Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Mar. 31, 2012	Dec. 31, 2011
Utility plant:
Electric plant in service	$ 2,789,419	$ 2,789,773
Less accumulated depreciation and amortization	(1,117,867)	(1,121,653)
Net plant in service	1,671,552	1,668,120
Construction work in progress	189,393	167,394
Nuclear fuel; includes fuel in process of $61,123 and $49,545, respectively	204,793	171,433
Less accumulated amortization	(69,560)	(59,882)
Net nuclear fuel	135,233	111,551
Net utility plant	1,996,178	1,947,065
Current assets:
Cash and cash equivalents	6,114	8,208
Accounts receivable, principally trade, net of allowance for doubtful accounts of $2,712 and $3,015, respectively	64,863	76,348
Accumulated deferred income taxes	17,720	13,752
Inventories, at cost	41,222	40,222
Income taxes receivable	2,214	2,269
Undercollection of fuel revenues	0	9,130
Prepayments and other	6,649	4,810
Total current assets	138,782	154,739
Deferred charges and other assets:
Decommissioning trust funds	178,528	167,963
Regulatory assets	102,421	101,027
Other	30,580	26,057
Total deferred charges and other assets	311,529	295,047
Total assets	2,446,489	2,396,851
Capitalization:
Common stock, stated value $1 per share, 100,000,000 shares authorized, 65,424,153 and 65,295,888 shares issued, and 109,369 and 156,185 restricted shares, respectively	65,534	65,452
Capital in excess of stated value	307,504	309,777
Retained earnings	881,709	887,174
Accumulated other comprehensive income (loss), net of tax	(69,943)	(77,505)
Total stockholders equity subtotal before treasury stock	1,184,804	1,184,898
Treasury stock, 25,492,919 shares at cost	(424,647)	(424,647)
Common stock equity	760,157	760,251
Long-term debt	816,510	816,497
Total capitalization	1,576,667	1,576,748
Current liabilities:
Current maturities of long-term debt	33,300	33,300
Short-term borrowings under the revolving credit facility	92,570	33,379
Accounts payable, principally trade	34,293	51,704
Taxes accrued	23,507	30,700
Interest accrued	13,197	12,123
Overcollection of fuel revenues	4,912	2,105
Other	22,614	21,921
Total current liabilities	224,393	185,232
Deferred credits and other liabilities:
Accumulated deferred income taxes	311,546	299,475
Accrued pension liability	125,170	129,627
Accrued postretirement benefit liability	101,938	100,455
Asset retirement obligation	57,004	56,140
Regulatory liabilities	21,205	21,049
Other	28,566	28,125
Total deferred credits and other liabilities	645,429	634,871
Commitments and contingencies
Total capitalization and liabilities	$ 2,446,489	$ 2,396,851