Fair value measurements (Tables)

3 Months Ended

Mar. 31, 2015

Fair Value Disclosures [Abstract]

Financial Instruments Measured at Fair Value on Recurring Basis

As of March 31, 2015, financial instruments measured at fair value on a recurring basis are summarized below:

	Level 1	Level 2	Fair value measurements
	($000 omitted)
Investments available-for-sale:
Debt securities:
Municipal	—	62,807	62,807
Corporate	—	309,556	309,556
Foreign	—	158,769	158,769
U.S. Treasury Bonds	—	14,228	14,228
Equity securities	27,216	—	27,216
	27,216	545,360	572,576

As of December 31, 2014, financial instruments measured at fair value on a recurring basis are summarized below:

	Level 1	Level 2	Fair value measurements
	($000 omitted)
Investments available-for-sale:
Debt securities:
Municipal	—	61,689	61,689
Corporate	—	308,691	308,691
Foreign	—	166,685	166,685
U.S. Treasury Bonds	—	14,802	14,802
Equity securities	28,236	—	28,236
	28,236	551,867	580,103