Consolidated Statements of Operations (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Operating revenue:
Energy	$ 10,236	$ 10,181	$ 10,107
Real estate	1,312	992	1,020
Total operating revenue	11,548	11,173	11,127
Energy:
Cost of sales	3,517	3,648	3,890
Operating expense	2,778	2,544	2,470
Depreciation and amortization	1,436	1,329	1,262
Real estate	1,250	968	1,003
Total operating costs and expenses	8,981	8,489	8,625
Operating income (loss)	2,567	2,684	2,502
Other income (expense):
Interest expense	(1,176)	(1,196)	(1,225)
Capitalized interest	54	40	54
Allowance for equity AFUDC	74	72	89
Other, net	56	(7)	45
Total other income (expense)	(992)	(1,091)	(1,037)
Income (loss) before income tax expense (benefit) and equity income	1,575	1,593	1,465
Income tax expense	148	294	198
Equity income	68	53	43
Net income	1,495	1,352	1,310
Net income attributable to noncontrolling interests	23	21	72
Net income attributable to MEHC shareholders	$ 1,472	$ 1,331	$ 1,238