Consolidated Balance Sheets (Current Period Not Audited) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Current Assets
Cash and Cash Equivalents	$ 1,036	$ 16,216
Accounts Receivable:
Trade—Net	91,780	68,466
Other	10,224	7,761
Inventories	90,435	88,034
Unbilled Receivables	18,278	22,427
Income Taxes Receivable		1,181
Regulatory Assets	17,914	22,551
Other	9,574	12,491
Total Current Assets	239,241	239,127
Investments	8,649	8,629
Other Assets	36,519	36,006
Goodwill	37,572	37,572
Other Intangibles—Net	13,075	13,765
Regulatory Assets	123,631	129,576
Plant
Electric Plant in Service	1,993,738	1,981,018
Nonelectric Operations	223,323	216,937
Construction Work in Progress	168,372	141,067
Total Gross Plant	2,385,433	2,339,022
Less Accumulated Depreciation and Amortization	832,873	799,419
Net Plant	1,552,560	1,539,603
Total Assets	2,011,247	2,004,278
Current Liabilities
Short-Term Debt	20,977	112,371
Current Maturities of Long-Term Debt	167	186
Accounts Payable	95,082	84,185
Accrued Salaries and Wages	18,460	21,534
Accrued Federal and State Income Taxes	673
Other Accrued Taxes	10,963	16,808
Regulatory Liabilities	7,248	9,688
Other Accrued Liabilities	12,665	11,389
Liabilities of Discontinued Operations		492
Total Current Liabilities	166,235	256,653
Pensions Benefit Liability	89,424	109,708
Other Postretirement Benefits Liability	70,203	69,774
Other Noncurrent Liabilities	25,060	22,769
Commitments and Contingencies (note 8)
Deferred Credits
Deferred Income Taxes	104,382	100,501
Deferred Tax Credits	20,676	21,379
Regulatory Liabilities - Long -Term	228,163	232,893
Other	2,563	3,329
Total Deferred Credits	355,784	358,102
Capitalization
Long-Term Debt—Net	589,960	490,380
Common Shares, Par Value $5 Per Share—Authorized, 50,000,000 Shares; Outstanding, 2018—39,651,436 Shares; 2017—39,557,491 Shares	198,257	197,787
Premium on Common Shares	342,690	343,450
Retained Earnings	179,605	161,286
Accumulated Other Comprehensive Loss	(5,971)	(5,631)
Total Common Equity	714,581	696,892
Total Capitalization	1,304,541	1,187,272
Total Liabilities and Equity	2,011,247	2,004,278
Cumulative Preferred Shares [Member]
Capitalization
Cumulative Shares
Cumulative Preference Shares [Member]
Capitalization
Cumulative Shares