus		Barnett		Fayetteville		Wash		Other			Corporate			Total
	Operating revenues	$	15,914	$	8,257	$	7,799	$	12,733	$	2,288		$	—		$	46,991
	Operating revenues—related party		74		23,624		—		449		—			—			24,147
	Product purchases		—		157		249		3,872		1,017			—			5,295
	Product purchases—related party		—		—		—		7,556		—			—			7,556
	Operations and maintenance
	expense		2,832		7,717		2,303		810		1,233			—			14,895
	General and administrative
	expense		—		—		—		—		—			10,367			10,367
	Goodwill impairment		—		—		—		—		(4,053	)		—			(4,053	)
	Gain on sale of asset		—		—		—		4,392		—			—			4,392
	Loss from unconsolidated affiliate		—		—		—		—		(447	)		—			(447	)
	EBITDA	$	13,156	$	24,007	$	5,247	$	5,336	$	(4,462	)	$	(10,367	)	$	32,917
	Goodwill	$	8,618	$	—	$	76,767	$	14,211	$	—		$	—		$	99,596
	Total assets	$	672,627	$	604,569	$	297,064	$	77,719	$	204,053		$	27,951		$	1,883,983
	Capital expenditures	$	71,124	$	156	$	4,106	$	3,958	$	4,794		$	161		$	84,299
		Three Months Ended September 30, 2012
									Granite
			Marcellus		Barnett		Fayetteville		Wash		Other		Corporate			Total
	Operating revenues	$	7,976	$	5,390	$	7,174	$	10,702	$	3,815	$	—		$	35,057
	Operating revenues—related party		—		27,956		—		—		—		—			27,956
	Product purchases		—		60		137		9,481		663		—			10,341
	Operations and maintenance
	expense		815		6,963		1,855		560		749		—			10,942
	General and administrative
	expense		—		—		—		—		—		6,570			6,570
	EBITDA	$	7,161	$	26,323	$	5,182	$	661	$	2,403	$	(6,570	)	$	35,160
	Goodwill	$	—	$	—	$	76,767	$	14,211	$	4,053	$	—		$	95,031
	Total assets	$	396,634	$	619,768	$	304,669	$	77,611	$	83,701	$	17,097		$	1,499,480
	Capital expenditures	$	4,540	$	4,719	$	1,086	$	448	$	955	$	225		$	11,973
		Nine Months Ended September 30, 2013
									Granite
			Marcellus		Barnett		Fayetteville		Wash		Other			Corporate			Total
	Operating revenues	$	45,497	$	26,647	$	21,383	$	39,368	$	7,441		$	—		$	140,336
	Operating revenues—related party		162		72,856		—		1,299		—			—			74,317
	Product purchases		—		558		732		13,936		2,971			—			18,197
	Product purchases—related party		—		—		—		22,191		—			—			22,191
	Operations and maintenance
	expense		7,774		21,284		6,747		2,103		2,595			—			40,503
	General and administrative
	expense		—		—		—		—		—			28,536			28,536
	Goodwill impairment		—		—		—		—		(4,053	)		—			(4,053	)
	Gain on sale of asset		—		—		—		4,392		—			—			4,392
	Loss from unconsolidated affiliate		—		—		—		—		(447	)		—			(447	)
	EBITDA	$	37,885	$	77,661	$	13,904	$	6,829	$	(2,625	)	$	(28,536	)	$	105,118
	Goodwill	$	8,618	$	—	$	76,767	$	14,211	$	—		$	—		$	99,596
Total assets	$	672,627	$	604,569	$	297,064	$	77,719	$	204,053		$	27,951		$	1,883,983
Capital expenditures	$	135,845	$	8,925	$	6,818	$	6,481	$	5,954		$	573		$	164,596
	Nine Months Ended September 30, 2012
								Granite
		Marcellus		Barnett		Fayetteville		Wash		Other		Corporate			Total
Operating revenues	$	15,003	$	12,053	$	20,368	$	28,021	$	9,791	$	—		$	85,236
Operating revenues—related party		—		86,739		—		—		—		—			86,739
Product purchases		—		60		343		24,514		1,838		—			26,755
Operations and maintenance
expense		1,328		18,438		6,399		1,619		2,269		—			30,053
General and administrative
expense		—		—		—		—		—		21,965			21,965
EBITDA	$	13,675	$	80,294	$	13,626	$	1,888	$	5,684	$	(21,965	)	$	93,202
Goodwill	$	—	$	—	$	76,767	$	14,211	$	4,053	$	—		$	95,031
Total assets	$	396,634	$	619,768	$	304,669	$	77,611	$	83,701	$	17,097		$	1,499,480
Capital expenditures	$	5,378	$	10,718	$	10,040	$	2,411	$	5,140	$	659		$	34,346

Condensed_Consolidating_Financ

Condensed Consolidating Financial Statements	9 Months Ended
	Sep. 30, 2013
Condensed Consolidating Financial Statements [Abstract]	'
Condensed Consolidating Financial Statements	'
	14. CONDENSED CONSOLIDATING FINANCIAL STATEMENTS
	In conjunction with the Merger discussed in Note 1. Organization and Description of Business, CMLP entered into a supplemental indenture governing the 7.75% Senior Notes. Pursuant to the supplemental indenture, Crestwood Midstream Partners LP (formerly NRGM) and Crestwood Midstream Finance Corp (formerly NRGM Finance Corp.), which we refer to together as the Successor Issuers, have unconditionally assumed all of the obligations under the 7.75% Senior Notes due April 2019. In addition, certain subsidiaries have entered into financial guarantees pursuant to which they unconditionally guarantee the obligations under the indenture and Senior Notes. Prior to the Merger, the CMLP Credit Facility and our Senior Notes were fully and unconditionally guaranteed, jointly and severally, by CMLP's present and future direct and indirect 100% owned subsidiaries (the Guarantor Subsidiaries), except for Crestwood Niobrara and CMM and its consolidated subsidiaries (the Non-Guarantor Subsidiaries). CMLP (Issuer) issued the Senior Notes together with Crestwood Midstream Finance Corporation (Co-Issuer). The Co-Issuer is our 100% owned subsidiary and has no material assets, operations, revenues or cash flows other than those that were related to its service as co-issuer of our Senior Notes. Accordingly, it had no ability to service obligations on our debt securities.
	The following reflects condensed consolidating financial information of the Issuer, Co-Issuer, Guarantor Subsidiaries, Non-Guarantor Subsidiaries, eliminating entries to combine the entities and our consolidated results as of September 30, 2013 and December 31, 2012 and for the three and nine months ended September 30, 2013 and 2012.
		For the Three Months Ended September 30, 2013
								Guarantor		Non-Guarantor
			Issuer			Co-Issuer		Subsidiaries		Subsidiaries			Eliminations			Consolidated
		(In thousands)
	Operating revenues	$	—		$	—	$	55,457	$	15,681		$	—		$	71,138
	Operating expenses		245			—		46,077		6,348			—			52,670
	Goodwill impairment		—			—		(4,053	)	—			—			(4,053	)
	Gain on sale of asset		—			—		4,392		—			—			4,392
	Operating income (loss)		(245	)		—		9,719		9,333			—			18,807
	Loss from unconsolidated affiliate		—			—		—		(447	)		—			(447	)
	Interest and debt expense		(10,518	)		—		42		(1,149	)		—			(11,625	)
	Income (loss) before income tax		(10,763	)		—		9,761		7,737			—			6,735
	Income tax expense		—			—		347		—			—			347
	Income (loss) before earnings from
	consolidated subsidiaries		(10,763	)		—		9,414		7,737			—			6,388
	Earnings (loss) from consolidated
	subsidiaries		17,151			—		—		—			(17,151	)		—
	Net income (loss)		6,388			—		9,414		7,737			(17,151	)		6,388
	Net income attributable to noncontrolling
	interest		—			—		—		1,923			—			1,923
	Net income (loss) attributable to
	Crestwood Midstream Partners LP		6,388			—		9,414		5,814			(17,151	)		4,465
	General partner's interest in net income		81			—		—		—			—			81
	Limited partner's interest in net income
	(loss)	$	6,307		$	—	$	9,414	$	5,814		$	(17,151	)	$	4,384
		For the Three Months Ended September 30, 2012
								Guarantor			Non-Guarantor
			Issuer			Co-Issuer		Subsidiaries			Subsidiaries			Eliminations			Consolidated
		(In thousands)
	Operating revenues	$	—		$	—	$	55,037		$	7,976		$	—		$	63,013
	Operating expenses		179			—		37,009			2,233			—			39,421
	Operating income (loss)		(179	)		—		18,028			5,743			—			23,592
	Interest and debt expense		(8,147	)		—		(55	)		(703	)		—			(8,905	)
	Income (loss) before income tax		(8,326	)		—		17,973			5,040			—			14,687
	Income tax expense		—			—		306			—			—			306
	Income (loss) before earnings from
	consolidated subsidiaries		(8,326	)		—		17,667			5,040			—			14,381
	Earnings (loss) from consolidated
	subsidiaries		22,707			—		—			—			(22,707	)		—
	Net income (loss)		14,381			—		17,667			5,040			(22,707	)		14,381
	General partner's interest in net income		7,516			—		—			—			—			7,516
	Limited partner's interest in net income
	(loss)	$	6,865		$	—	$	17,667		$	5,040		$	(22,707	)	$	6,865
		For the Nine Months Ended September 30, 2013
								Guarantor			Non-Guarantor
			Issuer			Co-Issuer		Subsidiaries			Subsidiaries			Eliminations			Consolidated
		(In thousands)
	Operating revenues	$	—		$	—	$	169,389		$	45,264		$	—		$	214,653
	Operating expenses		640			—		135,891			22,514			—			159,045
	Goodwill impairment		—			—		(4,053	)		—			—			(4,053	)
	Gain on sale of asset		—			—		4,392			—			—			4,392
	Operating income (loss)		(640	)		—		33,837			22,750			—			55,947
	Loss from unconsolidated affiliate		—			—		—			(447	)		—			(447	)
	Interest and debt expense		(30,731	)		—		(91	)		(3,438	)		—			(34,260	)
	Income (loss) before income tax		(31,371	)		—		33,746			18,865			—			21,240
	Income tax expense		—			—		1,024			—			—			1,024
	Income (loss) before earnings from
	consolidated subsidiaries		(31,371	)		—		32,722			18,865			—			20,216
	Earnings (loss) from consolidated
	subsidiaries		51,587			—		—			—			(51,587	)		—
Net income (loss)		20,216			—		32,722			18,865			(51,587	)		20,216
Net income attributable to noncontrolling
interest		—			—		—			1,923			—			1,923
Net income (loss) attributable to
Crestwood Midstream Partners LP		20,216			—		32,722			16,942			(51,587	)		18,293
General partner's interest in net income		10,474			—		—			—			—			10,474
Limited partner's interest in net income
(loss)	$	9,742		$	—	$	32,722		$	16,942		$	(51,587	)	$	7,819
	For the Nine Months Ended September 30, 2012
							Guarantor			Non-Guarantor
		Issuer			Co-Issuer		Subsidiaries			Subsidiaries			Eliminations			Consolidated
	(In thousands)
Operating revenues	$	—		$	—	$	156,972		$	15,003		$	—		$	171,975
Operating expenses		397			—		106,961			7,324			—			114,682
Operating income (loss)		(397	)		—		50,011			7,679			—			57,293
Interest and debt expense		(23,896	)		—		(149	)		(1,380	)		—			(25,425	)
Income (loss) before income tax		(24,293	)		—		49,862			6,299			—			31,868
Income tax expense		—			—		884			—			—			884
Income (loss) before earnings from
consolidated subsidiaries		(24,293	)		—		48,978			6,299			—			30,984
Earnings (loss) from consolidated
subsidiaries		55,277			—		—			—			(55,277	)		—
Net income (loss)		30,984			—		48,978			6,299			(55,277	)		30,984
General partner's interest in net income		15,038			—		—			—			—			15,038
Limited partner's interest in net income
(loss)	$	15,946		$	—	$	48,978		$	6,299		$	(55,277	)	$	15,946
	As of September 30, 2013
						Guarantor	Non-Guarantor
		Issuer		Co-Issuer		Subsidiaries	Subsidiaries			Eliminations			Consolidated
	(In thousands)
ASSETS
Current assets
Cash and cash equivalents	$	4,506	$	—	$	—	$	1,162	$	—		$	5,668
Accounts receivable		1,626		—		15,024		11,016		—			27,666
Accounts receivable—related
party		399,755		1		23,783		12		(399,501	)		24,050
Insurance receivable		—		—		3,072		—		—			3,072
Prepaid expenses and other		174		—		595		22		—			791
Total current assets		406,061		1		42,474		12,212		(399,501	)		61,247
Investment in unconsolidated
affiliate		—		—		—		127,651		—			127,651
Investment in consolidated
affiliates		1,186,766		—		—		—		(1,186,766	)		—
Property, plant and equipment—net		3,069		—		861,728		280,075		—			1,144,872
Intangible assets—net		—		—		112,178		316,702		—			428,880
Goodwill		—		—		90,978		8,618		—			99,596
Deferred financing costs, net		16,290		—		—		4,429		—			20,719
Other assets		25		—		993		—		—			1,018
Total assets	$	1,612,211	$	1	$	1,108,351	$	749,687	$	(1,586,267	)	$	1,883,983
LIABILITIES AND PARTNERS'
CAPITAL/MEMBERS' EQUITY
Current liabilities
Accrued additions to property,
plant and equipment	$	—	$	—	$	24,786	$	16,462	$	—		$	41,248
Capital leases		389		—		2,556		—		—			2,945
Deferred revenue		—		—		—		2,426		—			2,426
Accounts payable—related party		1,887		—		401,460		671		(399,501	)		4,517
Accounts payable, accrued
expenses and other
liabilities		25,229		—		9,180		6,626		—			41,035
Total current liabilities		27,505		—		437,982		26,185		(399,501	)		92,171
Long-term debt		707,486		—		—		191,900		—			899,386
Long-term capital leases		679		—		573		—		—			1,252
Asset retirement obligations		—		—		13,759		874		—			14,633
Partners'/members' equity		876,541		1		656,037		530,728		(1,186,766	)		876,541
Total liabilities and
partners'
capital/members'
equity	$	1,612,211	$	1	$	1,108,351	$	749,687	$	(1,586,267	)	$	1,883,983
	As of December 31, 2012
						Guarantor		Non-Guarantor
		Issuer		Co-Issuer		Subsidiaries		Subsidiaries		Eliminations			Consolidated
	(In thousands)
ASSETS
Current assets
Cash and cash equivalents	$	21	$	—	$	—	$	90	$	—		$	111
Accounts receivable		608		—		14,515		6,513		—			21,636
Accounts receivable—related
party		366,405		1		22,587		—		(365,238	)		23,755
Insurance receivable		—		—		2,920		—		—			2,920
Prepaid expenses and other		584		—		1,357		—		—			1,941
Total current assets		367,618		1		41,379		6,603		(365,238	)		50,363
Investment in consolidated
affiliates		1,041,936		—		—		—		(1,041,936	)		—
Property, plant and equipment—net		8,519		—		775,852		155,475		—			939,846
Intangible assets—net		—		—		163,021		338,359		—			501,380
Goodwill		—		—		95,031		—		—			95,031
Deferred financing costs, net		17,149		—		—		5,379		—			22,528
Other assets		20		—		1,301		—		—			1,321
Total assets	$	1,435,242	$	1	$	1,076,584	$	505,816	$	(1,407,174	)	$	1,610,469
LIABILITIES AND PARTNERS'
CAPITAL/MEMBERS' EQUITY
Current liabilities
Accrued additions to property,
plant and equipment	$	—	$	—	$	3,829	$	5,384	$	—		$	9,213
Capital leases		429		—		3,433		—		—			3,862
Deferred revenue		—		—		—		2,634		—			2,634
Accounts payable—related party		536		—		367,682		108		(365,238	)		3,088
Accounts payable, accrued
expenses and other
liabilities		15,547		—		11,876		2,294		—			29,717
Total current liabilities		16,512		—		386,820		10,420		(365,238	)		48,514
Long-term debt		558,161		—		—		127,000		—			685,161
Long-term capital leases		960		—		2,201		—		—			3,161
Asset retirement obligations		—		—		13,188		836		—			14,024
Partners'/members' equity		859,609		1		674,375		367,560		(1,041,936	)		859,609
Total liabilities and
partners'
capital/members'
equity	$	1,435,242	$	1	$	1,076,584	$	505,816	$	(1,407,174	)	$	1,610,469
	For the Nine Months Ended September 30, 2013
							Guarantor		Non-Guarantor
		Issuer			Co-Issuer		Subsidiaries		Subsidiaries				Eliminations			Consolidated
	(In thousands)
Net cash provided by (used in)
operating activities	$	(18,629	)	$	—	$	102,271		$	31,506		$	(33,795	)	$	81,353
Investing activities:
Capital expenditures		(573	)		—		(52,464	)		(111,559	)		—			(164,596	)
Capital contribution to
consolidated affiliate		(82,025	)		—		—			—			82,025			—
Proceeds from sale of asset		—			—		11,000			—			—			11,000
Investment in unconsolidated
affiliate		—			—		—			(128,098	)		—			(128,098	)
Other		—			—		—			20			—			20
Change in advances to affiliates,
net		57,413			—		—			—			(57,413	)		—
Net cash provided by (used in)
investing activities		(25,185	)		—		(41,464	)		(239,637	)		24,612			(281,674	)
Financing activities:
Proceeds from credit facilities		343,500			—		—			139,900			—			483,400
Repayments of credit facilities		(194,000	)		—		—			(75,000	)		—			(269,000	)
Payments on capital leases		(321	)		—		(2,694	)		—			—			(3,015	)
Deferred financing costs paid		(85	)		—		—			—			—			(85	)
Proceeds from issuance of
common units, net		118,562			—		—			—			—			118,562
Proceeds from issuance of
preferred equity of subsidiary		—			—		—			96,073			—			96,073
Contributions received		—			—		—			82,025			(82,025	)		—
Distributions to General Partner
for additional interest in CMM		(129,000	)		—		—			—			—			(129,000	)
Distributions paid		(90,357	)		—		—			(33,795	)		33,795			(90,357	)
Change in advances from
affiliates, net		—			—		(57,413	)		—			57,413			—
Taxes paid for equity-based
compensation vesting		—			—		(700	)		—			—			(700	)
Net cash provided by (used in)
financing activities		48,299			—		(60,807	)		209,203			9,183			205,878
Change in cash and cash equivalents		4,485			—		—			1,072			—			5,557
Cash and cash equivalents at beginning
of period		21			—		—			90			—			111
Cash and cash equivalents at end of
period	$	4,506		$	—	$	—		$	1,162		$	—		$	5,668
	For the Nine Months Ended September 30, 2012
							Guarantor		Non-Guarantor
		Issuer			Co-Issuer		Subsidiaries		Subsidiaries				Eliminations			Consolidated
	(In thousands)
Net cash provided by (used in)
operating activities	$	(16,014	)	$	—	$	86,153		$	9,934		$	(2,205	)	$	77,868
Investing activities:
Acquisitions, net of cash
acquired		—			—		(87,269	)		(381,718	)		—			(468,987	)
Capital expenditures		(659	)		—		(28,309	)		(5,378	)		—			(34,346	)
Acquisition of interests in
CMM		(131,250	)		—		—			—			131,250			—
Capital contribution to
consolidated affiliate		1,647			—		—			—			(1,647	)		—
Change in advances to affiliates,
net		(31,730	)		—		—			—			31,730			—
Net cash provided by (used in)
investing activities		(161,992	)		—		(115,578	)		(387,096	)		161,333			(503,333	)
Financing activities:
Proceeds from credit facilities		350,200			—		—			27,500			—			377,700
Repayments of credit facilities		(329,500	)		—		—			(8,000	)		—			(337,500	)
Payments on capital leases		(256	)		—		(1,899	)		—			—			(2,155	)
Deferred financing costs paid		(161	)		—		—			(6,328	)		—			(6,489	)
Proceeds from issuance of
common units, net		217,508			—		—			—			—			217,508
Contributions received		5,930			—		—			375,000			(131,250	)		249,680
Distributions paid		(66,500	)		—		—			(11,005	)		3,852			(73,653	)
Change in advances from affiliate,
net		—			—		31,730			—			(31,730	)		—
Taxes paid for equity-based
compensation vesting		—			—		(406	)		—			—			(406	)
Net cash provided by (used in)
financing activities		177,221			—		29,425			377,167			(159,128	)		424,685
Change in cash and cash equivalents		(785	)		—		—			5			—			(780	)
Cash and cash equivalents at beginning
of period		797			—		—			—			—			797
Cash and cash equivalents at end of
period	$	12		$	—	$	—		$	5		$	—		$	17

Subsequent_Events

Subsequent Events	9 Months Ended
	Sep. 30, 2013
Subsequent Events [Abstract]	'
Subsequent Event	'
	15. SUBSEQUENT EVENTS
	As discussed in Note 1. Organization and Description of Business, on October 7, 2013, CMLP merged with and into NRGM with NRGM continuing as the surviving entity. The Merger was accounted for as a reverse acquisition of NRGM under the purchase method of accounting in accordance with the accounting standards related to business combinations. The accounting for a reverse merger results in the legal acquiree (CMLP) being the acquirer for accounting purposes. Therefore, CMLP will account for the merger as if CMLP acquired NRGM. For additional information related to the Merger, See Notes 7, 9, 11, 12 and 13.
	The following table represents the pro forma consolidated statements of operations as if the reverse acquisition had been included in the consolidated results of CMLP on January 1, 2012 (In millions, except per unit data):
		Three Months Ended				Nine Months Ended
		September 30,				September 30,
			2013		2012		2013		2012
	Revenues	$	140	$	114	$	418	$	318
	Net income (loss)	$	12	$	24	$	40	$	63
	Net income (loss) per limited partner unit:
	Basic	$	0.02	$	0.15	$	0.17	$	0.4
	Diluted:	$	0.02	$	0.15	$	0.17	$	0.4

Basis_Of_Presentation_And_Summ1

Basis Of Presentation And Summary Of Significant Accounting Policies (Policy)	9 Months Ended
	Sep. 30, 2013
Basis Of Presentation And Summary Of Significant Accounting Policies [Abstract]	'
Basis Of Presentation	'
	Basis of Presentation
	We prepared this Quarterly Report on Form 10-Q under the rules and regulations of the SEC and in accordance with accounting principles generally accepted in the United States of America (GAAP) for interim consolidated financial statements. Accordingly, they do not include all of the disclosures required by GAAP.
	On March 26, 2012, Crestwood Holdings contributed approximately $244 million for a 65% membership interest in Crestwood Marcellus Midstream LLC (CMM) and we contributed approximately $131 million for a 35% membership interest in CMM. On January 8, 2013, we acquired Crestwood Holdings' 65% membership interest in CMM and as a result, we now own 100% of CMM and have the ability to control the operating and financial decisions of CMM. We accounted for this transaction as a reorganization of entities under common control and the accounting standards related to such transactions require us to retroactively adjust our historical results. Accordingly, the consolidated balance sheets reflect the historical carrying value of CMM's assets and liabilities. Earnings related to the recast of our historical results due to the acquisition of the 65% membership interest in CMM were allocated to the General Partner. As a result, there was no impact to our 2012 reported basic or diluted earnings per limited partner unit. We funded the purchase price for the 65% membership interest in CMM of approximately $258 million through $129 million of borrowings under our CMLP credit facility, the issuance of 6,190,469 Class D units, representing limited partner interests in us to Crestwood Holdings, and the issuance of 133,060 general partner units to our General Partner. For accounting purposes, because of the consolidation of CMM, we reflected the $129 million cash paid to acquire the 65% interest in CMM and the issuance of Class D units as a reduction of our General Partner's capital.
	You should read this Quarterly Report on Form 10-Q along with our Form 8-K filed with the SEC on May 10, 2013. The financial statements as of September 30, 2013 and for the three and nine months ended September 30, 2013 and 2012 are unaudited. The consolidated balance sheet as of December 31, 2012, was derived from the audited balance sheet filed in our Form 8-K filed with the SEC on May 10, 2013. In management's opinion, all necessary adjustments to fairly present our results of operations, financial position and cash flows for the periods presented have been made and all such adjustments are of a normal and recurring nature. Information for interim periods may not be indicative of our operating results for the entire year. Our disclosures in this Form 10-Q are an update to those provided in our Form 8-K filed with the SEC on May 10, 2013.
Revenues	'
	Revenues
	Our revenues are generated from the gathering, compression and processing of natural gas from producers predominately under fee-based contracts. Our gathering revenues relate to contracts pursuant to which we both transport and compress natural gas based on the volumes that flow through our systems and are not directly dependent on commodity prices. Compression revenues relate to contracts under which we solely provide compression services or contracts under which we charge a compression services fee that is separate from other services provided under our contracts. For the three and nine months ended September 30, 2013, our compression revenues were entirely comprised of services provided under contracts obtained in the E. Marcellus Asset Company, LLC (EMAC) acquisition (See Note 3). The majority of our processing revenues are generated from contracts under which we charge a fixed-fee. Under certain of our processing contracts, raw natural gas is gathered, processed and sold at published index prices. Producers are paid based on an agreed percentage of the residue gas and NGLs multiplied by index prices or the actual sale prices.
Goodwill	'
	Goodwill
	Our goodwill represents consideration paid in excess of the fair value of the identifiable assets acquired in a business combination. We have assigned our goodwill to four of our operating segments (Marcellus, Granite Wash, Fayetteville and Haynesville) which, based on management's judgment, we also consider reporting units for goodwill assessment purposes.
	We evaluate goodwill for impairment, at a minimum, annually on December 31, or whenever events or changes indicate that it is more likely than not that the fair value of a reporting unit could be less than its carrying amount. This evaluation requires us to compare the fair value of each of the three reporting units above to its carrying value (including goodwill). If the fair value exceeds the carry amount, goodwill of the reporting unit is not considered impaired.
	We estimate the fair value of our reporting units based on a number of factors, including the potential value we would receive if we sold the reporting unit, discount rates and projected cash flows. Projected cash flows of the reporting unit are generally based on current and anticipated future market conditions, which require significant judgment to make projections and assumptions about pricing, demand, competition, operating costs, legal and regulatory issues and other factors that may extend many years into the future and are often outside of our control. Due to the imprecise nature of these projections and assumptions, actual results can and often do, differ from our estimates.
	During the three months ended September 30, 2013, we recorded an impairment of goodwill of approximately $4 million on our Haynesville/Bossier Shale system as a result of a decrease in anticipated revenues to be generated from those operations due primarily to our inability to renew and extend a significant revenue contract that expired in mid-2013.
Investment In Unconsolidated Affiliate	'
	Investment in Unconsolidated Affiliate
	We apply the equity method of accounting where we can exert significant influence over, but do not control or direct, the policies, decisions or activities of the entity. We use the cost method of accounting where we are unable to exert significant influence over the entity. The Financial Accounting Standards Board's accounting standards related to equity method investments and joint ventures requires entities to periodically review their equity method investments to determine whether current events or circumstances indicate that the carrying value of the equity method investment may be impaired. We evaluate our equity method investment for impairment when there are indicators of impairment. If indicators suggest impairment we will perform an impairment test to assess whether an adjustment is necessary. The impairment test considers whether the fair value of our equity method investment has declined and if any such decline is other than temporary. If a decline in fair value is determined to be other than temporary, the investment's carrying value is written down to fair value.

Acquisitions_And_Divestitures_

Acquisitions And Divestitures (Tables)	9 Months Ended
	Sep. 30, 2013
Antero Acquisition [Member]	'
Schedule Of Purchase Price Allocation	'
	Cash	$	381,718
	Total purchase price	$	381,718
	Purchase price allocation:
	Property, plant and equipment	$	90,562
	Intangible assets		291,218
	Total assets	$	381,780
	Asset retirement obligation	$	62
	Total liabilities	$	62
	Total	$	381,718
EMAC Acquisition [Member]	'
Schedule Of Purchase Price Allocation	'
	Cash	$	94,979
	Total purchase price	$	94,979
	Purchase price allocation:
	Property, plant and equipment	$	53,357
	Intangible assets		33,909
	Goodwill		8,618
	Total assets	$	95,884
	Asset retirement obligation	$	755
	Environmental liability		150
	Total liabilities	$	905
	Total	$	94,979
Devon Acquisition [Member]	'
Schedule Of Purchase Price Allocation	'
	Cash	$	87,943
	Total purchase price	$	87,943
	Purchase price allocation:
	Property, plant and equipment	$	88,626
	Total assets	$	88,626
	Asset retirement obligation	$	483
	Environmental liability		200
	Total liabilities	$	683
	Total	$	87,943

Earnings_Per_Limited_Partner_U1

Earnings Per Limited Partner Unit And Distributions (Tables)	9 Months Ended
	Sep. 30, 2013
Earnings Per Limited Partner Unit And Distributions [Abstract]	'
Allocation Of Net Income To General Partner And Limited Partners	'
			Three Months Ended						Nine Months Ended
			September 30,						September 30,
			2013			2012			2013			2012
			(In thousands)
	Net income attributable to CMLP	$	4,465		$	14,381		$	18,293		$	30,984
	General Partner's incentive distributions (1)		—			(4,101	)		(10,140	)		(10,636	)
	Net income attributable to CMLP after incentive distributions		4,465			10,280			8,153			20,348
	General Partner's interest in net income attributable to CMLP
	after incentive distributions		(81	)		(3,415	)		(334	)		(4,402	)
	Limited Partners' interest in net income attributable to CMLP
	after distributions	$	4,384		$	6,865		$	7,819		$	15,946
	(1) As a result of the Merger on October 7, 2013 described in Note 1. Organization and Description of Business, there were no distributions to CMLP's unitholders for the three months ended September 30, 2013; therefore, our General Partner did not receive any incentive distributions attributable to that period.
Schedule Of Reconciliation Of Earnings Per Share	'
	Three Months Ended September 30,
			2013		2012
	Limited partners' interest in net income attributable to CMLP	$	4,384	$	6,865
	Weighted-average limited partner units—basic (1)		60,188		46,564
	Effect of dilutive units		260		203
	Weighted-average limited partner units—diluted (1)		60,448		46,767
	Basic and diluted net income attributable to CMLP per limited
	partner unit	$	0.07	$	0.15
	(1) The three months ended September 30, 2013 includes 6,421,641 Class D units. The three months ended September 30, 2012 includes 6,929,763 Class C units.
	Nine Months Ended September 30,
			2013		2012
	Limited partners' interest in net income attributable to CMLP	$	7,819	$	15,946
	Weighted-average limited partner units—basic (1)		58,339		44,206
	Effect of dilutive units		269		189
	Weighted-average limited partner units—diluted (1)		58,608		44,395
	Basic and diluted net income attributable to CMLP per limited
	partner unit	$	0.13	$	0.36
	(1) The nine months ended September 30, 2013 includes 8,536,178 Class C and Class D units. The nine months ended September 30, 2012 includes 6,795,130 Class C units.
Schedule Of Distributions Made To Partners	'
					Distributions Paid
					Limited Partner						General Partner
								Paid-In-Kind		Paid-In-Kind		Cash paid		Paid-In-Kind		Paid-In-Kind
								Value to		Value to		to General		Value to		Value to
		Attributable to the Per Unit				Cash paid		Class C		Class D		Partner		Class C		Class D		Total		Total
	Payment Date	Quarter Ended		Distribution		to common(1)		unitholders		unitholder		and IDR		unitholder		unitholder		Cash		Distribution
	2013
	August 9,
	2013	30-Jun-13	$	0.51	$	27.4	$	—	$	3.2	$	5.2	$	—	$	0.5	$	32.6	$	36.3
	May 10,
	2013	31-Mar-13	$	0.51	$	27.4	$	—	$	3.2	$	5.2	$	—	$	0.5	$	32.6	$	36.3
	February 12,
	2013	31-Dec-12	$	0.51	$	21	$	3.7	$	—	$	4.1	$	0.6	$	—	$	25.1	$	29.4
	2012
	November 9,
	2012	30-Sep-12	$	0.51	$	21	$	3.5	$	—	$	4.1	$	0.6	$	—	$	25.1	$	29.2
	August 10,
	2012	30-Jun-12	$	0.5	$	20.6	$	3.4	$	—	$	3.7	$	0.5	$	—	$	24.3	$	28.2
	May 11,
	2012	31-Mar-12	$	0.5	$	18.2	$	3.4	$	—	$	3.3	$	0.5	$	—	$	21.5	$	25.4
	February 10,
	2012	31-Dec-11	$	0.49	$	17.9	$	3.2	$	—	$	2.8	$	0.5	$	—	$	20.7	$	24.4
	(1) Distributions for the quarters ended June 30, 2012 and September 30, 2012 exclude approximately $3 million and $4 million paid by CMM to Crestwood Holdings.

Financial_Instruments_Tables

Financial Instruments (Tables)	9 Months Ended
	Sep. 30, 2013
Financial Instruments [Abstract]	'
Schedule Of Carrying Values And Estimated Fair Values Of Senior Notes	'
			30-Sep-13				31-Dec-12
			Carrying		Fair		Carrying		Fair
			Amount		Value		Amount		Value
	Senior Notes	$	351	$	369	$	351	$	365
Schedule Of Debt	'
			September 30,		December 31,
			2013		2012
	CMM Credit Facility, due March 2017	$	191,900	$	127,000
	CMLP Credit Facility, due November 2017		356,200		206,700
	Senior Notes, due April 2019		350,000		350,000
			898,100		683,700
	Plus: Unamortized premium on Senior Notes		1,286		1,461
	Total long-term debt	$	899,386	$	685,161

Accounts_Payable_Accrued_Expen1

Accounts Payable, Accrued Expenses And Other Liabilities (Tables)	9 Months Ended
	Sep. 30, 2013
Accounts Payable, Accrued Expenses And Other Liabilities [Abstract]	'
Schedule Of Accounts Payable And Other Liabilities	'
		September 30,		December 31,
		2013		2012
	Accrued expenses	$	11,305	$	9,608
	Accrued property taxes		5,843		5,638
	Accrued product purchases payable		1,818		2,450
	Tax payable		1,353		2,159
	Interest payable		14,054		7,505
	Accounts payable		6,653		2,278
	Other		9		79
	Total accounts payable, accrued expenses and other liabilities	$	41,035	$	29,717

Equity_Plan_Tables

Equity Plan (Tables)	9 Months Ended
	Sep. 30, 2013
Equity Plan [Abstract]	'
Schedule Of Phantom And Restricted Unit Activity	'
		Payable In Cash				Payable In Units
					Weighted-				Weighted-
					Average Grant				Average Grant
					Date Fair				Date Fair
		Units			Value	Units			Value
	Unvested—January 1, 2013	8,312		$	26.45	221,992		$	28.35
	Vested—phantom units	(3,013	)	$	27.22	(71,006	)	$	28.7
	Vested—restricted units	—			—	(11,349	)	$	26.4
	Granted—phantom units	—			—	161,807		$	24.33
	Granted—restricted units	—			—	27,900		$	24.86
	Canceled—phantom units	(354	)	$	25.81	(7,114	)	$	27.96
	Unvested—September 30, 2013	4,945		$	26.02	322,230		$	26.01

Transactions_With_Related_Part1

Transactions With Related Parties (Tables)	9 Months Ended
	Sep. 30, 2013
Transactions With Related Parties [Abstract]	'
Schedule Of Revenues, Expenses And Reimbursements From Affiliates	'
		Three Months Ended				Nine Months Ended
		September 30,				September 30,
			2013		2012		2013		2012
	Operating revenues	$	24	$	28	$	74	$	87
	Operating expenses		13		5		39		15

Segment_Information_Tables

Segment Information (Tables)	9 Months Ended
	Sep. 30, 2013
Segment Information [Abstract]	'
Reconciliation Of Net Income To EBITDA	'
			Three Months Ended				Nine Months Ended
			September 30,				September 30,
			2013		2012		2013		2012
	Net income	$	6,388	$	14,381	$	20,216	$	30,984
	Add:
	Interest and debt expense		11,625		8,905		34,260		25,425
	Income tax expense		347		306		1,024		884
	Depreciation, amortization and accretion expense		14,557		11,568		49,618		35,909
	EBITDA	$	32,917	$	35,160	$	105,118	$	93,202
Schedule Of Reportable Segment Data	'
		Three Months Ended September 30, 2013
									Granite
			Marcellus		Barnett		Fayetteville		Wash		Other			Corporate			Total
	Operating revenues	$	15,914	$	8,257	$	7,799	$	12,733	$	2,288		$	—		$	46,991
	Operating revenues—related party		74		23,624		—		449		—			—			24,147
	Product purchases		—		157		249		3,872		1,017			—			5,295
	Product purchases—related party		—		—		—		7,556		—			—			7,556
	Operations and maintenance
	expense		2,832		7,717		2,303		810		1,233			—			14,895
	General and administrative
	expense		—		—		—		—		—			10,367			10,367
	Goodwill impairment		—		—		—		—		(4,053	)		—			(4,053	)
	Gain on sale of asset		—		—		—		4,392		—			—			4,392
	Loss from unconsolidated affiliate		—		—		—		—		(447	)		—			(447	)
	EBITDA	$	13,156	$	24,007	$	5,247	$	5,336	$	(4,462	)	$	(10,367	)	$	32,917
	Goodwill	$	8,618	$	—	$	76,767	$	14,211	$	—		$	—		$	99,596
	Total assets	$	672,627	$	604,569	$	297,064	$	77,719	$	204,053		$	27,951		$	1,883,983
	Capital expenditures	$	71,124	$	156	$	4,106	$	3,958	$	4,794		$	161		$	84,299
		Three Months Ended September 30, 2012
									Granite
			Marcellus		Barnett		Fayetteville		Wash		Other		Corporate			Total
	Operating revenues	$	7,976	$	5,390	$	7,174	$	10,702	$	3,815	$	—		$	35,057
	Operating revenues—related party		—		27,956		—		—		—		—			27,956
	Product purchases		—		60		137		9,481		663		—			10,341
	Operations and maintenance
	expense		815		6,963		1,855		560		749		—			10,942
	General and administrative
	expense		—		—		—		—		—		6,570			6,570
	EBITDA	$	7,161	$	26,323	$	5,182	$	661	$	2,403	$	(6,570	)	$	35,160
	Goodwill	$	—	$	—	$	76,767	$	14,211	$	4,053	$	—		$	95,031
	Total assets	$	396,634	$	619,768	$	304,669	$	77,611	$	83,701	$	17,097		$	1,499,480
	Capital expenditures	$	4,540	$	4,719	$	1,086	$	448	$	955	$	225		$	11,973
		Nine Months Ended September 30, 2013
									Granite
			Marcellus		Barnett		Fayetteville		Wash		Other			Corporate			Total
	Operating revenues	$	45,497	$	26,647	$	21,383	$	39,368	$	7,441		$	—		$	140,336
	Operating revenues—related party		162		72,856		—		1,299		—			—			74,317
	Product purchases		—		558		732		13,936		2,971			—			18,197
	Product purchases—related party		—		—		—		22,191		—			—			22,191
	Operations and maintenance
	expense		7,774		21,284		6,747		2,103		2,595			—			40,503
	General and administrative
	expense		—		—		—		—		—			28,536			28,536
	Goodwill impairment		—		—		—		—		(4,053	)		—			(4,053	)
	Gain on sale of asset		—		—		—		4,392		—			—			4,392
	Loss from unconsolidated affiliate		—		—		—		—		(447	)		—			(447	)
	EBITDA	$	37,885	$	77,661	$	13,904	$	6,829	$	(2,625	)	$	(28,536	)	$	105,118
	Goodwill	$	8,618	$	—	$	76,767	$	14,211	$	—		$	—		$	99,596
	Total assets	$	672,627	$	604,569	$	297,064	$	77,719	$	204,053		$	27,951		$	1,883,983
	Capital expenditures	$	135,845	$	8,925	$	6,818	$	6,481	$	5,954		$	573		$	164,596
		Nine Months Ended September 30, 2012
									Granite
			Marcellus		Barnett		Fayetteville		Wash		Other		Corporate			Total
	Operating revenues	$	15,003	$	12,053	$	20,368	$	28,021	$	9,791	$	—		$	85,236
	Operating revenues—related party		—		86,739		—		—		—		—			86,739
	Product purchases		—		60		343		24,514		1,838		—			26,755
	Operations and maintenance
	expense		1,328		18,438		6,399		1,619		2,269		—			30,053
	General and administrative
	expense		—		—		—		—		—		21,965			21,965
	EBITDA	$	13,675	$	80,294	$	13,626	$	1,888	$	5,684	$	(21,965	)	$	93,202
	Goodwill	$	—	$	—	$	76,767	$	14,211	$	4,053	$	—		$	95,031
	Total assets	$	396,634	$	619,768	$	304,669	$	77,611	$	83,701	$	17,097		$	1,499,480
Capital expenditures	$	5,378	$	10,718	$	10,040	$	2,411	$	5,140	$	659		$	34,346

Condensed_Consolidating_Financ1

Condensed Consolidating Financial Statements (Tables)	9 Months Ended
	Sep. 30, 2013
Condensed Consolidating Financial Statements [Abstract]	'
Schedule Of Condensed Consolidated Statements Of Income	'
		For the Three Months Ended September 30, 2013
								Guarantor		Non-Guarantor
			Issuer			Co-Issuer		Subsidiaries		Subsidiaries			Eliminations			Consolidated
		(In thousands)
	Operating revenues	$	—		$	—	$	55,457	$	15,681		$	—		$	71,138
	Operating expenses		245			—		46,077		6,348			—			52,670
	Goodwill impairment		—			—		(4,053	)	—			—			(4,053	)
	Gain on sale of asset		—			—		4,392		—			—			4,392
	Operating income (loss)		(245	)		—		9,719		9,333			—			18,807
	Loss from unconsolidated affiliate		—			—		—		(447	)		—			(447	)
	Interest and debt expense		(10,518	)		—		42		(1,149	)		—			(11,625	)
	Income (loss) before income tax		(10,763	)		—		9,761		7,737			—			6,735
	Income tax expense		—			—		347		—			—			347
	Income (loss) before earnings from
	consolidated subsidiaries		(10,763	)		—		9,414		7,737			—			6,388
	Earnings (loss) from consolidated
	subsidiaries		17,151			—		—		—			(17,151	)		—
	Net income (loss)		6,388			—		9,414		7,737			(17,151	)		6,388
	Net income attributable to noncontrolling
	interest		—			—		—		1,923			—			1,923
	Net income (loss) attributable to
	Crestwood Midstream Partners LP		6,388			—		9,414		5,814			(17,151	)		4,465
	General partner's interest in net income		81			—		—		—			—			81
	Limited partner's interest in net income
	(loss)	$	6,307		$	—	$	9,414	$	5,814		$	(17,151	)	$	4,384
		For the Three Months Ended September 30, 2012
								Guarantor			Non-Guarantor
			Issuer			Co-Issuer		Subsidiaries			Subsidiaries			Eliminations			Consolidated
		(In thousands)
	Operating revenues	$	—		$	—	$	55,037		$	7,976		$	—		$	63,013
	Operating expenses		179			—		37,009			2,233			—			39,421
	Operating income (loss)		(179	)		—		18,028			5,743			—			23,592
	Interest and debt expense		(8,147	)		—		(55	)		(703	)		—			(8,905	)
	Income (loss) before income tax		(8,326	)		—		17,973			5,040			—			14,687
	Income tax expense		—			—		306			—			—			306
	Income (loss) before earnings from
	consolidated subsidiaries		(8,326	)		—		17,667			5,040			—			14,381
	Earnings (loss) from consolidated
	subsidiaries		22,707			—		—			—			(22,707	)		—
	Net income (loss)		14,381			—		17,667			5,040			(22,707	)		14,381
	General partner's interest in net income		7,516			—		—			—			—			7,516
	Limited partner's interest in net income
	(loss)	$	6,865		$	—	$	17,667		$	5,040		$	(22,707	)	$	6,865
		For the Nine Months Ended September 30, 2013
								Guarantor			Non-Guarantor
			Issuer			Co-Issuer		Subsidiaries			Subsidiaries			Eliminations			Consolidated
		(In thousands)
	Operating revenues	$	—		$	—	$	169,389		$	45,264		$	—		$	214,653
	Operating expenses		640			—		135,891			22,514			—			159,045
	Goodwill impairment		—			—		(4,053	)		—			—			(4,053	)
	Gain on sale of asset		—			—		4,392			—			—			4,392
	Operating income (loss)		(640	)		—		33,837			22,750			—			55,947
	Loss from unconsolidated affiliate		—			—		—			(447	)		—			(447	)
	Interest and debt expense		(30,731	)		—		(91	)		(3,438	)		—			(34,260	)
	Income (loss) before income tax		(31,371	)		—		33,746			18,865			—			21,240
	Income tax expense		—			—		1,024			—			—			1,024
	Income (loss) before earnings from
	consolidated subsidiaries		(31,371	)		—		32,722			18,865			—			20,216
	Earnings (loss) from consolidated
	subsidiaries		51,587			—		—			—			(51,587	)		—
	Net income (loss)		20,216			—		32,722			18,865			(51,587	)		20,216
	Net income attributable to noncontrolling
	interest		—			—		—			1,923			—			1,923
Net income (loss) attributable to
Crestwood Midstream Partners LP		20,216			—		32,722			16,942			(51,587	)		18,293
General partner's interest in net income		10,474			—		—			—			—			10,474
Limited partner's interest in net income
(loss)	$	9,742		$	—	$	32,722		$	16,942		$	(51,587	)	$	7,819
	For the Nine Months Ended September 30, 2012
							Guarantor			Non-Guarantor
		Issuer			Co-Issuer		Subsidiaries			Subsidiaries			Eliminations			Consolidated
	(In thousands)
Operating revenues	$	—		$	—	$	156,972		$	15,003		$	—		$	171,975
Operating expenses		397			—		106,961			7,324			—			114,682
Operating income (loss)		(397	)		—		50,011			7,679			—			57,293
Interest and debt expense		(23,896	)		—		(149	)		(1,380	)		—			(25,425	)
Income (loss) before income tax		(24,293	)		—		49,862			6,299			—			31,868
Income tax expense		—			—		884			—			—			884
Income (loss) before earnings from
consolidated subsidiaries		(24,293	)		—		48,978			6,299			—			30,984
Earnings (loss) from consolidated
subsidiaries		55,277			—		—			—			(55,277	)		—
Net income (loss)		30,984			—		48,978			6,299			(55,277	)		30,984
General partner's interest in net income		15,038			—		—			—			—			15,038
Limited partner's interest in net income
(loss)	$	15,946		$	—	$	48,978		$	6,299		$	(55,277	)	$	15,946
Schedule Of Condensed Consolidated Balance Sheet	'
		As of September 30, 2013
							Guarantor	Non-Guarantor
			Issuer		Co-Issuer		Subsidiaries	Subsidiaries			Eliminations			Consolidated
		(In thousands)
	ASSETS
	Current assets
	Cash and cash equivalents	$	4,506	$	—	$	—	$	1,162	$	—		$	5,668
	Accounts receivable		1,626		—		15,024		11,016		—			27,666
	Accounts receivable—related
	party		399,755		1		23,783		12		(399,501	)		24,050
	Insurance receivable		—		—		3,072		—		—			3,072
	Prepaid expenses and other		174		—		595		22		—			791
	Total current assets		406,061		1		42,474		12,212		(399,501	)		61,247
	Investment in unconsolidated
	affiliate		—		—		—		127,651		—			127,651
	Investment in consolidated
	affiliates		1,186,766		—		—		—		(1,186,766	)		—
	Property, plant and equipment—net		3,069		—		861,728		280,075		—			1,144,872
	Intangible assets—net		—		—		112,178		316,702		—			428,880
	Goodwill		—		—		90,978		8,618		—			99,596
	Deferred financing costs, net		16,290		—		—		4,429		—			20,719
	Other assets		25		—		993		—		—			1,018
	Total assets	$	1,612,211	$	1	$	1,108,351	$	749,687	$	(1,586,267	)	$	1,883,983
	LIABILITIES AND PARTNERS'
	CAPITAL/MEMBERS' EQUITY
	Current liabilities
	Accrued additions to property,
	plant and equipment	$	—	$	—	$	24,786	$	16,462	$	—		$	41,248
	Capital leases		389		—		2,556		—		—			2,945
	Deferred revenue		—		—		—		2,426		—			2,426
	Accounts payable—related party		1,887		—		401,460		671		(399,501	)		4,517
	Accounts payable, accrued
	expenses and other
	liabilities		25,229		—		9,180		6,626		—			41,035
	Total current liabilities		27,505		—		437,982		26,185		(399,501	)		92,171
	Long-term debt		707,486		—		—		191,900		—			899,386
	Long-term capital leases		679		—		573		—		—			1,252
	Asset retirement obligations		—		—		13,759		874		—			14,633
	Partners'/members' equity		876,541		1		656,037		530,728		(1,186,766	)		876,541
	Total liabilities and
	partners'
	capital/members'
	equity	$	1,612,211	$	1	$	1,108,351	$	749,687	$	(1,586,267	)	$	1,883,983
		As of December 31, 2012
							Guarantor		Non-Guarantor
			Issuer		Co-Issuer		Subsidiaries		Subsidiaries		Eliminations			Consolidated
		(In thousands)
	ASSETS
	Current assets
	Cash and cash equivalents	$	21	$	—	$	—	$	90	$	—		$	111
	Accounts receivable		608		—		14,515		6,513		—			21,636
	Accounts receivable—related
	party		366,405		1		22,587		—		(365,238	)		23,755
	Insurance receivable		—		—		2,920		—		—			2,920
	Prepaid expenses and other		584		—		1,357		—		—			1,941
	Total current assets		367,618		1		41,379		6,603		(365,238	)		50,363
	Investment in consolidated
	affiliates		1,041,936		—		—		—		(1,041,936	)		—
	Property, plant and equipment—net		8,519		—		775,852		155,475		—			939,846
	Intangible assets—net		—		—		163,021		338,359		—			501,380
	Goodwill		—		—		95,031		—		—			95,031
	Deferred financing costs, net		17,149		—		—		5,379		—			22,528
	Other assets		20		—		1,301		—		—			1,321
Total assets	$	1,435,242	$	1	$	1,076,584	$	505,816	$	(1,407,174	)	$	1,610,469
LIABILITIES AND PARTNERS'
CAPITAL/MEMBERS' EQUITY
Current liabilities
Accrued additions to property,
plant and equipment	$	—	$	—	$	3,829	$	5,384	$	—		$	9,213
Capital leases		429		—		3,433		—		—			3,862
Deferred revenue		—		—		—		2,634		—			2,634
Accounts payable—related party		536		—		367,682		108		(365,238	)		3,088
Accounts payable, accrued
expenses and other
liabilities		15,547		—		11,876		2,294		—			29,717
Total current liabilities		16,512		—		386,820		10,420		(365,238	)		48,514
Long-term debt		558,161		—		—		127,000		—			685,161
Long-term capital leases		960		—		2,201		—		—			3,161
Asset retirement obligations		—		—		13,188		836		—			14,024
Partners'/members' equity		859,609		1		674,375		367,560		(1,041,936	)		859,609
Total liabilities and
partners'
capital/members'
equity	$	1,435,242	$	1	$	1,076,584	$	505,816	$	(1,407,174	)	$	1,610,469
Schedule Of Condensed Consolidated Statement Of Cash Flows	'
		For the Nine Months Ended September 30, 2013
								Guarantor		Non-Guarantor
			Issuer			Co-Issuer		Subsidiaries		Subsidiaries				Eliminations			Consolidated
		(In thousands)
	Net cash provided by (used in)
	operating activities	$	(18,629	)	$	—	$	102,271		$	31,506		$	(33,795	)	$	81,353
	Investing activities:
	Capital expenditures		(573	)		—		(52,464	)		(111,559	)		—			(164,596	)
	Capital contribution to
	consolidated affiliate		(82,025	)		—		—			—			82,025			—
	Proceeds from sale of asset		—			—		11,000			—			—			11,000
	Investment in unconsolidated
	affiliate		—			—		—			(128,098	)		—			(128,098	)
	Other		—			—		—			20			—			20
	Change in advances to affiliates,
	net		57,413			—		—			—			(57,413	)		—
	Net cash provided by (used in)
	investing activities		(25,185	)		—		(41,464	)		(239,637	)		24,612			(281,674	)
	Financing activities:
	Proceeds from credit facilities		343,500			—		—			139,900			—			483,400
	Repayments of credit facilities		(194,000	)		—		—			(75,000	)		—			(269,000	)
	Payments on capital leases		(321	)		—		(2,694	)		—			—			(3,015	)
	Deferred financing costs paid		(85	)		—		—			—			—			(85	)
	Proceeds from issuance of
	common units, net		118,562			—		—			—			—			118,562
	Proceeds from issuance of
	preferred equity of subsidiary		—			—		—			96,073			—			96,073
	Contributions received		—			—		—			82,025			(82,025	)		—
	Distributions to General Partner
	for additional interest in CMM		(129,000	)		—		—			—			—			(129,000	)
	Distributions paid		(90,357	)		—		—			(33,795	)		33,795			(90,357	)
	Change in advances from
	affiliates, net		—			—		(57,413	)		—			57,413			—
	Taxes paid for equity-based
	compensation vesting		—			—		(700	)		—			—			(700	)
	Net cash provided by (used in)
	financing activities		48,299			—		(60,807	)		209,203			9,183			205,878
	Change in cash and cash equivalents		4,485			—		—			1,072			—			5,557
	Cash and cash equivalents at beginning
	of period		21			—		—			90			—			111
	Cash and cash equivalents at end of
	period	$	4,506		$	—	$	—		$	1,162		$	—		$	5,668
		For the Nine Months Ended September 30, 2012
								Guarantor		Non-Guarantor
			Issuer			Co-Issuer		Subsidiaries		Subsidiaries				Eliminations			Consolidated
		(In thousands)
	Net cash provided by (used in)
	operating activities	$	(16,014	)	$	—	$	86,153		$	9,934		$	(2,205	)	$	77,868
	Investing activities:
	Acquisitions, net of cash
	acquired		—			—		(87,269	)		(381,718	)		—			(468,987	)
	Capital expenditures		(659	)		—		(28,309	)		(5,378	)		—			(34,346	)
	Acquisition of interests in
	CMM		(131,250	)		—		—			—			131,250			—
	Capital contribution to
	consolidated affiliate		1,647			—		—			—			(1,647	)		—
	Change in advances to affiliates,
	net		(31,730	)		—		—			—			31,730			—
	Net cash provided by (used in)
	investing activities		(161,992	)		—		(115,578	)		(387,096	)		161,333			(503,333	)
	Financing activities:
	Proceeds from credit facilities		350,200			—		—			27,500			—			377,700
	Repayments of credit facilities		(329,500	)		—		—			(8,000	)		—			(337,500	)
Payments on capital leases		(256	)		—		(1,899	)		—			—			(2,155	)
Deferred financing costs paid		(161	)		—		—			(6,328	)		—			(6,489	)
Proceeds from issuance of
common units, net		217,508			—		—			—			—			217,508
Contributions received		5,930			—		—			375,000			(131,250	)		249,680
Distributions paid		(66,500	)		—		—			(11,005	)		3,852			(73,653	)
Change in advances from affiliate,
net		—			—		31,730			—			(31,730	)		—
Taxes paid for equity-based
compensation vesting		—			—		(406	)		—			—			(406	)
Net cash provided by (used in)
financing activities		177,221			—		29,425			377,167			(159,128	)		424,685
Change in cash and cash equivalents		(785	)		—		—			5			—			(780	)
Cash and cash equivalents at beginning
of period		797			—		—			—			—			797
Cash and cash equivalents at end of
period	$	12		$	—	$	—		$	5		$	—		$	17

Subsequent_Event_Tables

Subsequent Event (Tables)	9 Months Ended
	Sep. 30, 2013
Subsequent Events [Abstract]	'
Pro Forma Consolidated Statements Of Operations	'
		Three Months Ended				Nine Months Ended
		September 30,				September 30,
			2013		2012		2013		2012
	Revenues	$	140	$	114	$	418	$	318
	Net income (loss)	$	12	$	24	$	40	$	63
	Net income (loss) per limited partner unit:
	Basic	$	0.02	$	0.15	$	0.17	$	0.4
	Diluted:	$	0.02	$	0.15	$	0.17	$	0.4

Organization_And_Description_O1

Organization And Description Of Business (Narrative) (Details) (USD $)	0 Months Ended
In Millions, except Share data, unless otherwise specified	Oct. 07, 2013
Number of units issued for one unit held by unitholders	1.07
Potential cash payment to unaffiliated unitholders at closing of the merger transaction	$35
Potential per share cash payment to unaffiliated unitholders at closing of the merger transaction	$1.03
Crestwood Holdings LLC [Member]	'
Potential cash payment to unaffiliated unitholders at closing of the merger transaction	10
Inergy Midstream, L.P. [Member]	'
Potential cash payment to unaffiliated unitholders at closing of the merger transaction	$25

Basis_Of_Presentation_And_Summ2

Basis Of Presentation And Summary Of Significant Accounting Policies (Details) (USD $)	0 Months Ended			3 Months Ended	9 Months Ended
	Jul. 19, 2013	Jan. 08, 2013	Mar. 26, 2012	Sep. 30, 2013	Sep. 30, 2013
					segment
Interests acquired	'	65.00%	35.00%	'	'
Payments for investment in unconsolidated affiliate	$108,000,000	'	$131,000,000	$20,000,000	$128,098,000
Payments for investment in consolidated affiliate	'	258,000,000	'	'	'
Borrowings to acquire interest in subsidiaries	'	129,000,000	'	'	'
Goodwill impairment	'	'	'	4,053,000	4,053,000
Reduction of our General Partner's capital to reflect cash paid	'	129,000,000	'	'	129,000,000
Subsidiary ownership percentage after transaction	'	100.00%	'	'	'
Reportable segments	'	'	'	'	4
Crestwood Holdings LLC [Member]	'	'	'	'	'
Interests acquired	'	'	65.00%	'	'
Payments for investment in unconsolidated affiliate	'	'	$244,000,000	'	'

Acquisitions_And_Divestitures_1

Acquisitions And Divestitures (Narrative) (Details) (USD $)

3 Months Ended

9 Months Ended

6 Months Ended

9 Months Ended

0 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2012

Jun. 30, 2013

Dec. 31, 2012

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2013

Dec. 28, 2012

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Antero Acquisition [Member]

Antero Acquisition [Member]

Devon Acquisition [Member]

EMAC Acquisition [Member]

EMAC Acquisition [Member]

Granite Wash [Member]

Granite Wash [Member]

Minimum [Member]

Maximum [Member]

CMM Credit Facility, Due March 2017 [Member]

mi

item

Antero Acquisition [Member]

Antero Acquisition [Member]

acre

Business Acquisition [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Business acquisition, cost of acquired entity, purchase price

'

'

'

'

'

'

'

$381,718,000

$87,943,000

'

$94,979,000

'

'

'

'

'

Business acquisition, purchase price allocation, property, plant and equipment

'

'

'

'

'

'

'

90,562,000

88,626,000

'

53,357,000

'

'

'

'

'

Business acquisition, reduction of depreciation, amortization and accretion expense

'

'

'

'

'

'

'

'

2,000,000

'

1,000,000

'

'

'

'

'

Business acquisition, purchase price allocation, goodwill

'

'

'

'

'

'

'

'

'

'

8,618,000

'

'

'

'

'

Purchase price paid

'

'

'

'

'

'

'

381,718,000

87,943,000

'

94,979,000

'

'

'

'

'

Gas gathering and compression agreement term

'

'

'

'

'

'

'

'20 years

'20 years

'

'

'

'

'

'

'

Area of dedication

'

'

'

'

'

'

'

127,000

'

'

'

'

'

'

'

'

Area of dedication, net

'

'

'

'

'

'

'

104,000

'

'

'

'

'

'

'

'

Minimum throughput volume delivery term

'

'

'

'

'

'

'

'7 years

'

'

'

'

'

'

'

'

Guaranteed volume commitments over seven year period, MMcfd

'

'

'

'

'

'

'

'

'

'

'

'

'

300

450

'

Receivable and deferred revenue recorded under GGA

2,426,000

'

2,426,000

'

'

2,634,000

'

'

'

'

'

'

'

'

'

'

Miles of Gathering Pipelines

'

'

'

'

'

'

'

33

'

'

'

'

'

'

'

'

Operating revenue

71,138,000

63,013,000

[1]

214,653,000

171,975,000

[1]

'

'

15,000,000

'

'

'

'

'

'

'

'

'

Operating expenses

52,670,000

39,421,000

[1]

159,045,000

114,682,000

[1]

'

'

7,000,000

'

'

'

'

'

'

'

'

'

Operating income (loss)

18,807,000

23,592,000

[1]

55,947,000

57,293,000

[1]

'

'

'

'

'

'

'

'

'

'

'

'

Credit Facility, borrowing capacity

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

200,000,000

Number of compression and dehydration stations

'

'

'

'

'

'

'

'

'

4

'

'

'

'

'

'

Compression services agreement expiration

'

'

'

'

'

'

'

'

'

'2018

'

'

'

'

'

'

Compression services agreement, optional extension term

'

'

'

'

'

'

'

'

'

'

'5 years

'

'

'

'

'

Proceeds from sale of business, net of fees

'

'

'

'

11,000,000

'

'

'

'

'

'

'

'

'

'

'

Gain on sale of asset

$4,392,000

'

$4,392,000

'

'

'

'

'

'

'

'

$4,392,000

$4,392,000

'

'

'

[1]

Financial information has been revised to include the results of Crestwood Marcellus Midstream LLC as discussed in Note 2.

Acquisitions_And_Divestitures_2

Acquisitions And Divestitures (Schedule Of Purchase Price Allocation) (Details) (USD $)	Sep. 30, 2013
In Thousands, unless otherwise specified
Antero Acquisition [Member]	'
Business Acquisition [Line Items]	'
Cash	$381,718
Total purchase price	381,718
Property, plant and equipment	90,562
Intangible assets	291,218
Total assets	381,780
Asset retirement obligation	62
Total liabilities	62
Total	381,718
EMAC Acquisition [Member]	'
Business Acquisition [Line Items]	'
Cash	94,979
Total purchase price	94,979
Property, plant and equipment	53,357
Intangible assets	33,909
Goodwill	8,618
Total assets	95,884
Asset retirement obligation	755
Environmental liability	150
Total liabilities	905
Total	94,979
Devon Acquisition [Member]	'
Business Acquisition [Line Items]	'
Cash	87,943
Total purchase price	87,943
Property, plant and equipment	88,626
Total assets	88,626
Asset retirement obligation	483
Environmental liability	200
Total liabilities	683
Total	$87,943

Earnings_Per_Limited_Partner_U2

Earnings Per Limited Partner Unit And Distributions (Narrative) (Details) (USD $)

0 Months Ended

3 Months Ended

9 Months Ended

0 Months Ended

3 Months Ended

9 Months Ended

0 Months Ended

3 Months Ended

9 Months Ended

In Millions, except Share data, unless otherwise specified

Oct. 07, 2013

Apr. 05, 2013

Mar. 22, 2013

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2012

Jan. 08, 2013

Sep. 30, 2012

Jun. 30, 2012

Mar. 31, 2012

Sep. 30, 2013

Jan. 08, 2013

Jun. 30, 2013

Mar. 31, 2013

Sep. 30, 2013

General Partner [Member]

Class C Unitholders [Member]

Class C Unitholders [Member]

Class C Unitholders [Member]

Class C Unitholders [Member]

Class D Unitholder [Member]

Class D Unitholder [Member]

Class D Unitholder [Member]

Class D Unitholder [Member]

Distribution period

'

'

'

'

'

'45 days

'

'

'

'

'

'

'

'

'

'

Distribution weighted average common unit price period

'

'

'

'

'

'

'

'

'

'

'

'10 days

'

'

'

'10 days

Number of units issued for one unit held by unitholders

1.07

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

General partners, additional units issued

'

'

'

'

'

'

'

133,060

174,230

138,731

136,128

'

6,190,469

141,422

151,238

'

Units excluded from our dilutive earnings per share

'

'

'

3,262,275

0

1,099,375

0

'

'

'

'

'

'

'

'

'

Public offering of common units

'

675,000

4,500,000

'

'

'

'

'

'

'

'

'

'

'

'

'

Public offering of common units, per share amount

'

'

$23.90

'

'

'

'

'

'

'

'

'

'

'

'

'

Public offering of common units, per share amount net of underwriting discount

'

'

$23

'

'

'

'

'

'

'

'

'

'

'

'

'

Net proceeds from public offering

'

$15.50

$103.50

'

'

'

'

'

'

'

'

'

'

'

'

'

Period for which the underwriter had the option to purchase shares

'

'

'

'

'

'30 days

'

'

'

'

'

'

'

'

'

'

Earnings_Per_Limited_Partner_U3

Earnings Per Limited Partner Unit And Distributions (Allocation Of Net Income To General Partner And Limited Partners) (Details) (USD $)	3 Months Ended				9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013		Sep. 30, 2012		Sep. 30, 2013		Sep. 30, 2012
Earnings Per Limited Partner Unit And Distributions [Abstract]	'		'		'		'
Net income attributable to CMLP	$4,465		$14,381	[1]	$18,293		$30,984	[1]
General Partner's incentive distributions	'	[2]	-4,101	[2]	-10,140	[2]	-10,636	[2]
Net income attributable to CMLP after incentive distributions	4,465		10,280		8,153		20,348
General Partner's interest in net income attributable to CMLP after incentive distributions	-81		-3,415		-334		-4,402
Limited Partners' interest in net income attributable to CMLP after distributions	$4,384		$6,865	[1]	$7,819		$15,946	[1]
[1]	Financial information has been revised to include the results of Crestwood Marcellus Midstream LLC as discussed in Note 2.
[2]	As a result of the Merger on October 7, 2013 described in Note 1. Organization and Description of Business, there were no distributions to CMLP's unitholders for the three months ended September 30, 2013; therefore, our General Partner did not receive any incentive distributions attributable to that period.

Earnings_Per_Limited_Partner_U4

Earnings Per Limited Partner Unit And Distributions (Schedule Of Reconciliation Of Earnings Per Share) (Details) (USD $)	3 Months Ended				9 Months Ended
In Thousands, except Share data, unless otherwise specified	Sep. 30, 2013		Sep. 30, 2012		Sep. 30, 2013		Sep. 30, 2012
Limited partners' interest in net income attributable to Crestwood Midstream Partners LP	$4,384		$6,865	[1]	$7,819		$15,946	[1]
Weighted-average limited partner units - basic	60,188,000	[2]	46,564,000	[2]	58,339,000	[3]	44,206,000	[3]
Effect of unvested dilutive units	260,000		203,000		269,000		189,000
Weighted-average limited partner units - diluted	60,448,000	[2]	46,767,000	[2]	58,608,000	[3]	44,395,000	[3]
Basic and diluted net income attributable to CMLP per limited partner unit	$0.07		$0.15	[1]	$0.13		$0.36	[1]
Class D Unitholder [Member]	'		'		'		'
Weighted-average limited partner units - basic	6,421,641		'		'		'
Common Class C And Class D [Member]	'		'		'		'
Weighted-average limited partner units - basic	'		'		8,536,178		'
Class C Unitholders [Member]	'		'		'		'
Weighted-average limited partner units - basic	'		6,929,763		'		6,795,130
[1]	Financial information has been revised to include the results of Crestwood Marcellus Midstream LLC as discussed in Note 2.
[2]	The three months ended September 30, 2013 includes 6,421,641 Class D units. The three months ended September 30, 2012 includes 6,929,763 Class C units.
[3]	The nine months ended September 30, 2013 includes 8,536,178 Class C and Class D units. The nine months ended September 30, 2012 includes 6,795,130 Class C units.

Earnings_Per_Limited_Partner_U5

Earnings Per Limited Partner Unit And Distributions (Schedule Of Distributions Made To Partners) (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Jun. 30, 2012	Sep. 30, 2013		Sep. 30, 2012
Partners' Capital and Distributions [Line Items]	'	'	'		'
Total Cash	'	'	$90,357,000		$73,653,000	[1]
Cash distributions excluded	4,000,000	3,000,000	'		'
August 9, 2013 [Member]	'	'	'		'
Partners' Capital and Distributions [Line Items]	'	'	'		'
Attributable to the Quarter Ended	'	'	30-Jun-13		'
Per Unit Distribution, Paid	'	'	$0.51		'
Total Cash	'	'	32,600,000		'
Total Distribution	'	'	36,300,000		'
May 10, 2013 [Member]	'	'	'		'
Partners' Capital and Distributions [Line Items]	'	'	'		'
Attributable to the Quarter Ended	'	'	31-Mar-13		'
Per Unit Distribution, Paid	'	'	$0.51		'
Total Cash	'	'	32,600,000		'
Total Distribution	'	'	36,300,000		'
February 12, 2013 [Member]	'	'	'		'
Partners' Capital and Distributions [Line Items]	'	'	'		'
Attributable to the Quarter Ended	'	'	31-Dec-12		'
Per Unit Distribution, Paid	'	'	$0.51		'
Total Cash	'	'	25,100,000		'
Total Distribution	'	'	29,400,000		'
November 9, 2012 [Member]	'	'	'		'
Partners' Capital and Distributions [Line Items]	'	'	'		'
Attributable to the Quarter Ended	'	'	30-Sep-12		'
Per Unit Distribution, Paid	'	'	$0.51		'
Total Cash	'	'	25,100,000		'
Total Distribution	'	'	29,200,000		'
August 10, 2012 [Member]	'	'	'		'
Partners' Capital and Distributions [Line Items]	'	'	'		'
Attributable to the Quarter Ended	'	'	30-Jun-12		'
Per Unit Distribution, Paid	'	'	$0.50		'
Total Cash	'	'	24,300,000		'
Total Distribution	'	'	28,200,000		'
May11, 2012 [Member]	'	'	'		'
Partners' Capital and Distributions [Line Items]	'	'	'		'
Attributable to the Quarter Ended	'	'	31-Mar-12		'
Per Unit Distribution, Paid	'	'	$0.50		'
Total Cash	'	'	21,500,000		'
Total Distribution	'	'	25,400,000		'
February 10, 2012 [Member].	'	'	'		'
Partners' Capital and Distributions [Line Items]	'	'	'		'
Attributable to the Quarter Ended	'	'	31-Dec-11		'
Per Unit Distribution, Paid	'	'	$0.49		'
Total Cash	'	'	20,700,000		'
Total Distribution	'	'	24,400,000		'
Limited Partner [Member] | August 9, 2013 [Member]	'	'	'		'
Partners' Capital and Distributions [Line Items]	'	'	'		'
Total Cash Distribution, Paid	'	'	27,400,000	[2]	'
Limited Partner [Member] | May 10, 2013 [Member]	'	'	'		'
Partners' Capital and Distributions [Line Items]	'	'	'		'
Total Cash Distribution, Paid	'	'	27,400,000	[2]	'
Limited Partner [Member] | February 12, 2013 [Member]	'	'	'		'
Partners' Capital and Distributions [Line Items]	'	'	'		'
Total Cash Distribution, Paid	'	'	21,000,000	[2]	'
Limited Partner [Member] | November 9, 2012 [Member]	'	'	'		'
Partners' Capital and Distributions [Line Items]	'	'	'		'
Total Cash Distribution, Paid	'	'	21,000,000	[2]	'
Limited Partner [Member] | August 10, 2012 [Member]	'	'	'		'
Partners' Capital and Distributions [Line Items]	'	'	'		'
Total Cash Distribution, Paid	'	'	20,600,000	[2]	'
Limited Partner [Member] | May11, 2012 [Member]	'	'	'		'
Partners' Capital and Distributions [Line Items]	'	'	'		'
Total Cash Distribution, Paid	'	'	18,200,000	[2]	'
Limited Partner [Member] | February 10, 2012 [Member].	'	'	'		'
Partners' Capital and Distributions [Line Items]	'	'	'		'
Total Cash Distribution, Paid	'	'	17,900,000	[2]	'
General Partner [Member] | August 9, 2013 [Member]	'	'	'		'
Partners' Capital and Distributions [Line Items]	'	'	'		'
Total Cash Distribution, Paid	'	'	5,200,000		'
General Partner [Member] | May 10, 2013 [Member]	'	'	'		'
Partners' Capital and Distributions [Line Items]	'	'	'		'
Total Cash Distribution, Paid	'	'	5,200,000		'
General Partner [Member] | February 12, 2013 [Member]	'	'	'		'
Partners' Capital and Distributions [Line Items]	'	'	'		'
Total Cash Distribution, Paid	'	'	4,100,000		'
General Partner [Member] | November 9, 2012 [Member]	'	'	'		'
Partners' Capital and Distributions [Line Items]	'	'	'		'
Total Cash Distribution, Paid	'	'	4,100,000		'
General Partner [Member] | August 10, 2012 [Member]	'	'	'		'
Partners' Capital and Distributions [Line Items]	'	'	'		'
Total Cash Distribution, Paid	'	'	3,700,000		'
General Partner [Member] | May11, 2012 [Member]	'	'	'		'
Partners' Capital and Distributions [Line Items]	'	'	'		'
Total Cash Distribution, Paid	'	'	3,300,000		'
General Partner [Member] | February 10, 2012 [Member].	'	'	'		'
Partners' Capital and Distributions [Line Items]	'	'	'		'
Total Cash Distribution, Paid	'	'	2,800,000		'
Class C Unitholders [Member] | Limited Partner [Member] | February 12, 2013 [Member]	'	'	'		'
Partners' Capital and Distributions [Line Items]	'	'	'		'
PIK Value to unitholders	'	'	3,700,000		'
Class C Unitholders [Member] | Limited Partner [Member] | November 9, 2012 [Member]	'	'	'		'
Partners' Capital and Distributions [Line Items]	'	'	'		'
PIK Value to unitholders	'	'	3,500,000		'
Class C Unitholders [Member] | Limited Partner [Member] | August 10, 2012 [Member]	'	'	'		'
Partners' Capital and Distributions [Line Items]	'	'	'		'
PIK Value to unitholders	'	'	3,400,000		'
Class C Unitholders [Member] | Limited Partner [Member] | May11, 2012 [Member]	'	'	'		'
Partners' Capital and Distributions [Line Items]	'	'	'		'
PIK Value to unitholders	'	'	3,400,000		'
Class C Unitholders [Member] | Limited Partner [Member] | February 10, 2012 [Member].	'	'	'		'
Partners' Capital and Distributions [Line Items]	'	'	'		'
PIK Value to unitholders	'	'	3,200,000		'
Class C Unitholders [Member] | General Partner [Member] | February 12, 2013 [Member]	'	'	'		'
Partners' Capital and Distributions [Line Items]	'	'	'		'
PIK Value to unitholders	'	'	600,000		'
Class C Unitholders [Member] | General Partner [Member] | November 9, 2012 [Member]	'	'	'		'
Partners' Capital and Distributions [Line Items]	'	'	'		'
PIK Value to unitholders	'	'	600,000		'
Class C Unitholders [Member] | General Partner [Member] | August 10, 2012 [Member]	'	'	'		'
Partners' Capital and Distributions [Line Items]	'	'	'		'
PIK Value to unitholders	'	'	500,000		'
Class C Unitholders [Member] | General Partner [Member] | May11, 2012 [Member]	'	'	'		'
Partners' Capital and Distributions [Line Items]	'	'	'		'
PIK Value to unitholders	'	'	500,000		'
Class C Unitholders [Member] | General Partner [Member] | February 10, 2012 [Member].	'	'	'		'
Partners' Capital and Distributions [Line Items]	'	'	'		'
PIK Value to unitholders	'	'	500,000		'
Class D Unitholder [Member] | Limited Partner [Member] | August 9, 2013 [Member]	'	'	'		'
Partners' Capital and Distributions [Line Items]	'	'	'		'
PIK Value to unitholders	'	'	3,200,000		'
Class D Unitholder [Member] | Limited Partner [Member] | May 10, 2013 [Member]	'	'	'		'
Partners' Capital and Distributions [Line Items]	'	'	'		'
PIK Value to unitholders	'	'	3,200,000		'
Class D Unitholder [Member] | General Partner [Member] | August 9, 2013 [Member]	'	'	'		'
Partners' Capital and Distributions [Line Items]	'	'	'		'
PIK Value to unitholders	'	'	500,000		'
Class D Unitholder [Member] | General Partner [Member] | May 10, 2013 [Member]	'	'	'		'
Partners' Capital and Distributions [Line Items]	'	'	'		'
PIK Value to unitholders	'	'	$500,000		'
[1]	Financial information has been revised to include the results of Crestwood Marcellus Midstream LLC as discussed in Note 2.
[2]	Distributions for the quarters ended June 30, 2012 and September 30, 2012 exclude approximately $3 million and $4 million paid by CMM to Crestwood Holdings.

Investment_In_Unconsolidated_A1

Investment In Unconsolidated Affiliate (Details) (USD $)	0 Months Ended		3 Months Ended	9 Months Ended			9 Months Ended
	Jul. 19, 2013	Mar. 26, 2012	Sep. 30, 2013	Sep. 30, 2013	Sep. 30, 2013	Sep. 30, 2013	Sep. 30, 2012
					Jackalope Gas Gathering Services, L.L.C. [Member]	Access Midstream Partners, L.P. [Member]	Issuer [Member]
					mi
					hp
					acre
Ownership percentage	'	'	50.00%	50.00%	'	50.00%	'
Miles of Gathering Pipelines	'	'	'	'	100	'	'
Horsepower of Equipment	'	'	'	'	9,400	'	'
Gas Gathering and Compression Agreement Term	'	'	'	'	'20 years	'	'
Area of dedication, gross	'	'	'	'	311,000	'	'
Payments for investment in unconsolidated affiliate	$108,000,000	$131,000,000	$20,000,000	$128,098,000	'	'	$131,250,000
The company's share of net income	'	'	'	200,000	'	'	'
Balance exceeding the net equity in the underlying net assets	'	'	57,000,000	57,000,000	'	'	'
Reduction of earnings from unconsolidated affiliate	'	'	$600,000	$600,000	'	'	'

Preferred_Equity_Of_Subsidiary1

Preferred Equity Of Subsidiary (Details) (USD $)	3 Months Ended	9 Months Ended	3 Months Ended	9 Months Ended	0 Months Ended
	Sep. 30, 2013	Sep. 30, 2013	Sep. 30, 2013	Sep. 30, 2013	Oct. 30, 2013
			Crestwood Niobrara [Member]	Crestwood Niobrara [Member]	Subsequent Event [Member]
Percentage of funds from future capital contributions	'	'	'	75.00%	'
Maximum amount of funds from future capital contributions	'	'	'	$69,000,000	'
Proceeds from issuance of preferred equity of subsidiary, net	'	96,073,000	81,000,000	81,000,000	'
Proceeds from additional capital contributions	'	'	15,000,000	15,000,000	'
Net income attributable to noncontrolling interest	$1,923,000	$1,923,000	'	'	'
Shares issued in lieu of cash	'	'	'	'	2,161,657

Financial_Instruments_Narrativ

Financial Instruments (Narrative) (Details) (USD $)

12 Months Ended

3 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

9 Months Ended

12 Months Ended

Dec. 31, 2010

Jan. 08, 2013

Mar. 26, 2012

Sep. 30, 2013

Sep. 30, 2013

Dec. 31, 2012

Sep. 30, 2013

Sep. 30, 2013

Dec. 31, 2012

Sep. 30, 2013

Dec. 31, 2012

Apr. 30, 2011

CMM Credit Facility, Due March 2017 [Member]

CMM Credit Facility, Due March 2017 [Member]

CMM Credit Facility, Due March 2017 [Member]

CMLP Credit Facility, Due November 2017 [Member]

CMLP Credit Facility, Due November 2017 [Member]

CMLP Credit Facility, Due November 2017 [Member]

Senior Notes, Due 2019 [Member]

Senior Notes, Due 2019 [Member]

Senior Notes, Due 2019 [Member]

Debt Instrument [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

Credit Facility, borrowing capacity

'

'

'

$200,000,000

$200,000,000

'

$550,000,000

$550,000,000

'

'

'

'

Credit Facility, outstanding

'

'

'

191,900,000

191,900,000

127,000,000

356,200,000

356,200,000

206,700,000

'

'

'

Credit Facility, average outstanding borrowings

'

'

'

157,000,000

126,000,000

'

343,000,000

330,000,000

'

'

'

'

Credit Facility, maximum outstanding borrowings

'

'

'

192,000,000

192,000,000

'

365,000,000

373,000,000

'

'

'

'

Credit Agreement LIBOR Interest Rate Margin

'

'

'

2.80%

2.80%

2.50%

2.80%

2.80%

2.50%

'

'

'

Weighted-average interest rate

'

'

'

3.00%

3.00%

2.80%

3.00%

3.00%

2.80%

'

'

'

Debt instrument, face amount

'

'

'

'

'

'

'

'

'

$150,000,000

'

$200,000,000

Debt instrument, interest rate

'

'

'

'

'

'

'

'

'

7.75%

7.75%

'

Debt instrument, maturity date

'

'

'

'

'

'

'

'

'

1-Apr-19

1-Apr-19

'

Conversion average common unit price period

'20 days

'

'

'

'

'

'

'

'

'

'

'

Interests acquired

'

65.00%

35.00%

'

'

'

'

'

'

'

'

'

Financial_Instruments_Schedule

Financial Instruments (Schedule Of Carrying Values And Estimated Fair Values Of Senior Notes) (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Financial Instruments [Abstract]	'	'
Senior Notes, Carrying Amount	$351	$351
Senior Notes, Fair Value	$369	$365

Financial_Instruments_Schedule1

Financial Instruments (Schedule Of Debt) (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Debt Instrument [Line Items]	'	'
Senior Notes, due April 2019	$350,000	$350,000
Long-term debt, gross	898,100	683,700
Plus: Unamortized premium on Senior Notes	1,286	1,461
Total long-term debt	899,386	685,161
CMM Credit Facility, Due March 2017 [Member]	'	'
Debt Instrument [Line Items]	'	'
Credit facility used for acquisition	191,900	127,000
CMLP Credit Facility, Due November 2017 [Member]	'	'
Debt Instrument [Line Items]	'	'
Credit facility used for acquisition	$356,200	$206,700

Accounts_Payable_Accrued_Expen2

Accounts Payable, Accrued Expenses And Other Liabilities (Schedule Of Accounts Payable And Other Liabilities) (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Accounts Payable, Accrued Expenses And Other Liabilities [Abstract]	'	'
Accrued expenses	$11,305	$9,608
Accrued property taxes	5,843	5,638
Accrued product purchases payable	1,818	2,450
Tax payable	1,353	2,159
Interest payable	14,054	7,505
Accounts payable	6,653	2,278
Other	9	79
Total accounts payable, accrued expenses and other liabilities	$41,035	$29,717

Commitments_And_Contingent_Lia1

Commitments And Contingent Liabilities (Narrative) (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Accrual for legal matters	$0.40	'
Accrual for environmental matters	0.3	0.2
Potential liability related to environmental exposures minimum	0.3	'
Potential liability related to environmental exposures maximum	0.5	'
Maximum [Member]	'	'
Accrual for legal matters	'	$0.10

Income_Taxes_Details

Income Taxes (Details)	9 Months Ended
	Sep. 30, 2013
Income Taxes [Abstract]	'
Texas margin tax rate	0.70%

Equity_Plan_Narrative_Details

Equity Plan (Narrative) (Details) (USD $)	9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012		Sep. 30, 2013	Dec. 31, 2012
				Phantom And Restricted Units [Member]	Phantom And Restricted Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'		'	'
Unvested compensation cost	'	'		$4,000,000	$3,000,000
Compensation expense	2,138,000	1,528,000	[1]	'	'
Grants of units, estimated grant date fair value	'	'		$5,000,000	'
Common units to satisfy employee tax withholding obligations	3,341	414		'	'
[1]	Financial information has been revised to include the results of Crestwood Marcellus Midstream LLC as discussed in Note 2.

Equity_Plan_Schedule_Of_Phanto

Equity Plan (Schedule Of Phantom And Restricted Unit Activity) (Details) (2007 Equity Plan [Member], USD $)	9 Months Ended
	Sep. 30, 2013	Sep. 30, 2013	Sep. 30, 2013	Sep. 30, 2013	Dec. 31, 2012	Sep. 30, 2013	Dec. 31, 2012
	Phantom Units [Member]	Phantom Units [Member]	Restricted Units [Member]	Phantom And Restricted Units [Member]	Phantom And Restricted Units [Member]	Phantom And Restricted Units [Member]	Phantom And Restricted Units [Member]
	Payable In Cash [Member]	Payable In Units [Member]	Payable In Units [Member]	Payable In Cash [Member]	Payable In Cash [Member]	Payable In Units [Member]	Payable In Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'	'	'	'
Unvested units - January 1	'	'	'	$26.02	$26.45	$26.01	$28.35
Unvested units - January 1, units	'	'	'	4,945	8,312	322,230	221,992
Vested	$27.22	$28.70	$26.40	'	'	'	'
Vested, units	-3,013	-71,006	-11,349	'	'	'	'
Granted	'	$24.33	$24.86	'	'	'	'
Granted, units	'	161,807	27,900	'	'	'	'
Cancelled	$25.81	$27.96	'	'	'	'	'
Cancelled, units	-354	-7,114	'	'	'	'	'
Unvested units - September 30	'	'	'	$26.02	$26.45	$26.01	$28.35
Unvested units - September 30, units	'	'	'	4,945	8,312	322,230	221,992

Transactions_With_Related_Part2

Transactions With Related Parties (Narrative) (Details) (USD $)	3 Months Ended	9 Months Ended	3 Months Ended	9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2012
			Maximum [Member]	Maximum [Member]
Related Party Transaction [Line Items]	'	'	'	'
Reimbursements of operating expenses	$1	$2	$1	$1

Transactions_With_Related_Part3

Transactions With Related Parties (Schedule Of Revenues, Expenses And Reimbursements From Affiliates) (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Transactions With Related Parties [Abstract]	'	'	'	'
Operating revenues	$24,147,000	$27,956,000	$74,317,000	$86,739,000
Operating expenses	$13,000,000	$5,000,000	$39,000,000	$15,000,000

Segment_Information_Narrative_

Segment Information (Narrative) (Details)	9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012
Revenue, Major Customer [Line Items]	'	'
Operating segments	8	'
Reportable segments	4	'
Barnett Shale [Member]	'	'
Revenue, Major Customer [Line Items]	'	'
Revenue percentages, significant customer concentration	34.00%	50.00%
Marcellus [Member]	'	'
Revenue, Major Customer [Line Items]	'	'
Revenue percentages, significant customer concentration	21.00%	'
Fayetteville Shale [Member]	'	'
Revenue, Major Customer [Line Items]	'	'
Revenue percentages, significant customer concentration	'	10.00%
Granite Wash [Member]	'	'
Revenue, Major Customer [Line Items]	'	'
Revenue percentages, significant customer concentration	10.00%	'

Segment_Information_Reconcilia

Segment Information (Reconciliation Of Net Income To EBITDA) (Details) (USD $)	3 Months Ended			9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012		Sep. 30, 2013	Sep. 30, 2012
Segment Information [Abstract]	'	'		'	'
Net income	$6,388	$14,381	[1]	$20,216	$30,984	[1]
Interest and debt expense	11,625	8,905	[1]	34,260	25,425	[1]
Income tax expense	347	306	[1]	1,024	884	[1]
Depreciation, amortization and accretion expense	14,557	11,568	[1]	49,618	35,909	[1]
EBITDA	$32,917	$35,160		$105,118	$93,202
[1]	Financial information has been revised to include the results of Crestwood Marcellus Midstream LLC as discussed in Note 2.

Segment_Information_Schedule_O

Segment Information (Schedule Of Reportable Segment Data) (Details) (USD $)	3 Months Ended			9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012		Sep. 30, 2013	Sep. 30, 2012		Dec. 31, 2012
Segment Reporting Information [Line Items]	'	'		'	'		'
Operating revenues	$46,991	$35,057		$140,336	$85,236		'
Operating revenues - related party	24,147	27,956		74,317	86,739		'
Product purchases	5,295	10,341	[1]	18,197	26,755	[1]	'
Product purchases - related party	7,556	'		22,191	'		'
Operations and maintenance expense	14,895	10,942	[1]	40,503	30,053	[1]	'
General and administrative expense	10,367	6,570	[1]	28,536	21,965	[1]	'
Goodwill impairment	-4,053	'		-4,053	'		'
Gain on sale of asset	4,392	'		4,392	'		'
Loss from unconsolidated affiliate	-447	'		-447	'		'
EBITDA	32,917	35,160		105,118	93,202		'
Goodwill	99,596	95,031		99,596	95,031		95,031
Total assets	1,883,983	1,499,480		1,883,983	1,499,480		1,610,469
Capital expenditures	84,299	11,973		164,596	34,346	[1]	'
Marcellus [Member]	'	'		'	'		'
Segment Reporting Information [Line Items]	'	'		'	'		'
Operating revenues	15,914	7,976		45,497	15,003		'
Operating revenues - related party	74	'		162	'		'
Operations and maintenance expense	2,832	815		7,774	1,328		'
EBITDA	13,156	7,161		37,885	13,675		'
Goodwill	8,618	'		8,618	'		'
Total assets	672,627	396,634		672,627	396,634		'
Capital expenditures	71,124	4,540		135,845	5,378		'
Barnett Shale [Member]	'	'		'	'		'
Segment Reporting Information [Line Items]	'	'		'	'		'
Operating revenues	8,257	5,390		26,647	12,053		'
Operating revenues - related party	23,624	27,956		72,856	86,739		'
Product purchases	157	60		558	60		'
Operations and maintenance expense	7,717	6,963		21,284	18,438		'
EBITDA	24,007	26,323		77,661	80,294		'
Total assets	604,569	619,768		604,569	619,768		'
Capital expenditures	156	4,719		8,925	10,718		'
Fayetteville Shale [Member]	'	'		'	'		'
Segment Reporting Information [Line Items]	'	'		'	'		'
Operating revenues	7,799	7,174		21,383	20,368		'
Product purchases	249	137		732	343		'
Operations and maintenance expense	2,303	1,855		6,747	6,399		'
EBITDA	5,247	5,182		13,904	13,626		'
Goodwill	76,767	76,767		76,767	76,767		'
Total assets	297,064	304,669		297,064	304,669		'
Capital expenditures	4,106	1,086		6,818	10,040		'
Granite Wash [Member]	'	'		'	'		'
Segment Reporting Information [Line Items]	'	'		'	'		'
Operating revenues	12,733	10,702		39,368	28,021		'
Operating revenues - related party	449	'		1,299	'		'
Product purchases	3,872	9,481		13,936	24,514		'
Product purchases - related party	7,556	'		22,191	'		'
Operations and maintenance expense	810	560		2,103	1,619		'
Gain on sale of asset	4,392	'		4,392	'		'
EBITDA	5,336	661		6,829	1,888		'
Goodwill	14,211	14,211		14,211	14,211		'
Total assets	77,719	77,611		77,719	77,611		'
Capital expenditures	3,958	448		6,481	2,411		'
Other [Member]	'	'		'	'		'
Segment Reporting Information [Line Items]	'	'		'	'		'
Operating revenues	2,288	3,815		7,441	9,791		'
Product purchases	1,017	663		2,971	1,838		'
Operations and maintenance expense	1,233	749		2,595	2,269		'
Goodwill impairment	-4,053	'		-4,053	'		'
Loss from unconsolidated affiliate	-447	'		-447	'		'
EBITDA	-4,462	2,403		-2,625	5,684		'
Goodwill	'	4,053		'	4,053		'
Total assets	204,053	83,701		204,053	83,701		'
Capital expenditures	4,794	955		5,954	5,140		'
Corporate [Member]	'	'		'	'		'
Segment Reporting Information [Line Items]	'	'		'	'		'
General and administrative expense	10,367	6,570		28,536	21,965		'
EBITDA	-10,367	-6,570		-28,536	-21,965		'
Total assets	27,951	17,097		27,951	17,097		'
Capital expenditures	$161	$225		$573	$659		'
[1]	Financial information has been revised to include the results of Crestwood Marcellus Midstream LLC as discussed in Note 2.

Condensed_Consolidating_Financ2

Condensed Consolidating Financial Statements (Narrative) (Details) (Senior Notes, Due 2019 [Member])	9 Months Ended	12 Months Ended
	Sep. 30, 2013	Dec. 31, 2012
Senior Notes, Due 2019 [Member]	'	'
Debt instrument, interest rate	7.75%	7.75%
Debt instrument, maturity date	1-Apr-19	1-Apr-19

Condensed_Consolidating_Financ3

Condensed Consolidating Financial Statements (Schedule Of Condensed Consolidated Statements Of Income) (Details) (USD $)	3 Months Ended			9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012		Sep. 30, 2013	Sep. 30, 2012
Operating revenues	$71,138	$63,013	[1]	$214,653	$171,975	[1]
Operating expenses	52,670	39,421	[1]	159,045	114,682	[1]
Goodwill impairment	-4,053	'		-4,053	'
Gain on sale of asset	4,392	'		4,392	'
Operating income (loss)	18,807	23,592	[1]	55,947	57,293	[1]
Loss from unconsolidated affiliate	-447	'		-447	'
Interest and debt expense	-11,625	-8,905	[1]	-34,260	-25,425	[1]
Income (loss) before income tax	6,735	14,687	[1]	21,240	31,868	[1]
Income tax expense	347	306	[1]	1,024	884	[1]
Income before earnings from consolidated subsidiaries	6,388	14,381		20,216	30,984
Net income	6,388	14,381	[1]	20,216	30,984	[1]
Net income attributable to noncontrolling interest	1,923	'		1,923	'
Net income attributable to Crestwood Midstream Partners LP	4,465	14,381	[1]	18,293	30,984	[1]
General partner's interest in net income	81	7,516	[1]	10,474	15,038	[1]
Limited partner's interest in net income (loss)	4,384	6,865	[1]	7,819	15,946	[1]
Issuer [Member]	'	'		'	'
Operating expenses	245	179		640	397
Operating income (loss)	-245	-179		-640	-397
Interest and debt expense	-10,518	-8,147		-30,731	-23,896
Income (loss) before income tax	-10,763	-8,326		-31,371	-24,293
Income before earnings from consolidated subsidiaries	-10,763	-8,326		-31,371	-24,293
Earnings (loss) from consolidated subsidiaries	17,151	22,707		51,587	55,277
Net income	6,388	14,381		20,216	30,984
Net income attributable to Crestwood Midstream Partners LP	6,388	'		20,216	'
General partner's interest in net income	81	7,516		10,474	15,038
Limited partner's interest in net income (loss)	6,307	6,865		9,742	15,946
Guarantor Subsidiaries [Member]	'	'		'	'
Operating revenues	55,457	55,037		169,389	156,972
Operating expenses	46,077	37,009		135,891	106,961
Goodwill impairment	-4,053	'		-4,053	'
Gain on sale of asset	4,392	'		4,392	'
Operating income (loss)	9,719	18,028		33,837	50,011
Interest and debt expense	42	-55		-91	-149
Income (loss) before income tax	9,761	17,973		33,746	49,862
Income tax expense	347	306		1,024	884
Income before earnings from consolidated subsidiaries	9,414	17,667		32,722	48,978
Net income	9,414	17,667		32,722	48,978
Net income attributable to Crestwood Midstream Partners LP	9,414	'		32,722	'
Limited partner's interest in net income (loss)	9,414	17,667		32,722	48,978
Non-Guarantor Subsidiaries [Member]	'	'		'	'
Operating revenues	15,681	7,976		45,264	15,003
Operating expenses	6,348	2,233		22,514	7,324
Operating income (loss)	9,333	5,743		22,750	7,679
Loss from unconsolidated affiliate	-447	'		-447	'
Interest and debt expense	-1,149	-703		-3,438	-1,380
Income (loss) before income tax	7,737	5,040		18,865	6,299
Income before earnings from consolidated subsidiaries	7,737	5,040		18,865	6,299
Net income	7,737	5,040		18,865	6,299
Net income attributable to noncontrolling interest	1,923	'		1,923	'
Net income attributable to Crestwood Midstream Partners LP	5,814	'		16,942	'
Limited partner's interest in net income (loss)	5,814	5,040		16,942	6,299
Eliminations [Member]	'	'		'	'
Earnings (loss) from consolidated subsidiaries	-17,151	-22,707		-51,587	-55,277
Net income	-17,151	-22,707		-51,587	-55,277
Net income attributable to Crestwood Midstream Partners LP	-17,151	'		-51,587	'
Limited partner's interest in net income (loss)	($17,151)	($22,707)		($51,587)	($55,277)
[1]	Financial information has been revised to include the results of Crestwood Marcellus Midstream LLC as discussed in Note 2.

Condensed_Consolidating_Financ4

Condensed Consolidating Financial Statements (Schedule Of Condensed Consolidated Balance Sheet) (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012	Sep. 30, 2012		Dec. 31, 2011
In Thousands, unless otherwise specified
Cash and cash equivalents	$5,668	$111	$17	[1]	$797	[1]
Accounts receivable	27,666	21,636	'		'
Accounts receivable - related party	24,050	23,755	'		'
Insurance receivable	3,072	2,920	'		'
Prepaid expenses and other	791	1,941	'		'
Total current assets	61,247	50,363	'		'
Investment in unconsolidated affiliate	127,651	'	'		'
Properties, plant and equipment, net	1,144,872	939,846	'		'
Intangible assets, net	428,880	501,380	'		'
Goodwill	99,596	95,031	95,031		'
Deferred financing costs, net	20,719	22,528	'		'
Other assets	1,018	1,321	'		'
Total assets	1,883,983	1,610,469	1,499,480		'
Accrued additions to property, plant and equipment	41,248	9,213	'		'
Capital leases	2,945	3,862	'		'
Deferred revenue	2,426	2,634	'		'
Accounts payable - related party	4,517	3,088	'		'
Accounts payable, accrued expenses and other liabilities	41,035	29,717	'		'
Total current liabilities	92,171	48,514	'		'
Long-term debt	899,386	685,161	'		'
Long-term capital leases	1,252	3,161	'		'
Asset retirement obligations	14,633	14,024	'		'
Partners'/members' equity	876,541	859,609	881,264	[1]	455,623
Total liabilities and partners' capital	1,883,983	1,610,469	'		'
Issuer [Member]	'	'	'		'
Cash and cash equivalents	4,506	21	12		797
Accounts receivable	1,626	608	'		'
Accounts receivable - related party	399,755	366,405	'		'
Prepaid expenses and other	174	584	'		'
Total current assets	406,061	367,618	'		'
Investment in consolidated affiliates	1,186,766	1,041,936	'		'
Properties, plant and equipment, net	3,069	8,519	'		'
Deferred financing costs, net	16,290	17,149	'		'
Other assets	25	20	'		'
Total assets	1,612,211	1,435,242	'		'
Capital leases	389	429	'		'
Accounts payable - related party	1,887	536	'		'
Accounts payable, accrued expenses and other liabilities	25,229	15,547	'		'
Total current liabilities	27,505	16,512	'		'
Long-term debt	707,486	558,161	'		'
Long-term capital leases	679	960	'		'
Partners'/members' equity	876,541	859,609	'		'
Total liabilities and partners' capital	1,612,211	1,435,242	'		'
Co-Issuer [Member]	'	'	'		'
Accounts receivable - related party	1	1	'		'
Total current assets	1	1	'		'
Total assets	1	1	'		'
Partners'/members' equity	1	1	'		'
Total liabilities and partners' capital	1	1	'		'
Guarantor Subsidiaries [Member]	'	'	'		'
Accounts receivable	15,024	14,515	'		'
Accounts receivable - related party	23,783	22,587	'		'
Insurance receivable	3,072	2,920	'		'
Prepaid expenses and other	595	1,357	'		'
Total current assets	42,474	41,379	'		'
Properties, plant and equipment, net	861,728	775,852	'		'
Intangible assets, net	112,178	163,021	'		'
Goodwill	90,978	95,031	'		'
Other assets	993	1,301	'		'
Total assets	1,108,351	1,076,584	'		'
Accrued additions to property, plant and equipment	24,786	3,829	'		'
Capital leases	2,556	3,433	'		'
Accounts payable - related party	401,460	367,682	'		'
Accounts payable, accrued expenses and other liabilities	9,180	11,876	'		'
Total current liabilities	437,982	386,820	'		'
Long-term capital leases	573	2,201	'		'
Asset retirement obligations	13,759	13,188	'		'
Partners'/members' equity	656,037	674,375	'		'
Total liabilities and partners' capital	1,108,351	1,076,584	'		'
Non-Guarantor Subsidiaries [Member]	'	'	'		'
Cash and cash equivalents	1,162	90	5		'
Accounts receivable	11,016	6,513	'		'
Accounts receivable - related party	12	'	'		'
Prepaid expenses and other	22	'	'		'
Total current assets	12,212	6,603	'		'
Investment in unconsolidated affiliate	127,651	'	'		'
Properties, plant and equipment, net	280,075	155,475	'		'
Intangible assets, net	316,702	338,359	'		'
Goodwill	8,618	'	'		'
Deferred financing costs, net	4,429	5,379	'		'
Total assets	749,687	505,816	'		'
Accrued additions to property, plant and equipment	16,462	5,384	'		'
Deferred revenue	2,426	2,634	'		'
Accounts payable - related party	671	108	'		'
Accounts payable, accrued expenses and other liabilities	6,626	2,294	'		'
Total current liabilities	26,185	10,420	'		'
Long-term debt	191,900	127,000	'		'
Asset retirement obligations	874	836	'		'
Partners'/members' equity	530,728	367,560	'		'
Total liabilities and partners' capital	749,687	505,816	'		'
Eliminations [Member]	'	'	'		'
Accounts receivable - related party	-399,501	-365,238	'		'
Total current assets	-399,501	-365,238	'		'
Investment in consolidated affiliates	-1,186,766	-1,041,936	'		'
Total assets	-1,586,267	-1,407,174	'		'
Accounts payable - related party	-399,501	-365,238	'		'
Total current liabilities	-399,501	-365,238	'		'
Partners'/members' equity	-1,186,766	-1,041,936	'		'
Total liabilities and partners' capital	($1,586,267)	($1,407,174)	'		'
[1]	Financial information has been revised to include the results of Crestwood Marcellus Midstream LLC as discussed in Note 2.

Condensed_Consolidating_Financ5

Condensed Consolidating Financial Statements (Schedule Of Condensed Consolidated Statement Of Cash Flows) (Details) (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012
Net cash provided by (used in) operating activities	$81,353	$77,868	[1]
Acquisitions, net of cash acquired	'	-468,987	[1]
Capital expenditures	-164,596	-34,346	[1]
Proceeds from sale of asset	11,000	'
Investment in unconsolidated affiliate	-128,098	'
Other	20	'
Net cash used in investing activities	-281,674	-503,333	[1]
Proceeds from credit facilities	483,400	377,700	[1]
Repayments of credit facilities	-269,000	-337,500	[1]
Payments on capital leases	-3,015	-2,155	[1]
Deferred financing costs paid	-85	-6,489	[1]
Proceeds from issuance of common units, net	118,562	217,508	[1]
Proceeds from issuance of preferred equity of subsidiary, net	96,073	'
Contributions received	'	249,680	[1]
Distribution to General Partner for additional interest in CMM	-129,000	'
Distributions paid	-90,357	-73,653	[1]
Taxes paid for equity-based compensation vesting	-700	-406	[1]
Net cash provided by financing activities	205,878	424,685	[1]
Change in cash and cash equivalents	5,557	-780	[1]
Cash and cash equivalents at beginning of period	111	797	[1]
Cash and cash equivalents at end of period	5,668	17	[1]
Issuer [Member]	'	'
Net cash provided by (used in) operating activities	-18,629	-16,014
Capital expenditures	-573	-659
Capital contributions to consolidated affiliates	-82,025	1,647
Investment in unconsolidated affiliate	'	-131,250
Change in advances to affiliates, net	57,413	-31,730
Net cash used in investing activities	-25,185	-161,992
Proceeds from credit facilities	343,500	350,200
Repayments of credit facilities	-194,000	-329,500
Payments on capital leases	-321	-256
Deferred financing costs paid	-85	-161
Proceeds from issuance of common units, net	118,562	217,508
Contributions received	'	5,930
Distribution to General Partner for additional interest in CMM	-129,000	'
Distributions paid	-90,357	-66,500
Net cash provided by financing activities	48,299	177,221
Change in cash and cash equivalents	4,485	-785
Cash and cash equivalents at beginning of period	21	797
Cash and cash equivalents at end of period	4,506	12
Guarantor Subsidiaries [Member]	'	'
Net cash provided by (used in) operating activities	102,271	86,153
Acquisitions, net of cash acquired	'	-87,269
Capital expenditures	-52,464	-28,309
Proceeds from sale of asset	11,000	'
Net cash used in investing activities	-41,464	-115,578
Payments on capital leases	-2,694	-1,899
Change in advances from affiliates, net	-57,413	31,730
Taxes paid for equity-based compensation vesting	-700	-406
Net cash provided by financing activities	-60,807	29,425
Non-Guarantor Subsidiaries [Member]	'	'
Net cash provided by (used in) operating activities	31,506	9,934
Acquisitions, net of cash acquired	'	-381,718
Capital expenditures	-111,559	-5,378
Investment in unconsolidated affiliate	-128,098	'
Other	20	'
Net cash used in investing activities	-239,637	-387,096
Proceeds from credit facilities	139,900	27,500
Repayments of credit facilities	-75,000	-8,000
Deferred financing costs paid	'	-6,328
Proceeds from issuance of preferred equity of subsidiary, net	96,073	'
Contributions received	82,025	375,000
Distributions paid	-33,795	-11,005
Net cash provided by financing activities	209,203	377,167
Change in cash and cash equivalents	1,072	5
Cash and cash equivalents at beginning of period	90	'
Cash and cash equivalents at end of period	1,162	5
Eliminations [Member]	'	'
Net cash provided by (used in) operating activities	-33,795	-2,205
Capital contributions to consolidated affiliates	82,025	-1,647
Investment in unconsolidated affiliate	'	131,250
Change in advances to affiliates, net	-57,413	31,730
Net cash used in investing activities	24,612	161,333
Contributions received	-82,025	-131,250
Distributions paid	33,795	3,852
Change in advances from affiliates, net	57,413	-31,730
Net cash provided by financing activities	$9,183	($159,128)
[1]	Financial information has been revised to include the results of Crestwood Marcellus Midstream LLC as discussed in Note 2.

Subsequent_Events_Details

Subsequent Events (Details) (USD $)	3 Months Ended		9 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Subsequent Events [Abstract]	'	'	'	'
Revenues	$140	$114	$418	$318
Net income (loss)	$12	$24	$40	$63
Net income per limited partner unit - basic	$0.02	$0.15	$0.17	$0.40
Net income per limited partner unit - diluted	$0.02	$0.15	$0.17	$0.40