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Transactions with Affiliates - LTIP Award Activity Tables (Details) - $ / shares
12 Months Ended
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
Related Party Transaction [Line Items]      
Value per unit of phantom units outstanding at beginning of year $ 47.20 $ 43.10 $ 39.19
Value per unit of phantom units vested during the period 47.20 44.44 37.32
Value per unit of phantom units granted during the period 39.78 62.21 51.19
Value per unit of phantom units outstanding at end of year $ 39.78 $ 47.20 $ 43.10
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]      
Phantom units outstanding at beginning of year 12,537 22,236 36,238
Phantom units vested (12,537) (13,317) (18,400)
Phantom units granted 5,658 3,618 4,398
Phantom units outstanding at end of year 5,658 12,537 22,236
Western Gas Partners, LP [Member]      
Related Party Transaction [Line Items]      
Value per unit of phantom units outstanding at beginning of year $ 68.78 $ 60.74 $ 49.47
Value per unit of phantom units vested during the period 68.78 60.69 49.55
Value per unit of phantom units granted during the period 49.30 69.10 68.14
Value per unit of phantom units outstanding at end of year $ 49.30 $ 68.78 $ 60.74
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]      
Phantom units outstanding at beginning of year 5,477 9,522 16,844
Phantom units vested (5,477) (9,257) (13,122)
Phantom units granted 7,304 5,212 5,800
Phantom units outstanding at end of year 7,304 5,477 9,522