Fair value measurements (Tables)

6 Months Ended

Jun. 30, 2014

Fair Value Disclosures [Abstract]

Financial Instruments Measured at Fair Value on Recurring Basis

As of June 30, 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	—	52,137	52,137
Corporate	—	305,035	305,035
Foreign	—	174,350	174,350
U.S. Treasury Bonds	—	15,042	15,042
Equity securities	22,479	—	22,479
	22,479	546,564	569,043

As of December 31, 2013, 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	—	47,252	47,252
Corporate	—	291,832	291,832
Foreign	—	162,367	162,367
U.S. Government	—	15,197	15,197
Equity securities	20,695	—	20,695
	20,695	516,648	537,343