Fair value measurements (Tables)

6 Months Ended

Jun. 30, 2013

Financial Instruments Measured at Fair Value on Recurring Basis

As of June 30, 2013, financial instruments measured at fair value on a recurring basis are summarized below:

	Level 1		Level 2		Fair value measurements
	($000 omitted)
Short-term investments		36,889		—		36,889
Investments available-for-sale:
Debt securities:
Municipal		—		38,296		38,296
Corporate and utilities		—		276,174		276,174
Foreign		—		160,167		160,167
U.S. Government		—		15,373		15,373
Equity securities		12,580		—		12,580
		49,469		490,010		539,479

As of December 31, 2012, financial instruments measured at fair value on a recurring basis are summarized below:

	Level 1		Level 2		Fair value measurements
	($000 omitted)
Short-term investments		37,025		—		37,025
Investments available-for-sale:
Debt securities:
Municipal		—		19,011		19,011
Corporate and utilities		—		287,528		287,528
Foreign		—		169,009		169,009
U.S. Government		—		16,638		16,638
Equity securities		11,073		—		11,073
		48,098		492,186		540,284