Equity and Partners' Capital - Equity Offerings Table (details) (Western Gas Partners [Member], USD $)	1 Months Ended											3 Months Ended		12 Months Ended			3 Months Ended		12 Months Ended		3 Months Ended		12 Months Ended
	Dec. 31, 2013		May 31, 2013		Jan. 31, 2014 Option on Securities [Member]	Jan. 31, 2014 Common Units [Member] Option on Securities [Member]	May 31, 2013 Common Units [Member] Option on Securities [Member]	Dec. 31, 2013 General Partner [Member]		May 31, 2013 General Partner [Member]		Mar. 31, 2014 Continuous Offering Program [Member]		Dec. 31, 2013 Continuous Offering Program [Member]		Aug. 31, 2012 Continuous Offering Program [Member]	Mar. 31, 2014 Continuous Offering Program [Member] Common Units [Member]		Dec. 31, 2013 Continuous Offering Program [Member] Common Units [Member]		Mar. 31, 2014 Continuous Offering Program [Member] General Partner [Member]		Dec. 31, 2013 Continuous Offering Program [Member] General Partner [Member]
Capital Unit [Line Items]
Common units Issued	4,800,000	[1]	7,015,000	[2]		300,000	915,000										0	[3]	685,735	[4]
General partner units issued								97,959	[1],[5]	143,163	[2],[5]										0	[3],[5]	13,996	[4],[5]
Price per unit	$ 61.51	[1]	$ 61.18	[2]
Underwriting discount and other offering expenses	$ 9,395,000	[1]	$ 13,203,000	[2]								$ 0	[3]	$ 965,000	[4]
Net proceeds to WES	291,879,000	[1]	424,733,000	[2]	18,200,000							0	[3]	41,603,000	[4]
Average price per unit												$ 0.00	[3]	$ 60.84	[4]
Table Text Block Supplement [Abstract]
Maximum aggregate principal of common stock																125,000,000
Gross proceeds														$ 42,600,000

[1] Includes the issuance of 300,000 WES common units on January 3, 2014, pursuant to the partial exercise of the underwriters’ over-allotment option granted in connection with the December 2013 equity offering. Net proceeds from this partial exercise (including WES GP’s proportionate capital contribution) were $18.2 million.

[2] Includes the issuance of 915,000 WES common units pursuant to the full exercise of the underwriters’ over-allotment option granted in connection with the May 2013 equity offering.

[3] During the three months ended March 31, 2014, WES did not issue any common units under the Continuous Offering Program.

[4] Represents common and general partner units of WES issued during the year ended December 31, 2013, pursuant to WES’s registration statement filed with the SEC in August 2012 authorizing the issuance of up to an aggregate of $125.0 million of common units (the “Continuous Offering Program”). Gross proceeds generated (including WES GP’s proportionate capital contributions) were $42.6 million. The price per unit in the table above represents an average price for all issuances under the Continuous Offering Program during 2013.

[5] Represents general partner units of WES issued to WES GP in exchange for WES GP’s proportionate capital contribution to maintain its 2.0% general partner interest.