Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Assets
Cash and cash equivalents	$ 485,192	$ 679,546
Restricted cash	17,531	15,028
Accounts receivable and unbilled revenues, net	469,298	575,176
Available-for-sale investment securities, at fair value	1,091,889	1,136,439
Held-to-maturity investment securities, at amortized cost	1,191,074	1,201,314
Stock in Federal Home Loan Bank, at cost	32,489	14,728
Loans held for investment, net	6,045,665	6,106,438
Loans held for sale, at lower of cost or fair value	2,923	15,168
Property, plant and equipment, net of accumulated depreciation of $3,374,016 and $3,317,759 at March 31, 2024 and December 31, 2023, respectively	6,183,503	6,150,126
Operating lease right-of-use assets	91,182	94,905
Regulatory assets	315,067	294,804
Other	915,205	877,959
Goodwill	82,190	82,190
Total assets	16,923,208	17,243,821
Liabilities
Accounts payable	248,806	247,462
Interest and dividends payable	61,452	51,206
Deposit liabilities	8,005,064	8,145,778
Other bank borrowings	593,000	750,000
Long-term debt, net—other than bank	2,837,875	2,842,429
Deferred income taxes	299,012	297,954
Operating lease liabilities	99,611	103,900
Finance lease liabilities	350,290	339,040
Regulatory liabilities	1,159,811	1,150,690
Defined benefit pension and other postretirement benefit plans liability	84,554	82,879
Other	772,060	853,349
Total liabilities	14,511,535	14,864,687
Preferred stock of subsidiaries - not subject to mandatory redemption	34,293	34,293
Commitments and contingencies (Notes 2, 4 and 5)
Shareholders’ equity
Preferred stock, no par value, authorized 10,000,000 shares; issued: none	0	0
Common stock, no par value, authorized 200,000,000 shares; issued and outstanding: 110,302,667 shares and 110,151,798 shares at March 31, 2024 and December 31, 2023, respectively	1,707,689	1,707,471
Retained earnings	968,842	926,720
Accumulated other comprehensive loss, net of tax benefits	(299,151)	(289,350)
Total shareholders’ equity	2,377,380	2,344,841
Total liabilities and shareholders’ equity	$ 16,923,208	$ 17,243,821