Investments in debt and equity securities (Tables)

12 Months Ended

Dec. 31, 2012

Amortized Costs and Fair Values

The amortized costs and fair values at December 31 follow:

	2012				2011
	Amortized costs		Fair values		Amortized costs		Fair values
	($000 omitted)
Debt securities:
Municipal		18,012		19,011		26,721		27,801
Corporate and utilities		268,874		287,528		237,912		244,123
Foreign		168,084		169,009		162,384		164,268
U.S. Government		15,243		16,638		17,530		19,350
Equity securities		10,870		11,073		5,005		5,443
		481,083		503,259		449,552		460,985

Gross Unrealized Gains and Losses

Gross unrealized gains and losses at December 31 were:

	2012				2011
	Gains		Losses		Gains		Losses
	($000 omitted)
Debt securities:
Municipal		1,006		7		1,080		—
Corporate and utilities		19,141		486		9,184		2,973
Foreign		1,210		286		1,937		53
U.S. Government		1,395		—		1,820		—
Equity securities		278		75		442		4
		23,030		854		14,463		3,030

Debt Securities According to Contractual Terms

Debt securities at December 31, 2012 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		17,673		17,905
After one year through five years		211,288		217,187
After five years through ten years		208,966		222,499
After ten years		32,286		34,595
		470,213		492,186

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, 2012, were:

	Less than 12 months				More than 12 months				Total
	Losses		Fair values		Losses		Fair values		Losses		Fair values
	($000 omitted)
Debt securities:
Municipal		7		697		—		—		7		697
Corporate and utilities		486		30,538		—		—		486		30,538
Foreign		168		41,056		118		59,538		286		100,594
Equity securities:		75		2,197		—		—		75		2,197
		736		74,488		118		59,538		854		134,026

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, 2011, were:

	Less than 12 months				More than 12 months				Total
	Losses		Fair values		Losses		Fair values		Losses		Fair values
	($000 omitted)
Debt securities:
Corporate and utilities		1,944		42,851		1,029		24,830		2,973		67,681
Foreign		53		59,708		—		—		53		59,708
Equity securities:		4		1,247		—		—		4		1,247
		2,001		103,806		1,029		24,830		3,030		128,636