CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Utility plant:
Utility plant	$ 4,047,282	$ 3,890,423
Less accumulated depreciation and amortization	(1,300,676)	(1,239,865)
Net utility plant	2,746,606	2,650,558
Current assets:
Cash and cash equivalents	66,483	44,555
Receivables:
Customers, net	52,237	44,025
Regulatory balancing accounts	84,585	96,241
Other, net	19,469	20,331
Unbilled revenue, net	52,954	34,069
Materials and supplies at weighted average cost	9,589	8,831
Taxes, prepaid expenses, and other assets	20,269	17,964
Total current assets	305,586	266,016
Other assets:
Regulatory assets	337,132	325,376
Goodwill	36,841	31,842
Other assets	122,588	120,456
Total other assets	496,561	477,674
TOTAL ASSETS	3,548,753	3,394,248
Capitalization:
Common stock, $0.01 par value; 68,000 shares authorized, 51,535 and 50,334 outstanding in 2021 and 2020, respectively	515	503
Additional paid-in capital	512,484	448,632
Retained earnings	484,119	472,209
Noncontrolling interests	5,145	0
Total equity	1,002,263	921,344
Long-term debt, net	1,059,936	781,100
Total capitalization	2,062,199	1,702,444
Current liabilities:
Current maturities of long-term debt, net	5,173	5,127
Short-term borrowings	145,000	370,000
Accounts payable	132,972	131,725
Regulatory balancing accounts	24,839	34,636
Accrued interest	6,853	6,178
Accrued expenses and other liabilities	47,542	41,040
Total current liabilities	362,379	588,706
Deferred income taxes	278,957	276,032
Pension and postretirement benefits other than pensions	112,893	115,581
Regulatory liabilities and other	255,017	247,810
Advances for construction	197,687	195,625
Contributions in aid of construction	279,621	268,050
Commitments and contingencies (Note 10)
TOTAL CAPITALIZATION AND LIABILITIES	$ 3,548,753	$ 3,394,248