XML 38 R28.htm IDEA: XBRL DOCUMENT v3.5.0.2
Fair Value of Financial Instruments Financial Assets and Liabilities Recognized at Fair Value (Details) - USD ($)
$ in Millions
Sep. 30, 2016
Dec. 31, 2015
Debt securities:    
Domestic government $ 12 $ 14
Corporate credit 9 8
Money market funds 20 18
Investments, Fair Value Disclosure 2 2
Non-qualified benefit plan trust: (2)    
Domestic 4 3
Debt securities—domestic government 1 1
Alternative Investments, Fair Value Disclosure 1 1
Assets from price risk management activities: (1) (3)    
Electricity 2 7
Natural gas 5 3
Total 56 57
Liabilities from price risk management activities: (1) (3)    
Electricity 143 133
Natural gas 86 158
Total 229 291
Fair Value, Inputs, Level 1 [Member]    
Debt securities:    
Domestic government 2 6
Corporate credit 0 0
Non-qualified benefit plan trust: (2)    
Domestic 4 3
Debt securities—domestic government 1 1
Assets from price risk management activities: (1) (3)    
Electricity 0 0
Natural gas 0 0
Total 7 10
Liabilities from price risk management activities: (1) (3)    
Electricity 0 0
Natural gas 0 0
Total 0 0
Fair Value, Inputs, Level 2 [Member]    
Debt securities:    
Domestic government 10 8
Corporate credit 9 8
Non-qualified benefit plan trust: (2)    
Domestic 0 0
Debt securities—domestic government 0 0
Assets from price risk management activities: (1) (3)    
Electricity 2 7
Natural gas 5 3
Total 26 26
Liabilities from price risk management activities: (1) (3)    
Electricity 4 28
Natural gas 65 144
Total 69 172
Fair Value, Inputs, Level 3 [Member]    
Debt securities:    
Domestic government 0 0
Corporate credit 0 0
Non-qualified benefit plan trust: (2)    
Domestic 0 0
Debt securities—domestic government 0 0
Assets from price risk management activities: (1) (3)    
Electricity 0 0
Natural gas 0 0
Total 0 0
Liabilities from price risk management activities: (1) (3)    
Electricity 139 105
Natural gas 21 14
Total 160 119
Reported Value Measurement [Member]    
Debt securities:    
Money market funds 20 18
Investments, Fair Value Disclosure 2 2
Non-qualified benefit plan trust: (2)    
Alternative Investments, Fair Value Disclosure 1 1
Assets from price risk management activities: (1) (3)    
Total $ 23 $ 21