Fair Value Measurements (Tables)

3 Months Ended

Mar. 31, 2021

Fair Value Disclosures [Abstract]

Assets And Liabilities Measured At Fair value, On A Recurring Basis

The following tables present the assets and liabilities measured at fair value on a recurring basis as of March 31, 2021 and December 31, 2020 by level:

(In thousands)	Total		Level 1		Level 2		Level 3
March 31, 2021
Assets:
Fixed maturity securities available for sale:
U.S. government and government agency	$	555,714	$	—	$	555,714	$	—
State and municipal	3,502,593		—		3,502,593		—
Mortgage-backed securities	1,076,024		—		1,076,024		—
Asset-backed securities	3,944,638		—		3,944,638		—
Corporate	5,218,189		—		5,218,189		—
Foreign government	1,029,879		—		1,029,879		—
Total fixed maturity securities available for sale	15,327,037		—		15,327,037		—
Equity securities:
Common stocks	392,163		382,822		—		9,341
Preferred stocks	229,466		—		220,135		9,331
Total equity securities	621,629		382,822		220,135		18,672
Arbitrage trading account	614,721		498,401		116,320		—
Total	$	16,563,387	$	881,223	$	15,663,492	$	18,672
Liabilities:
Trading account securities sold but not yet purchased	$	218	$	218	$	—	$	—
December 31, 2020
Assets:
Fixed maturity securities available for sale:
U.S. government and government agency	$	603,871	$	—	$	603,871	$	—
State and municipal	3,620,664		—		3,620,664		—
Mortgage-backed securities	1,020,330		—		1,020,330		—
Asset-backed securities	3,194,586		—		3,194,586		—
Corporate	4,671,581		—		4,670,581		1,000
Foreign government	975,563		—		975,563		—
Total fixed maturity securities available for sale	14,086,595		—		14,085,595		1,000
Equity securities:
Common stocks	350,181		340,966		—		9,215
Preferred stocks	275,486		—		266,155		9,331
Total equity securities	625,667		340,966		266,155		18,546
Arbitrage trading account	341,473		298,359		43,114		—
Total	$	15,053,735	$	639,325	$	14,394,864	$	19,546
Liabilities:
Trading account securities sold but not yet purchased	$	10,048	$	10,048	$	—	$	—

Summarize Changes In Level 3 Assets

The following tables summarize changes in Level 3 assets and liabilities for the three months ended March 31, 2021 and for the year ended December 31, 2020:

	Gains (Losses) Included in:
(In thousands)	Beginning Balance		Earnings (Losses)		Other Comprehensive Income		Impairments		Purchases		(Sales)		Paydowns / Maturities		Transfers In / (Out)		Ending Balance
Three Months Ended March 31, 2021
Assets:
Fixed maturities securities available for sale:
Corporate	$	1,000	$	—	$	—	$	—	$	—	$	(1,000)	$	—	$	—	$	—
Total	1,000		—		—		—		—		(1,000)		—		—		—
Equity securities:
Common stocks	$	9,215	$	126	$	—	$	—	$	—	$	—	$	—	$	—	$	9,341
Preferred stocks	9,331		—		—		—		—		—		—		—		9,331
Total	18,546		126		—		—		—		—		—		—		18,672
Arbitrage trading account	—		1		—		—		—		(1)		—		—		—
Total	$	19,546	$	127	$	—	$	—	$	—	$	(1,001)	$	—	$	—	$	18,672
Year Ended December 31, 2020
Assets:
Fixed maturities securities available for sale:
Corporate	$	—	$	—	$	—	$	—	$	—	$	—	$	—	$	1,000	$	1,000
Total	—		—		—		—		—		—		—		1,000		1,000
Equity securities:
Common stocks	9,053		1,228		—		—		—		(1,066)		—		—		9,215
Preferred stocks	6,505		(174)		—		—		3,000		—		—		—		9,331
Total	15,558		1,054		—		—		3,000		(1,066)		—		—		18,546
Arbitrage trading account	—		19		—		—		—		(19)		—		—		—
Total	$	15,558	$	1,073	$	—	$	—	$	3,000	$	(1,085)	$	—	$	1,000	$	19,546