Equity and Partners' Capital - Limited Partner and General Partner Units (details) (Western Gas Partners [Member])			3 Months Ended			3 Months Ended			3 Months Ended
	Mar. 31, 2013	Dec. 31, 2012	Mar. 31, 2013 Non-Operated Marcellus Interest [Member]	Mar. 31, 2013 Common [Member]	Dec. 31, 2012 Common [Member]	Mar. 31, 2013 Common [Member] Non-Operated Marcellus Interest [Member]	Mar. 31, 2013 General Partner Member	Dec. 31, 2012 General Partner Member	Mar. 31, 2013 General Partner Member Non-Operated Marcellus Interest [Member]
Capital Unit [Line Items]
Balance	107,254,778	106,796,483		105,109,682	104,660,553		2,145,096	2,135,930
Acquisition			458,295			449,129			9,166
Balance	107,254,778	106,796,483		105,109,682	104,660,553		2,145,096	2,135,930