CONSOLIDATED STATEMENTS OF INCOME - USD ($) shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Operating revenues
Electric	$ 9,676	$ 9,500	$ 9,276
Natural gas	1,650	1,531	1,672
Other	78	76	76
Total operating revenues	11,404	11,107	11,024
Operating expenses
Electric fuel and purchased power	3,757	3,718	3,763
Cost of natural gas sold and transported	823	733	905
Cost of sales — other	34	36	36
Operating and maintenance expenses	2,303	2,326	2,330
Conservation and demand side management program expenses	273	245	225
Depreciation and amortization	1,479	1,303	1,124
Taxes (other than income taxes)	545	532	512
Loss on Monticello life cycle management/extended power uprate project	0	0	129
Total operating expenses	9,214	8,893	9,024
Operating income	2,190	2,214	2,000
Other income, net	23	8	6
Equity earnings of unconsolidated subsidiaries	30	42	34
Allowance for funds used during construction — equity	75	60	56
Interest charges and financing costs
Interest charges — includes other financing costs of $24, $25 and $24, respectively	663	647	595
Allowance for funds used during construction — debt	(35)	(27)	(26)
Total interest charges and financing costs	628	620	569
Income before income taxes	1,690	1,704	1,527
Income taxes	542	581	543
Net income	$ 1,148	$ 1,123	$ 984
Weighted average common shares outstanding:
Basic (in shares)	509.0	508.8	507.8
Diluted (in shares)	509.1	509.0	508.2
Earnings per average common share:
Basic (in dollars per share)	$ 2.26	$ 2.21	$ 1.94
Diluted (in dollars per share)	2.25	2.21	1.94
Cash dividends declared per common share (in dollars per share)	$ 1.44	$ 1.36	$ 1.28