Unaudited Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
CURRENT ASSETS:
Cash and cash equivalents	$ 20,629	$ 20,502
Restricted Cash and Cash Equivalents	5	6,120
Accounts Receivable, after Allowance for Credit Loss, Current	158,962	165,193
Inventory, Net	81,460	95,506
Regulatory assets	62,188	45,430
Income Taxes Receivable, Current	20,709	24,384
Other Assets, Current	30,369	17,842
Total current assets	374,322	374,977
UTILITY PLANT:
Property, Plant and Equipment, Gross	6,479,619	6,530,395
Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment	2,594,590	2,643,695
Utility plant in service - net	3,885,029	3,886,700
Construction in Progress, Gross	246,871	209,584
Total net property, plant and equipment	4,131,900	4,096,284
OTHER ASSETS:
Intangible Assets, Net (Excluding Goodwill)	56,765	59,141
Regulatory assets	372,339	392,801
Other assets - net	58,879	46,716
Assets, Noncurrent	487,983	498,658
TOTAL ASSETS	4,994,205	4,969,919
Debt, Current	100,000	169,907
CURRENT LIABILITIES:
Accounts payable	151,511	127,089
Accrued taxes	26,404	26,620
Interest Payable, Current	31,785	31,733
Customer deposits	27,747	27,929
Regulatory Liability, Current	12,503	30,036
Accrued Liabilities and Other Liabilities	15,606	19,453
Total current liabilities	365,556	432,767
NON-CURRENT LIABILITIES:
Long-term debt (Note 4)	2,652,396	2,556,278
Deferred income tax liabilities	291,517	275,714
Taxes Payable	7,552	7,458
Regulatory Liability, Noncurrent	830,788	839,360
Accrued pension and other postretirement benefits	5,426	5,334
Asset retirement obligations	194,926	195,236
Other non-current liabilities	13,565	13,785
Total non-current liabilities	4,042,185	3,956,380
Liabilities	4,407,741	4,389,147
Common shareholders' equity:
Additional Paid in Capital	580,831	588,966
Accumulated Other Comprehensive Income (Loss), Net of Tax	(29,593)	(43,420)
Accumulated deficit	(24,558)	(24,558)
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	526,680	520,988
Cumulative preferred stock of subsidiary	59,784	59,784
Total common shareholders' equity	586,464	580,772
TOTAL LIABILITIES AND SHAREHOLDERS' EQUITY	4,994,205	4,969,919
Derivative Liability, Noncurrent	46,015	63,215
Accounts Receivable, Allowance for Credit Loss, Current	1,553	3,155
Accounts receivable and unbilled revenue, allowance for doubtful accounts	$ 1,553	$ 3,155