Fair value measurements (Tables)

3 Months Ended

Mar. 31, 2013

Financial Instruments Measured at Fair Value on Recurring Basis

As of March 31, 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		36,146		—		36,146
Investments available-for-sale:
Debt securities:
Municipal		—		38,625		38,625
Corporate and utilities		—		287,484		287,484
Foreign		—		168,166		168,166
U.S. Government		—		15,622		15,622
Equity securities		12,153		—		12,153
		48,299		509,897		558,196

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