Fair Value Measurements (Tables)

12 Months Ended

Dec. 31, 2015

Fair Value Disclosures [Abstract]

Balances Of Assets And Liabilities Measured At Fair Value On A Recurring Basis

The following tables present the balances of assets measured at fair value on a recurring basis by level within the fair value hierarchy.

	December 31, 2015
(dollars in thousands)	Level 1		Level 2		Level 3		Total
Assets:
Investments available-for-sale:
Fixed maturities:
U.S. Treasury securities and obligations of U.S. government agencies	$	—	$	700,707	$	—	$	700,707
Obligations of states, municipalities and political subdivisions	—		4,013,213		—		4,013,213
Foreign governments	—		1,416,457		—		1,416,457
Commercial mortgage-backed securities	—		659,538		—		659,538
Residential mortgage-backed securities	—		854,247		—		854,247
Asset-backed securities	—		36,071		—		36,071
Corporate bonds	—		1,714,235		—		1,714,235
Total fixed maturities	—		9,394,468		—		9,394,468
Equity securities:
Insurance, banks and other financial institutions	1,334,722		—		—		1,334,722
Industrial, consumer and all other	2,739,753		—		—		2,739,753
Total equity securities	4,074,475		—		—		4,074,475
Short-term investments	1,529,924		112,337		—		1,642,261
Total investments available-for-sale	$	5,604,399	$	9,506,805	$	—	$	15,111,204

	December 31, 2014
(dollars in thousands)	Level 1		Level 2		Level 3		Total
Assets:
Investments available-for-sale:
Fixed maturities:
U.S. Treasury securities and obligations of U.S. government agencies	$	—	$	673,262	$	—	$	673,262
Obligations of states, municipalities and political subdivisions	—		4,317,547		—		4,317,547
Foreign governments	—		1,611,921		—		1,611,921
Commercial mortgage-backed securities	—		430,627		—		430,627
Residential mortgage-backed securities	—		982,847		—		982,847
Asset-backed securities	—		99,490		—		99,490
Corporate bonds	—		2,307,188		—		2,307,188
Total fixed maturities	—		10,422,882		—		10,422,882
Equity securities:
Insurance, banks and other financial institutions	1,311,925		—		—		1,311,925
Industrial, consumer and all other	2,825,651		—		—		2,825,651
Total equity securities	4,137,576		—		—		4,137,576
Short-term investments	1,469,975		124,874		—		1,594,849
Total investments available-for-sale	$	5,607,551	$	10,547,756	$	—	$	16,155,307