XML 82 R69.htm IDEA: XBRL DOCUMENT v3.4.0.3
Variable Interest Entities (Detail) - USD ($)
3 Months Ended
Mar. 31, 2016
Mar. 31, 2015
Dec. 31, 2015
May. 31, 2008
Variable Interest Entity [Line Items]        
Interest Income for WES $ 258,000,000 $ 254,000,000    
Variable Interest Entity, Primary Beneficiary [Member] | Western Gas Partners, LP [Member]        
Variable Interest Entity [Line Items]        
Note receivable       $ 260,000,000
Debt instrument, term 30 years      
Fixed annual rate       6.50%
Interest Income for WES $ 4,000,000 4,000,000    
Deferred purchase price obligation - Anadarko 193,000,000   $ 189,000,000  
Above-market component of swap extensions with Anadarko $ 4,000,000 $ 0