Fair value measurements (Tables)

6 Months Ended

Jun. 30, 2018

Fair Value Disclosures [Abstract]

Financial instruments measured at fair value on recurring basis

As of June 30, 2018, 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	—	62,831	62,831
Corporate	—	342,595	342,595
Foreign	—	219,932	219,932
U.S. Treasury Bonds	—	12,525	12,525
Equity securities	35,450	—	35,450
	35,450	637,883	673,333

As of December 31, 2017, 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	—	72,669	72,669
Corporate	—	357,933	357,933
Foreign	—	228,237	228,237
U.S. Treasury Bonds	—	12,602	12,602
Equity securities	37,914	—	37,914
	37,914	671,441	709,355