Consolidated Balance Sheets Consolidated Balance Sheets (USD $) In Millions, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Current assets:
Cash and cash equivalents	$ 133	$ 80
Accounts receivable, net	568	671
Inventories:
Materials and supplies	208	202
Fuel	270	266
Deferred income taxes	90	112
Regulatory assets	67	62
Other current assets	69	75
Total current assets	1,405	1,468
Property, plant and equipment, net	18,134	18,057
Regulatory assets	1,737	1,773
Other assets	425	430
Total assets	21,701	21,728
Current liabilities:
Accounts payable	412	467
Income taxes payable	16	48
Accrued employee expenses	106	77
Accrued interest	97	113
Accrued property and other taxes	82	54
Current portion of long-term debt and capital lease obligations	285	267
Regulatory liabilities	64	62
Other current liabilities	201	196
Total current liabilities	1,263	1,284
Regulatory liabilities	861	851
Long-term debt and capital lease obligations	6,565	6,594
Deferred income taxes	4,201	4,168
Other long-term liabilities	1,158	1,187
Total liabilities	14,048	14,084
Commitments and contingencies (Note 9)
Shareholders' equity:
Preferred stock	41	41
Common stock - 750 shares authorized, no par value, 357 shares issued and outstanding	0	0
Additional paid-in capital	4,479	4,479
Retained earnings	3,145	3,136
Accumulated other comprehensive loss, net	(12)	(12)
Total shareholders' equity	7,653	7,644
Total liabilities and shareholders' equity	$ 21,701	$ 21,728