XML 314 R266.htm IDEA: XBRL DOCUMENT v3.8.0.1
Commitments and Contingencies - NPC - Commitments Table (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Contractual Obligation [Line Items]      
Contractual Obligation, Due in Next Twelve Months $ 3,644    
Contractual Obligation, Due in Second Year 2,100    
Contractual Obligation, Due in Third Year 1,819    
Contractual Obligation, Due in Fourth Year 1,562    
Contractual Obligation, Due in Fifth Year 1,419    
Contractual Obligation, Due after Fifth Year 12,396    
Contractual Obligation 22,940    
Fuel, capacity and transmission contract commitments [Member]      
Contractual Obligation [Line Items]      
Purchase Obligation, Due in Next Twelve Months 2,098    
Purchase Obligation, Due in Second Year 1,637    
Purchase Obligation, Due in Third Year 1,435    
Purchase Obligation, Due in Fourth Year 1,210    
Purchase Obligation, Due in Fifth Year 1,055    
Purchase Obligation, Due after Fifth Year 10,044    
Purchase Obligation 17,479    
Maintenance, service and other contracts [Member]      
Contractual Obligation [Line Items]      
Purchase Obligation, Due in Next Twelve Months 246    
Purchase Obligation, Due in Second Year 249    
Purchase Obligation, Due in Third Year 238    
Purchase Obligation, Due in Fourth Year 231    
Purchase Obligation, Due in Fifth Year 253    
Purchase Obligation, Due after Fifth Year 1,055    
Purchase Obligation 2,272    
Nevada Power Company [Member]      
Contractual Obligation [Line Items]      
Contractual Obligation, Due in Next Twelve Months 644    
Contractual Obligation, Due in Second Year 516    
Contractual Obligation, Due in Third Year 450    
Contractual Obligation, Due in Fourth Year 449    
Contractual Obligation, Due in Fifth Year 449    
Contractual Obligation, Due after Fifth Year 5,723    
Contractual Obligation 8,231    
Rent expense for power purchase agreements meeting definition of operating lease 310 $ 302 $ 264
Operating Lease and Easement, Expense 9 $ 13 $ 11
Nevada Power Company [Member] | Fuel, capacity and transmission contract commitments [Member]      
Contractual Obligation [Line Items]      
Purchase Obligation, Due in Next Twelve Months 591    
Purchase Obligation, Due in Second Year 450    
Purchase Obligation, Due in Third Year 377    
Purchase Obligation, Due in Fourth Year 378    
Purchase Obligation, Due in Fifth Year 380    
Purchase Obligation, Due after Fifth Year 5,208    
Purchase Obligation 7,384    
Nevada Power Company [Member] | Fuel, capacity and transmission contract commitments, Not commercially operable [Member]      
Contractual Obligation [Line Items]      
Purchase Obligation, Due in Next Twelve Months 0    
Purchase Obligation, Due in Second Year 15    
Purchase Obligation, Due in Third Year 22    
Purchase Obligation, Due in Fourth Year 24    
Purchase Obligation, Due in Fifth Year 25    
Purchase Obligation, Due after Fifth Year 421    
Purchase Obligation 507    
Nevada Power Company [Member] | Operating Leases and easements [Member]      
Contractual Obligation [Line Items]      
Purchase Obligation, Due in Next Twelve Months 7    
Purchase Obligation, Due in Second Year 7    
Purchase Obligation, Due in Third Year 8    
Purchase Obligation, Due in Fourth Year 8    
Purchase Obligation, Due in Fifth Year 7    
Purchase Obligation, Due after Fifth Year 54    
Purchase Obligation 91    
Nevada Power Company [Member] | Maintenance, service and other contracts [Member]      
Contractual Obligation [Line Items]      
Purchase Obligation, Due in Next Twelve Months 46    
Purchase Obligation, Due in Second Year 44    
Purchase Obligation, Due in Third Year 43    
Purchase Obligation, Due in Fourth Year 39    
Purchase Obligation, Due in Fifth Year 37    
Purchase Obligation, Due after Fifth Year 40    
Purchase Obligation $ 249