Consolidated Balance Sheets - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014
Current assets
Cash and cash equivalents	$ 19	$ 31
Short-term investments	8	8
Receivables
Energy marketing	445	779
Natural gas	266	391
Unbilled revenues	140	256
Other	110	150
Less allowance for uncollectible accounts	29	35
Total receivables, net	932	1,541
Inventories
Natural gas	622	694
Other	29	22
Total inventories	651	716
Prepaid expenses	218	223
Derivative instruments	206	245
Regulatory assets	68	83
Other	13	39
Total current assets	2,115	2,886
Long-term assets and other deferred debits
Property, plant and equipment	12,566	11,552
Less accumulated depreciation	2,775	2,462
Property, plant and equipment, net	9,791	9,090
Goodwill	1,813	1,827
Regulatory assets	670	631
Intangible assets	109	125
Long-term investments	103	105
Pension assets	78	97
Derivative instruments	12	42
Other	63	85
Total long-term assets and other deferred debits	12,639	12,002
Total assets	14,754	14,888
Current liabilities
Short-term debt	1,010	1,175
Current portion of long-term debt	545	200
Energy marketing trade payables	418	777
Other accounts payable – trade	255	312
Customer deposits and credit balances	165	125
Regulatory liabilities	134	112
Accrued wages and salaries	92	97
Accrued environmental remediation liabilities	67	87
Accrued taxes	59	79
Accrued interest	49	53
Derivative instruments	44	88
Current deferred income taxes	31	2
Other	131	112
Total current liabilities	3,000	3,219
Long-term liabilities and other deferred credits
Long-term debt	3,275	3,581
Accumulated deferred income taxes	1,912	1,724
Regulatory liabilities	1,611	1,601
Accrued pension and retiree welfare benefits	515	525
Accrued environmental remediation liabilities	364	327
Other	102	83
Total long-term liabilities and other deferred credits	7,779	7,841
Total liabilities and other deferred credits	$ 10,779	$ 11,060
Commitments, guarantees and contingencies (see Note 12)
Equity
Common stock, $5 par value; 750,000,000 shares authorized; outstanding: 120,376,721 shares at December 31, 2015 and 119,647,149 shares at December 31, 2014	$ 603	$ 599
Additional paid-in capital	2,099	2,087
Retained earnings	1,421	1,312
Accumulated other comprehensive loss	(186)	(206)
Treasury shares, at cost: 216,523 shares at December 31, 2015 and 2014	(8)	(8)
Total common shareholders’ equity	3,929	3,784
Noncontrolling interest	46	44
Total equity	3,975	3,828
Total liabilities and equity	$ 14,754	$ 14,888