Investment Securities

9 Months Ended

Sep. 30, 2023

Investments, Debt and Equity Securities [Abstract]

Investment Securities

Investment Securities.    Investment securities we hold are recorded at fair value in the accompanying consolidated balance sheets. We apply regulated operations accounting to the unrealized gains and losses of all investment securities. All realized and unrealized gains and losses are determined using the specific identification method.

The following tables summarize debt and equity securities as of September 30, 2023 and December 31, 2022.

	Gross Unrealized
	(dollars in thousands)
September 30, 2023	Cost		Gains		Losses		Fair Value
Equity	$	336,686	$	188,411	$	(7,128)	$	517,969
Debt	888,899		686		(46,470)		843,115
Other	7,040		29		(21)		7,048
Total	$	1,232,625	$	189,126	$	(53,619)	$	1,368,132

	Gross Unrealized
	(dollars in thousands)
December 31, 2022	Cost		Gains		Losses		Fair Value
Equity	$	323,907	$	159,445	$	(8,949)	$	474,403
Debt	833,035		372		(46,369)		787,038
Other	10,445		20		(9)		10,456
Total	$	1,167,387	$	159,837	$	(55,327)	$	1,271,897