XML 65 R46.htm IDEA: XBRL DOCUMENT v3.3.1.900
Summary of Significant Accounting Policies - Minimum Volume Commitments (Details) - Minimum Volume Commitments - USD ($)
$ in Millions
Dec. 31, 2015
Dec. 31, 2014
Minimum Volume Commitments    
Total counterparty deficiencies $ 33  
Deferred revenue 17 $ 4
Accrued deficiencies not yet billed or collected $ 16