Long-Term Debt and Interest Expense - Additional Information (Detail) (USD $)	12 Months Ended			0 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Mar. 07, 2014	Aug. 14, 2013	Apr. 19, 2011	Dec. 19, 2012	Jan. 11, 2012	Feb. 02, 2015	Feb. 03, 2015
Line Of Credit Facility [Line Items]
Revolving credit facility termination date	Feb. 02, 2015
Maturity date of credit facilities post-merger	Aug. 03, 2015
Methods of calculating interest rate	Each time funds are borrowed under the credit facility, the borrower may choose from two methods of calculating interest: a fluctuating base rate equal to an alternate base rate plus an applicable margin or a periodic fixed rate equal to LIBOR plus an applicable margin
Line of credit facility, covenant terms	• The ratio of debt to EBITDA (each as defined in the credit facility) to be no greater than 5 to 1, except for the fiscal quarter and the two following fiscal quarters in which one or more acquisitions has been executed, in which case the ratio of debt to EBITDA is to be no greater than 5.5 to 1.
Debt to capitalization ratio	65.00%
Amended and restated debt security, maximum outstanding amount related to merger.									$ 3,000,000,000
Notes Issued At Price Of Percent Of Principal Amount					101.50%
Capitalized interest	25,600,000	43,900,000	14,600,000
Access Midstream Long-Term Incentive Plan
Line Of Credit Facility [Line Items]
Percentage of ownership interest	100.00%
Senior Notes
Line Of Credit Facility [Line Items]
Senior notes covenants	The indentures governing the 2024 Notes, the 2023 Notes, the 2022 Notes and the 2021 Notes contain covenants that, among other things, limit the Partnership’s ability and the ability of certain of the Partnership’s subsidiaries to: (1) sell assets including equity interests in its subsidiaries; (2) pay distributions on, redeem or purchase the Partnership’s units, or redeem or purchase the Partnership’s subordinated debt; (3) make investments; (4) incur or guarantee additional indebtedness or issue preferred units; (5) create or incur certain liens; (6) enter into agreements that restrict distributions or other payments from certain subsidiaries to the Partnership; (7) consolidate, merge or transfer all or substantially all of the Partnership’s or certain of the Partnership’s subsidiaries’ assets; (8) engage in transactions with affiliates; and (9) create unrestricted subsidiaries. These covenants are subject to important exceptions and qualifications. If the 2024 Notes, 2023 Notes, 2022 Notes or the 2021 Notes achieve an investment grade rating from either of Moody’s Investors Service, Inc. or Standard & Poor’s Ratings Services and no default, as defined in the indentures, has occurred or is continuing, many of these covenants will terminate. Following the Merger, the senior notes noted above achieved an investment grade rating and therefore many of the covenants terminated. There were no other significant changes to these senior notes as a result of the Merger.
4.875 Percent Senior Notes due March 2024
Line Of Credit Facility [Line Items]
Senior Notes issued through private placement				750,000,000
Debt, interest rate				4.875%
Debt issuance cost				8,900,000
Notes maturity date				Mar. 15, 2024
Interest payable on Senior Notes				March 15 and September 15
Debt redemption date	Mar. 15, 2019
Debt redemption description				In addition, the Partnership may redeem up to 35 percent of the 2024 Notes prior to March 15, 2017 under certain circumstances with the net cash proceeds from certain equity offerings.
5.875 Percent Senior Notes due April 2021
Line Of Credit Facility [Line Items]
Senior Notes issued through private placement					400,000,000
Debt, interest rate					5.875%	5.875%
Debt issuance cost					5,800,000	8,200,000
Net proceeds of additional notes issued					400,800,000
Proceeds from issuance of private placement						350,000,000
Notes maturity date						Apr. 15, 2021
Interest payable on Senior Notes						April 15 and October 15
Debt redemption date						Apr. 15, 2015
Debt redemption description						In addition, the Partnership may redeem up to 35 percent of the 2021 Notes and Additional Notes prior to April 15, 2014 under certain circumstances with the net cash proceeds from certain equity offerings.
Interest payable on Senior Notes, beginning date						Oct. 15, 2011
4.875 Percent Senior Notes due May 2023
Line Of Credit Facility [Line Items]
Senior Notes issued through private placement							1,400,000,000
Debt, interest rate							4.875%
Debt issuance cost							25,900,000
Notes maturity date							May 15, 2023
Interest payable on Senior Notes							May 15 and November 15
Debt redemption date							Dec. 15, 2017
Debt redemption description							In addition, the Partnership may redeem up to 35 percent of the 2023 Notes prior to December 15, 2015 under certain circumstances with the net cash proceeds from certain equity offerings.
6.125 Percent Senior Notes due July 2022
Line Of Credit Facility [Line Items]
Senior Notes issued through private placement								750,000,000
Debt, interest rate								6.125%
Debt issuance cost								13,800,000
Notes maturity date								Jul. 15, 2022
Interest payable on Senior Notes								January 15 and July 15
Debt redemption date								Jan. 15, 2017
Debt redemption description								In addition, the Partnership may redeem up to 35 percent of the 2022 Notes prior to January 15, 2015 under certain circumstances with the net cash proceeds from certain equity offerings.
Subsequent Event
Line Of Credit Facility [Line Items]
Outstanding letter of credit									2,310,000
Short-term credit facility										1,500,000,000
Option one
Line Of Credit Facility [Line Items]
Maturity date of credit facilities post-merger	Feb. 02, 2016
Libor Plus Rate
Line Of Credit Facility [Line Items]
Debt Instrument variable rate	1.00%
Minimum | Federal Funds Effective Rate Plus
Line Of Credit Facility [Line Items]
Debt Instrument variable rate	0.50%
Minimum | Libor Plus Rate
Line Of Credit Facility [Line Items]
Debt Instrument variable rate	2.16%
Minimum | London Inter Bank Offered Rate Plus
Line Of Credit Facility [Line Items]
Debt Instrument variable rate	0.50%
Minimum | Eurodollar rate plus a margin
Line Of Credit Facility [Line Items]
Debt Instrument variable rate	1.50%
Maximum | 4.875 Percent Senior Notes due March 2024
Line Of Credit Facility [Line Items]
Debt redemption date				Mar. 15, 2017
Debt redemption percentage				35.00%
Maximum | 5.875 Percent Senior Notes due April 2021
Line Of Credit Facility [Line Items]
Debt redemption date						Apr. 15, 2014
Debt redemption percentage						35.00%
Maximum | 4.875 Percent Senior Notes due May 2023
Line Of Credit Facility [Line Items]
Debt redemption date							Dec. 15, 2015
Debt redemption percentage							35.00%
Maximum | 6.125 Percent Senior Notes due July 2022
Line Of Credit Facility [Line Items]
Debt redemption date								Jan. 15, 2015
Debt redemption percentage								35.00%
Maximum | Scenario One
Line Of Credit Facility [Line Items]
Debt to ebitda ratio	5.00%
Maximum | Scenario Two
Line Of Credit Facility [Line Items]
Debt to ebitda ratio	5.50%
Maximum | Subsequent Event
Line Of Credit Facility [Line Items]
Additional borrowing capacity									500,000,000
Maximum | Libor Plus Rate
Line Of Credit Facility [Line Items]
Debt Instrument variable rate	2.42%
Maximum | London Inter Bank Offered Rate Plus
Line Of Credit Facility [Line Items]
Debt Instrument variable rate	1.50%
Maximum | Eurodollar rate plus a margin
Line Of Credit Facility [Line Items]
Debt Instrument variable rate	2.50%
Revolving Credit Facility
Line Of Credit Facility [Line Items]
Revolving credit facility	640,000,000	343,500,000
Amended Revolving Credit Facility Post Merger
Line Of Credit Facility [Line Items]
Maturity date of credit facilities post-merger	Feb. 02, 2020
Amended Revolving Credit Facility Post Merger | Subsequent Event
Line Of Credit Facility [Line Items]
Revolving credit facility									3,500,000,000
Amended Revolving Credit Facility Post Merger | Option one
Line Of Credit Facility [Line Items]
Maturity date of credit facilities post-merger	Feb. 02, 2022
Swing Line Loan | Subsequent Event
Line Of Credit Facility [Line Items]
Revolving credit facility									150,000,000
Letter of Credit | Subsequent Event
Line Of Credit Facility [Line Items]
Revolving credit facility									$ 1,125,000,000