Fair Value Measurements (Tables)

9 Months Ended

Sep. 30, 2019

Fair Value Disclosures [Abstract]

Balances Of Assets 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.

	September 30, 2019
(dollars in thousands)	Level 1		Level 2		Level 3		Total
Assets:
Investments:
Fixed maturities, available-for-sale:
U.S. Treasury securities	$	—	$	296,956	$	—	$	296,956
U.S. government-sponsored enterprises	—		359,973		—		359,973
Obligations of states, municipalities and political subdivisions	—		4,320,108		—		4,320,108
Foreign governments	—		1,615,614		—		1,615,614
Commercial mortgage-backed securities	—		1,790,083		—		1,790,083
Residential mortgage-backed securities	—		909,669		—		909,669
Asset-backed securities	—		9,924		—		9,924
Corporate bonds	—		901,698		—		901,698
Total fixed maturities, available-for-sale	—		10,204,025		—		10,204,025
Equity securities:
Insurance, banks and other financial institutions	2,247,952		—		44,489		2,292,441
Industrial, consumer and all other	4,686,433		—		—		4,686,433
Total equity securities	6,934,385		—		44,489		6,978,874
Short-term investments, available-for-sale	1,444,357		101,036		—		1,545,393
Total investments	$	8,378,742	$	10,305,061	$	44,489	$	18,728,292

	December 31, 2018
(dollars in thousands)	Level 1		Level 2		Level 3		Total
Assets:
Investments:
Fixed maturities, available-for-sale:
U.S. Treasury securities	$	—	$	246,642	$	—	$	246,642
U.S. government-sponsored enterprises	—		359,322		—		359,322
Obligations of states, municipalities and political subdivisions	—		4,352,930		—		4,352,930
Foreign governments	—		1,559,604		—		1,559,604
Commercial mortgage-backed securities	—		1,650,199		—		1,650,199
Residential mortgage-backed securities	—		880,172		—		880,172
Asset-backed securities	—		19,408		—		19,408
Corporate bonds	—		974,911		—		974,911
Total fixed maturities, available-for-sale	—		10,043,188		—		10,043,188
Equity securities:
Insurance, banks and other financial institutions	1,876,811		—		53,728		1,930,539
Industrial, consumer and all other	3,790,406		—		—		3,790,406
Total equity securities	5,667,217		—		53,728		5,720,945
Short-term investments, available-for-sale	981,616		96,080		—		1,077,696
Total investments	$	6,648,833	$	10,139,268	$	53,728	$	16,841,829

Summary Of Changes In Level 3 Investments Measured At Fair Value On A Recurring Basis

The following table summarizes changes in Level 3 investments measured at fair value on a recurring basis.

	Quarter Ended September 30,					Nine Months Ended September 30,
(dollars in thousands)	2019			2018		2019			2018
Equity securities, beginning of period	$	37,988		$	119,675	$	53,728		$	168,809
Purchases	—			—		500			28,900
Sales	(857		)	—		(7,726		)	(34,653		)
Net investment gains (losses) on Level 3 investments	7,358			2,418		(2,013		)	(40,963		)
Transfers into Level 3	—			—		—			—
Transfers out of Level 3	—			—		—			—
Equity securities, end of period	$	44,489		$	122,093	$	44,489		$	122,093