Subsequent Events	12 Months Ended
Dec. 31, 2016
Subsequent Events [Abstract]
Subsequent Events	14. SUBSEQUENT EVENTS On February 9, 2017, WES entered into an agreement with Williams Partners L.P. (“WPZ”) whereby WES will acquire WPZ’s 50% non-operated interest in the DBJV system in exchange for WES’s 33.75% interest in the Non-Operated Marcellus Interest systems and $155.0 million in cash. WES currently holds a 50% interest in, and operates, the DBJV system. WES expects to fund the cash consideration through borrowings under its RCF and to close the transaction, subject to standard closing conditions and adjustments, in the first quarter of 2017. Effective February 13, 2017, Donald R. Sinclair resigned from his positions as President and Chief Executive Officer and as a member of the Board of Directors of WGP’s general partner. Also on February 13, 2017, the Board of Directors appointed Benjamin M. Fink to be President and Chief Executive Officer of WGP’s general partner and also appointed him to the Board of Directors. In addition, on February 13, 2017, the Board of Directors appointed Craig W. Collins as Senior Vice President and Chief Operating Officer of the general partner and Philip H. Peacock as Senior Vice President, General Counsel and Corporate Secretary of the general partner. On February 21, 2017, Anadarko notified WES that it elected to defer the conversion date of the WES Class C units from December 31, 2017 to March 1, 2020. Pursuant to a Consent and Conversion Agreement (the “Conversion Agreement”), dated February 22, 2017, among WES and the holders of the Series A Preferred units, WES and the holders of the Series A Preferred units have agreed to convert on a one-for-one basis 50% of the outstanding Series A Preferred units into WES common units effective as of February 23, 2017, and convert the remaining Series A Preferred units on May 2, 2017 (collectively, the “Early Conversion”). The WES common units to be issued in connection with the Early Conversion will be undertaken in reliance upon an exemption from the registration requirements of the Securities Act of 1933, as amended, pursuant to Section 4(a)(2) thereof. In connection with the Early Conversion, WES (i) agreed to amend the registration rights agreement with the holders of the Series A Preferred units through the Conversion Agreement and use its commercially reasonable efforts to file a registration statement by March 10, 2017, to permit the public resale of the WES common units received by the holders of the Series A Preferred units and for such registration statement to be declared effective no later than March 14, 2018, and (ii) entered into an amendment to WES’s limited partnership agreement (the “Second LPA Amendment”) on February 22, 2017, for certain matters related to the tax basis of the WES common units received in the Early Conversion.

14. SUBSEQUENT EVENTS

On February 9, 2017, WES entered into an agreement with Williams Partners L.P. (“WPZ”) whereby WES will acquire WPZ’s 50% non-operated interest in the DBJV system in exchange for WES’s 33.75% interest in the Non-Operated Marcellus Interest systems and $155.0 million in cash. WES currently holds a 50% interest in, and operates, the DBJV system. WES expects to fund the cash consideration through borrowings under its RCF and to close the transaction, subject to standard closing conditions and adjustments, in the first quarter of 2017.

Effective February 13, 2017, Donald R. Sinclair resigned from his positions as President and Chief Executive Officer and as a member of the Board of Directors of WGP’s general partner. Also on February 13, 2017, the Board of Directors appointed Benjamin M. Fink to be President and Chief Executive Officer of WGP’s general partner and also appointed him to the Board of Directors. In addition, on February 13, 2017, the Board of Directors appointed Craig W. Collins as Senior Vice President and Chief Operating Officer of the general partner and Philip H. Peacock as Senior Vice President, General Counsel and Corporate Secretary of the general partner.

On February 21, 2017, Anadarko notified WES that it elected to defer the conversion date of the WES Class C units from December 31, 2017 to March 1, 2020.

Pursuant to a Consent and Conversion Agreement (the “Conversion Agreement”), dated February 22, 2017, among WES and the holders of the Series A Preferred units, WES and the holders of the Series A Preferred units have agreed to convert on a one-for-one basis 50% of the outstanding Series A Preferred units into WES common units effective as of February 23, 2017, and convert the remaining Series A Preferred units on May 2, 2017 (collectively, the “Early Conversion”). The WES common units to be issued in connection with the Early Conversion will be undertaken in reliance upon an exemption from the registration requirements of the Securities Act of 1933, as amended, pursuant to Section 4(a)(2) thereof. In connection with the Early Conversion, WES (i) agreed to amend the registration rights agreement with the holders of the Series A Preferred units through the Conversion Agreement and use its commercially reasonable efforts to file a registration statement by March 10, 2017, to permit the public resale of the WES common units received by the holders of the Series A Preferred units and for such registration statement to be declared effective no later than March 14, 2018, and (ii) entered into an amendment to WES’s limited partnership agreement (the “Second LPA Amendment”) on February 22, 2017, for certain matters related to the tax basis of the WES common units received in the Early Conversion.