Leases Operating Lease Costs (Details) $ in Millions	3 Months Ended
	Mar. 31, 2019 USD ($)
Operating Lease Costs
Long-term Lease Costs	$ 10
Short-term Lease Costs	7
Variable Lease Costs	3
Total Operating Lease Costs	20
Cash Paid for Amounts Included in the Measurement of Operating Lease Liabilities	$ 10
Weighted Average Remaining Lease Term in Years	13 years
Weighted Average Discount Rate	4.20%
Pse And G
Operating Lease Costs
Long-term Lease Costs	$ 4
Short-term Lease Costs	5
Variable Lease Costs	0
Total Operating Lease Costs	9
Cash Paid for Amounts Included in the Measurement of Operating Lease Liabilities	$ 4
Weighted Average Remaining Lease Term in Years	13 years
Weighted Average Discount Rate	3.70%
Power
Operating Lease Costs
Long-term Lease Costs	$ 2
Short-term Lease Costs	2
Variable Lease Costs	0
Total Operating Lease Costs	4
Cash Paid for Amounts Included in the Measurement of Operating Lease Liabilities	$ 2
Weighted Average Remaining Lease Term in Years	20 years
Weighted Average Discount Rate	5.00%
Other
Operating Lease Costs
Long-term Lease Costs	$ 4
Short-term Lease Costs	0
Variable Lease Costs	3
Total Operating Lease Costs	7
Cash Paid for Amounts Included in the Measurement of Operating Lease Liabilities	$ 4
Weighted Average Remaining Lease Term in Years	11 years
Weighted Average Discount Rate	4.20%