Fair value measurements (Tables)

3 Months Ended

Mar. 31, 2024

Fair Value Disclosures [Abstract]

Schedule of Financial Instruments Measured at Fair Value on Recurring Basis

As of March 31, 2024, financial instruments measured at fair value on a recurring basis are summarized below:

	Level 1	Level 2	Fair value measurements
	($000 omitted)
Investments in securities:
Debt securities:
Municipal	—	18,499	18,499
Corporate	—	228,668	228,668
Foreign	—	315,661	315,661
U.S. Treasury Bonds	—	34,229	34,229
Equity securities	76,893	—	76,893
	76,893	597,057	673,950

As of December 31, 2023, financial instruments measured at fair value on a recurring basis are summarized below:

	Level 1	Level 2	Fair value measurements
	($000 omitted)
Investments in securities:
Debt securities:
Municipal	—	22,031	22,031
Corporate	—	231,474	231,474
Foreign	—	323,391	323,391
U.S. Treasury Bonds	—	33,340	33,340
Equity securities	69,700	—	69,700
	69,700	610,236	679,936