Condensed Consolidated Statements of Financial Position (Unaudited) - USD ($) $ in Millions	Jun. 30, 2015	Dec. 31, 2014	Jun. 30, 2014
Current assets
Cash and cash equivalents	$ 25	$ 31	$ 122
Receivables
Natural gas, unbilled revenues and other	445	797	520
Energy marketing	430	779	677
Less allowance for uncollectible accounts	46	35	51
Total receivables, net	829	1,541	1,146
Inventories
Natural gas	395	694	441
Other	26	22	19
Total inventories	421	716	460
Derivative instruments	158	245	105
Prepaid expenses	51	223	67
Regulatory assets	48	83	165
Assets held for sale			257
Other	40	47	58
Total current assets	1,572	2,886	2,380
Long-term assets and other deferred debits
Property, plant and equipment	11,903	11,552	11,188
Less accumulated depreciation	2,524	2,462	2,400
Property, plant and equipment, net	9,379	9,090	8,788
Goodwill	1,827	1,827	1,827
Regulatory assets	642	631	726
Intangible assets	112	125	135
Other	303	329	303
Total long-term assets and other deferred debits	12,263	12,002	11,779
Total assets	13,835	14,888	14,159
Current liabilities
Short-term debt	459	1,175	448
Energy marketing trade payables	455	777	724
Other accounts payable – trade	272	312	319
Accrued expenses	183	229	213
Regulatory liabilities	154	112	149
Current portion of long-term debt	125	200	200
Customer deposits and credit balances	115	125	107
Accrued environmental remediation liabilities	83	87	90
Derivative instruments	43	88	50
Temporary LIFO liquidation	38		116
Liabilities held for sale			39
Other	120	114	140
Total current liabilities	2,047	3,219	2,595
Long-term liabilities and other deferred credits
Long-term debt	3,452	3,581	3,585
Accumulated deferred income taxes	1,780	1,724	1,675
Regulatory liabilities	1,622	1,601	1,565
Accrued pension and retiree welfare benefits	526	525	405
Accrued environmental remediation liabilities	346	327	379
Other	73	83	95
Total long-term liabilities and other deferred credits	7,799	7,841	7,704
Total liabilities and other deferred credits	$ 9,846	$ 11,060	$ 10,299
Commitments, guarantees and contingencies (see Note 10)
Equity
Common stock, $5 par value; 750,000,000 shares authorized; outstanding: 120,081,995 shares at June 30, 2015, 119,647,149 shares at December 31, 2014, and 119,464,063 shares at June 30, 2014	$ 601	$ 599	$ 598
Additional paid-in capital	2,099	2,087	2,073
Retained earnings	1,425	1,312	1,288
Accumulated other comprehensive loss	(169)	(206)	(133)
Treasury shares, at cost: 216,523 shares at June 30, 2015, December 31, 2014, and June 30, 2014	(8)	(8)	(8)
Total common shareholders’ equity	3,948	3,784	3,818
Noncontrolling interest	41	44	42
Total equity	3,989	3,828	3,860
Total liabilities and equity	$ 13,835	$ 14,888	$ 14,159