CONSOLIDATED BALANCE SHEETS (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Utility plant:
Electric plant in service	$ 2,789,773	$ 2,522,862
Less accumulated depreciation and amortization	(1,121,653)	(1,047,498)
Net plant in service	1,668,120	1,475,364
Construction work in progress	167,394	285,086
Nuclear fuel; includes fuel in process of $49,545 and $47,746, respectively	171,433	150,774
Less accumulated amortization	(59,882)	(45,471)
Net nuclear fuel	111,551	105,303
Net utility plant	1,947,065	1,865,753
Current assets:
Cash and cash equivalents	8,208	79,184
Accounts receivable, principally trade, net of allowance for doubtful accounts of $3,015 and $2,885, respectively	76,348	71,685
Accumulated deferred income taxes	13,752	25,818
Inventories, at cost	40,222	36,132
Income taxes receivable	2,269	12,656
Undercollection of fuel revenues	9,130	0
Prepayments and other	4,810	4,543
Total current assets	154,739	230,018
Deferred charges and other assets:
Decommissioning trust funds	167,963	153,878
Regulatory assets	101,027	88,557
Other	26,057	26,560
Total deferred charges and other assets	295,047	268,995
Total assets	2,396,851	2,364,766
Capitalization:
Common stock, stated value $1 per share, 100,000,000 shares authorized, 65,295,888 and 65,121,689 shares issued, and 156,185 and 143,371 restricted shares, respectively	65,452	65,265
Capital in excess of stated value	309,777	305,068
Retained earnings	887,174	810,858
Accumulated other comprehensive income (loss), net of tax	(77,505)	(33,177)
Stockholders Equity Subtotal Before Treasury Stock	1,184,898	1,148,014
Treasury stock, 25,492,919 and 22,693,995 shares, respectively, at cost	(424,647)	(337,639)
Common stock equity	760,251	810,375
Long-term debt	816,497	849,745
Total capitalization	1,576,748	1,660,120
Current liabilities:
Current maturities of long-term debt	33,300	0
Short-term borrowings under the revolving credit facility	33,379	4,704
Accounts payable, principally trade	51,704	41,795
Taxes accrued	30,700	29,172
Interest accrued	12,123	12,099
Overcollection of fuel revenues	2,105	18,976
Other	21,921	24,207
Total current liabilities	185,232	130,953
Deferred credits and other liabilities:
Accumulated deferred income taxes	299,475	286,730
Accrued pension liability	129,627	93,471
Accrued postretirement benefit liability	100,455	61,594
Asset retirement obligation	56,140	92,911
Regulatory liabilities	21,049	14,489
Other	28,125	24,498
Total deferred credits and other liabilities	634,871	573,693
Commitments and contingencies
Total capitalization and liabilities	$ 2,396,851	$ 2,364,766