Investments in debt and equity securities (Tables)

3 Months Ended

Mar. 31, 2024

Investments, Debt and Equity Securities [Abstract]

Schedule of Amortized Costs and Fair Values

The amortized costs and fair values of investments in debt securities are as follows:

	March 31, 2024		December 31, 2023
	Amortized costs	Fair values	Amortized costs	Fair values
	($000 omitted)
Municipal	18,725	18,499	22,201	22,031
Corporate	240,573	228,668	242,656	231,474
Foreign	326,560	315,661	332,723	323,391
U.S. Treasury Bonds	34,948	34,229	33,714	33,340
	620,806	597,057	631,294	610,236

Proceeds from sales of investments in securities are as follows: 

		Three Months Ended   March 31,
		2024	2023
	($000 omitted)
Proceeds from sales of debt securities		20,767	7,446
Proceeds from sales of equity securities		107	19,326
Total proceeds from sales of investments in securities		20,874	26,772

Schedule of Gross Unrealized Gains and Losses

Gross unrealized gains and losses on investments in debt securities are as follows:

	March 31, 2024		December 31, 2023
	Gains	Losses	Gains	Losses
	($000 omitted)
Municipal	2	228	—	170
Corporate	515	12,420	764	11,946
Foreign	858	11,757	1,765	11,097
U.S. Treasury Bonds	25	744	106	480
	1,400	25,149	2,635	23,693

Schedule of Debt Securities According to Contractual Terms

Debt securities as of March 31, 2024 mature, according to their contractual terms, as follows (actual maturities may differ due to call or prepayment rights):

	Amortized costs	Fair values
	($000 omitted)
In one year or less	85,105	84,346
After one year through five years	341,785	327,413
After five years through ten years	177,015	169,663
After ten years	16,901	15,635
	620,806	597,057

Schedule of Gross Unrealized Losses on Investments and Fair Values of Related Securities

Gross unrealized losses on investments in debt securities and the fair values of the related securities, aggregated by investment category and length of time that individual securities have been in a continuous unrealized loss position at March 31, 2024, were:

	Less than 12 months		More than 12 months		Total
	Losses	Fair values	Losses	Fair values	Losses	Fair values
	($000 omitted)
Municipal	46	5,628	182	10,619	228	16,247
Corporate	118	14,737	12,302	196,546	12,420	211,283
Foreign	1,079	66,628	10,678	206,074	11,757	272,702
U.S. Treasury Bonds	553	26,207	191	4,886	744	31,093
	1,796	113,200	23,353	418,125	25,149	531,325

Gross unrealized losses on investments in debt securities and the fair values of the related securities, aggregated by investment category and length of time that individual securities have been in a continuous unrealized loss position at December 31, 2023, were:

	Less than 12 months		More than 12 months		Total
	Losses	Fair values	Losses	Fair values	Losses	Fair values
	($000 omitted)
Municipal	50	13,022	120	8,383	170	21,405
Corporate	68	4,808	11,878	208,971	11,946	213,779
Foreign	472	31,918	10,625	216,135	11,097	248,053
U.S. Treasury Bonds	327	20,895	153	4,815	480	25,710
	917	70,643	22,776	438,304	23,693	508,947