Investments in debt and equity securities (Tables)

12 Months Ended

Dec. 31, 2015

Investments, Debt and Equity Securities [Abstract]

Amortized Costs and Fair Values

Amortized costs and fair values at December 31, follow:

	2015		2014
	Amortized costs	Fair values	Amortized costs	Fair values
	($000 omitted)
Debt securities:
Municipal	70,300	72,008	60,656	61,689
Corporate	303,870	309,461	296,578	308,691
Foreign	149,914	153,221	163,099	166,685
U.S. Treasury Bonds	13,803	13,906	14,337	14,802
Equity securities	27,497	31,253	22,710	28,236
	565,384	579,849	557,380	580,103

Gross Unrealized Gains and Losses

Gross unrealized gains and losses at December 31, were:

	2015		2014
	Gains	Losses	Gains	Losses
	($000 omitted)
Debt securities:
Municipal	1,720	12	1,125	92
Corporate	7,700	2,109	12,559	446
Foreign	3,789	482	3,690	104
U.S. Treasury Bonds	128	25	492	27
Equity securities	4,842	1,086	5,982	456
	18,179	3,714	23,848	1,125

Debt Securities According to Contractual Terms

Debt securities at December 31, 2015 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	27,118	27,256
After one year through five years	226,497	230,842
After five years through ten years	230,161	235,219
After ten years	54,111	55,279
	537,887	548,596

Gross Unrealized Losses on Investments and Fair Values of Related Securities

Gross unrealized losses on investments 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, 2014, were:

	Less than 12 months		More than 12 months		Total
	Losses	Fair values	Losses	Fair values	Losses	Fair values
	($000 omitted)
Debt securities:
Municipal	1	2,673	91	12,076	92	14,749
Corporate	107	7,167	339	26,545	446	33,712
Foreign	11	34,236	93	6,446	104	40,682
U.S. Treasury Bonds	—	—	27	3,694	27	3,694
Equity securities:	456	6,540	—	—	456	6,540
	575	50,616	550	48,761	1,125	99,377

Gross unrealized losses on investments 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, 2015, were:

	Less than 12 months		More than 12 months		Total
	Losses	Fair values	Losses	Fair values	Losses	Fair values
	($000 omitted)
Debt securities:
Municipal	9	2,230	3	1,615	12	3,845
Corporate	1,461	83,565	648	32,871	2,109	116,436
Foreign	322	35,008	160	3,155	482	38,163
U.S. Treasury Bonds	6	1,195	19	3,583	25	4,778
Equity securities:	720	4,440	366	3,224	1,086	7,664
	2,518	126,438	1,196	44,448	3,714	170,886