Condensed Consolidated Statements of Financial Position (Unaudited) (USD $) In Millions, unless otherwise specified	Sep. 30, 2013		Dec. 31, 2012		Sep. 30, 2012
Current assets
Cash and cash equivalents	$ 131		$ 131		$ 91
Short-term investments	42		58		60
Receivables
Energy marketing receivables	502		677		397
Gas, unbilled and other receivables	341		686		305
Less allowance for uncollectible accounts	32		28		31
Total receivables	811		1,335		671
Inventories, net	797		708		778
Regulatory assets	133		145		158
Derivative instruments	97		130		144
Other current assets	80		161		233
Total current assets	2,091		2,668		2,135
Long-term assets and other deferred debits
Property, plant and equipment	10,920		10,478		10,281
Less accumulated depreciation	2,307		2,131		2,069
Property, plant and equipment, net	8,613		8,347		8,212
Goodwill	1,883		1,837		1,817
Regulatory assets	871		944		994
Intangible assets	180		96		96
Derivative instruments	15		14		15
Other long-term assets and deferred debits	251		235		234
Total long-term assets and other deferred debits	11,813		11,473		11,368
Total assets	13,904	[1]	14,141	[2]	13,503	[1]
Current liabilities
Short-term debt	832		1,377		1,048
Energy marketing trade payable	539		611		444
Accounts payable - trade	304		334		292
Regulatory liabilities	174		161		117
Accrued expenses	157		140		119
Customer deposits and credit balances	140		143		159
Accrued environmental remediation liabilities	48		57		61
Derivative instruments	38		33		37
Accrued regulatory infrastructure program costs	32		121		122
Current portion of long-term debt and capital leases			226		226
Other current liabilities	143		135		139
Total current liabilities	2,407		3,338		2,764
Long-term liabilities and other deferred credits
Long-term debt	3,816		3,327		3,330
Accumulated deferred income taxes	1,587		1,588		1,555
Regulatory liabilities	1,524		1,477		1,465
Accrued environmental remediation liabilities	416		387		365
Accrued retiree welfare benefits	262		268		296
Accrued pension obligations	249		240		213
Derivative instruments	6		6		5
Other long-term liabilities and other deferred credits	74		75		112
Total long-term liabilities and other deferred credits	7,934		7,368		7,341
Total liabilities and other deferred credits	10,341		10,706		10,105
Equity
Common stock, $5 par value; 750,000,000 shares authorized: outstanding: 118,778,298 shares at September 30, 2013, 117,855,075 shares at December 31, 2012 and 117,743,809 shares at September 30, 2012	595		590		590
Additional paid in capital	2,046		2,014		2,012
Retained earnings	1,100		1,035		990
Accumulated other comprehensive loss	(208)	[3]	(218)	[3]	(203)
Treasury shares, at cost: 216,523 shares at September 30, 2013 and December 31, 2012 and September 30, 2012	(8)		(8)		(8)
Total common shareholders’ equity	3,525		3,413		3,381
Noncontrolling interest	38		22		17
Total equity	3,563		3,435		3,398
Total liabilities and equity	$ 13,904		$ 14,141		$ 13,503

[1] Identifiable assets are those used in each segment's operations.

[2] Identifiable assets are those assets used in each segment's operations.

[3] All amounts are net of income taxes. Amounts in parentheses indicate debits to accumulated other comprehensive loss.