Investments (Tables)

3 Months Ended

Mar. 31, 2021

Investments [Abstract]

Summary Of Unrealized Appreciation (Depreciation) Of Available For Sale, Fixed Maturity And Equity Security Investments

	At March 31, 2021
	Amortized		Allowances for		Unrealized		Unrealized		Market
(Dollars in thousands)	Cost		Credit Losses		Appreciation		Depreciation		Value
Fixed maturity securities
U.S. Treasury securities and obligations of U.S. government agencies and corporations	$	622,352	$	-	$	16,658	$	(167)	$	638,843
Obligations of U.S. states and political  subdivisions		565,697		-		32,092		(2,741)		595,048
Corporate securities		3,660,209		(3,588)		114,692		(41,884)		3,729,429
Asset-backed securities		2,471,769		(4,915)		25,459		(2,210)		2,490,103
Mortgage-backed securities
Commercial		554,472		-		23,276		(5,158)		572,590
Agency residential		989,178		-		24,826		(8,153)		1,005,851
Non-agency residential		6,262		-		4		(2)		6,264
Foreign government securities		734,630		-		38,724		(4,065)		769,289
Foreign corporate securities		1,194,944		(205)		55,057		(7,212)		1,242,584
Total fixed maturity securities	$	10,799,513	$	(8,708)	$	330,788	$	(71,592)	$	11,050,001

	At December 31, 2020
	Amortized		Allowances for		Unrealized		Unrealized		Market
(Dollars in thousands)	Cost		Credit Losses		Appreciation		Depreciation		Value
Fixed maturity securities
U.S. Treasury securities and obligations of U.S. government agencies and corporations	$	659,957	$	-	$	22,032	$	-	$	681,989
Obligations of U.S. states and political  subdivisions		543,646		-		34,655		(1,255)		577,046
Corporate securities		3,316,525		(1,205)		166,072		(31,480)		3,449,912
Asset-backed securities		2,450,807		-		28,585		(5,222)		2,474,170
Mortgage-backed securities
Commercial		512,388		-		37,875		(183)		550,080
Agency residential		937,166		-		28,630		(696)		965,100
Non-agency residential		3,164		-		2		(2)		3,164
Foreign government securities		694,132		-		51,317		(3,211)		742,238
Foreign corporate securities		1,130,865		(361)		73,265		(3,903)		1,199,866
Total fixed maturity securities	$	10,248,650	$	(1,566)	$	442,433	$	(45,952)	$	10,643,565

Summary Of Amortized Cost And Market Value Of Fixed Maturity Securities, By Contractual Maturity

	At March 31, 2021				At December 31, 2020
	Amortized		Market		Amortized		Market
(Dollars in thousands)	Cost		Value		Cost		Value
Fixed maturity securities – available for sale
Due in one year or less	$	710,217	$	715,721	$	658,561	$	659,622
Due after one year through five years		2,970,305		3,077,551		2,911,285		3,036,151
Due after five years through ten years		2,348,514		2,421,105		1,927,265		2,079,866
Due after ten years		748,796		760,816		848,014		875,412
Asset-backed securities		2,471,769		2,490,103		2,450,807		2,474,170
Mortgage-backed securities
Commercial		554,472		572,590		512,388		550,080
Agency residential		989,178		1,005,851		937,166		965,100
Non-agency residential		6,262		6,264		3,164		3,164
Total fixed maturity securities	$	10,799,513	$	11,050,001	$	10,248,650	$	10,643,565

Summary Of Changes In Net Unrealized Appreciation (Depreciation) For The Company's Investments

	Three Months Ended
	March 31,
(Dollars in thousands)	2021		2020
Increase (decrease) during the period between the market value and cost of investments carried at market value, and deferred taxes thereon:
Fixed maturity securities	$	(137,150)	$	(188,407)
Change in unrealized appreciation (depreciation), pre-tax		(137,150)		(188,407)
Deferred tax benefit (expense)		28,782		38,769
Change in unrealized appreciation (depreciation),  net of deferred taxes, included in stockholder's equity	$	(108,368)	$	(149,638)

Summary Of Aggregate Market Value And Gross Unrealized Depreciation Of Fixed Maturity And Equity Securities, By Security Type

	Duration of Unrealized Loss at March 31, 2021 By Security Type
	Less than 12 months				Greater than 12 months				Total
			Gross				Gross				Gross
	Market		Unrealized		Market		Unrealized		Market		Unrealized
(Dollars in thousands)	Value		Depreciation		Value		Depreciation		Value		Depreciation
Fixed maturity securities -  available for sale
U.S. Treasury securities and  obligations of U.S. government  agencies and corporations	$	38,242	$	(167)	$	-	$	-	$	38,242	$	(167)
Obligations of U.S. states and  political subdivisions		56,822		(1,710)		12,079		(1,031)		68,901		(2,741)
Corporate securities		790,015		(24,012)		187,655		(17,872)		977,670		(41,884)
Asset-backed securities		240,987		(1,749)		22,773		(461)		263,760		(2,210)
Mortgage-backed securities
Commercial		120,334		(5,158)		-		-		120,334		(5,158)
Agency residential		529,830		(8,000)		12,012		(153)		541,842		(8,153)
Non-agency residential		3,529		-		156		(2)		3,685		(2)
Foreign government securities		69,597		(1,550)		22,968		(2,515)		92,565		(4,065)
Foreign corporate securities		248,667		(5,705)		14,374		(1,507)		263,041		(7,212)
Total fixed maturity securities	$	2,098,023	$	(48,051)	$	272,017	$	(23,541)	$	2,370,040	$	(71,592)

	Duration of Unrealized Loss at December 31, 2020 By Security Type
	Less than 12 months				Greater than 12 months				Total
			Gross				Gross				Gross
	Market		Unrealized		Market		Unrealized		Market		Unrealized
(Dollars in thousands)	Value		Depreciation		Value		Depreciation		Value		Depreciation
Fixed maturity securities -  available for sale
Obligations of U.S. states and  political subdivisions		19,524		(999)		4,059		(256)		23,583		(1,255)
Corporate securities		240,601		(7,799)		188,853		(23,681)		429,454		(31,480)
Asset-backed securities		223,919		(4,573)		81,952		(649)		305,871		(5,222)
Mortgage-backed securities
Commercial		37,414		(182)		3,983		(1)		41,397		(183)
Agency residential		235,809		(682)		1,573		(14)		237,382		(696)
Non-agency residential		161		(2)		-		-		161		(2)
Foreign government securities		10,505		(373)		25,793		(2,838)		36,298		(3,211)
Foreign corporate securities		57,900		(2,182)		18,349		(1,721)		76,249		(3,903)
Total fixed maturity securities	$	825,833	$	(16,792)	$	324,562	$	(29,160)	$	1,150,395	$	(45,952)

Summary Of Aggregate Market Value And Gross Unrealized Depreciation Of Fixed Maturity And Equity Securities, By Contractual Maturity

	Duration of Unrealized Loss at March 31, 2021 By Maturity
	Less than 12 months				Greater than 12 months				Total
			Gross				Gross				Gross
	Market		Unrealized		Market		Unrealized		Market		Unrealized
(Dollars in thousands)	Value		Depreciation		Value		Depreciation		Value		Depreciation
Fixed maturity securities
Due in one year or less	$	45,431	$	(823)	$	27,415	$	(3,064)	$	72,846	$	(3,887)
Due in one year through five years		434,857		(7,796)		112,809		(3,662)		547,666		(11,458)
Due in five years through ten years		544,227		(18,240)		9,671		(658)		553,898		(18,898)
Due after ten years		178,828		(6,285)		87,181		(15,541)		266,009		(21,826)
Asset-backed securities		240,987		(1,749)		22,773		(461)		263,760		(2,210)
Mortgage-backed securities		653,693		(13,158)		12,168		(155)		665,861		(13,313)
Total fixed maturity securities	$	2,098,023	$	(48,051)	$	272,017	$	(23,541)	$	2,370,040	$	(71,592)

	Duration of Unrealized Loss at December 31, 2020 By Maturity
	Less than 12 months				Greater than 12 months				Total
			Gross				Gross				Gross
	Market		Unrealized		Market		Unrealized		Market		Unrealized
(Dollars in thousands)	Value		Depreciation		Value		Depreciation		Value		Depreciation
Fixed maturity securities
Due in one year or less	$	28,802	$	(1,218)	$	34,555	$	(4,142)	$	63,357	$	(5,360)
Due in one year through five years		150,106		(5,828)		116,987		(4,783)		267,093		(10,611)
Due in five years through ten years		81,492		(1,634)		13,118		(435)		94,610		(2,069)
Due after ten years		68,130		(2,673)		72,394		(19,136)		140,524		(21,809)
Asset-backed securities		223,919		(4,573)		81,952		(649)		305,871		(5,222)
Mortgage-backed securities		273,384		(866)		5,556		(15)		278,940		(881)
Total fixed maturity securities	$	825,833	$	(16,792)	$	324,562	$	(29,160)	$	1,150,395	$	(45,952)

Summary Of Components Of Net Investment Income

	Three Months Ended
	March 31,
(Dollars in thousands)	2021		2020
Fixed maturities	$	85,121	$	74,088
Equity securities		2,923		1,592
Short-term investments and cash		153		1,570
Other invested assets
Limited partnerships		52,151		6,996
Dividends from preferred shares of affiliate		7,758		7,758
Other		6,019		(13,072)
Gross investment income before adjustments		154,125		78,932
Funds held interest income (expense)		3,489		3,257
Interest income from Parent		1,268		1,282
Gross investment income		158,882		83,471
Investment expenses		(11,159)		(9,270)
Net investment income	$	147,723	$	74,201
(Some amounts may not reconcile due to rounding.)

Summary Of Components Of Net Realized Capital Gains (Losses)

	Three Months Ended
	March 31,
(Dollars in thousands)	2021		2020
Fixed maturity securities, market value:
Allowances for credit losses	$	(7,142)	$	(12,099)
Gains (losses) from sales		3,927		(20,937)
Fixed maturity securities, fair value:
Gains (losses) from fair value adjustments		-		(1,123)
Equity securities, fair value:
Gains (losses) from sales		6,238		(27,602)
Gains (losses) from fair value adjustments		37,551		(121,669)
Other invested assets		1,346		(2,327)
Other invested assets, fair value:
Gains (losses) from fair value adjustments		93,078		442,479
Short-term investment gains (losses)		13		145
Total net realized capital gains (losses)	$	135,011	$	256,867

	Roll Forward of Allowance for Credit Losses
	Three Months Ended March 31, 2021								Three Months Ended March 31, 2020
			Asset		Foreign						Asset		Foreign
	Corporate		Backed		Corporate				Corporate		Backed		Corporate
	Securities		Securities		Securities		Total		Securities		Securities		Securities		Total
Beginning Balance	$	(1,205)	$	-	$	(361)	$	(1,566)	$	-	$	-	$	-	$	-
Credit losses on securities where credit
losses were not previously recorded		(2,383)		(4,915)		-		(7,298)		(11,468)		(70)		(561)		(12,099)
Increases in allowance on previously
impaired securities		-		-		-		-		-		-		-		-
Decreases in allowance on previously
impaired securities		-		-		-		-		-		-		-		-
Reduction in allowance due to disposals		-		-		156		156		-		-		-		-
Balance as of March 31	$	(3,588)	$	(4,915)	$	(205)	$	(8,708)	$	(11,468)	$	(70)	$	(561)	$	(12,099)

Summary Of Gross Gains (Losses) From Sales Of Fixed Maturity And Equity Securities

	Three Months Ended
	March 31,
(Dollars in thousands)	2021		2020
Proceeds from sales of fixed maturity securities	$	492,943	$	164,244
Gross gains from sales		6,349		1,846
Gross losses from sales		(2,422)		(22,783)
Proceeds from sales of equity securities	$	281,313	$	204,161
Gross gains from sales		12,304		2,581
Gross losses from sales		(6,066)		(30,183)