CONSOLIDATED STATEMENTS OF INCOME - USD ($) shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Operating revenues
Total operating revenues	$ 11,537	$ 11,404	$ 11,107
Operating expenses
Electric fuel and purchased power	3,854	3,757	3,718
Cost of natural gas sold and transported	843	823	733
Cost of sales — other	35	34	36
Operating and maintenance expenses	2,352	2,270	2,300
Conservation and demand side management program expenses	290	273	245
Depreciation and amortization	1,642	1,479	1,303
Taxes (other than income taxes)	556	545	532
Total operating expenses	9,572	9,181	8,867
Operating income	1,965	2,223	2,240
Other income, net	(14)	(10)	(18)
Income (Loss) from Equity Method Investments	35	30	42
Allowance for funds used during construction — equity	108	75	60
Interest charges and financing costs
Interest charges — includes other financing costs of $25, $24 and $25, respectively	700	663	647
Allowance for funds used during construction — debt	(48)	(35)	(27)
Total interest charges and financing costs	652	628	620
Income before income taxes	1,442	1,690	1,704
Income taxes	181	542	581
Net income	$ 1,261	$ 1,148	$ 1,123
Weighted average common shares outstanding:
Basic (in shares)	511	509	509
Diluted (in shares)	511	509	509
Earnings per average common share:
Basic (in dollars per share)	$ 2.47	$ 2.26	$ 2.21
Diluted (in dollars per share)	$ 2.47	$ 2.25	$ 2.21
Electricity, US Regulated [Member]
Operating revenues
Total operating revenues	$ 9,719	$ 9,676	$ 9,500
Natural Gas, US Regulated [Member]
Operating revenues
Total operating revenues	1,739	1,650	1,531
Product and Service, Other [Member]
Operating revenues
Total operating revenues	$ 79	$ 78	$ 76