Investments (Tables)

9 Months Ended

Sep. 30, 2020

Investments Debt And Equity Securities [Abstract]

Schedule of Disposition of Fixed Maturities and Equities

Sales	Proceeds		Gross Realized					Net Realized
(in thousands)	From Sales		Gains		Losses			Gain (Loss)
2020
Available-for-sale	$	68,621	$	4,959	$	(1,518	)	$	3,441
Equities		66,185		22,172		(8,756	)		13,416
2019
Available-for-sale	$	174,767	$	3,689	$	(1,393	)	$	2,296
Equities		48,650		15,575		(1,184	)		14,391

Calls/Maturities			Gross Realized					Net Realized
(in thousands)	Proceeds		Gains		Losses			Gain (Loss)
2020
Available-for-sale	$	199,036	$	525	$	(10	)	$	515
2019
Available-for-sale	$	106,241	$	133	$	(14	)	$	119

Fair Value, Assets Measured on Recurring Basis

	As of September 30, 2020
	Fair Value Measurements Using
		Quoted Prices in		Significant Other		Significant
		Active Markets for		Observable		Unobservable
		Identical Assets		Inputs		Inputs
(in thousands)		(Level 1)		(Level 2)		(Level 3)		Total
Fixed income securities - available-for-sale
U.S. government		$	—	$	190,204	$	—	$	190,204
U.S. agency			—		33,180		—		33,180
Non-U.S. govt. & agency			—		10,831		—		10,831
Agency MBS			—		396,852		—		396,852
ABS/CMBS*			—		208,282		—		208,282
Corporate			—		793,012		11,925		804,937
Municipal			—		515,509		—		515,509
Total fixed income securities - available-for-sale		$	—	$	2,147,870	$	11,925	$	2,159,795
Equity securities			455,956		—		—		455,956
Other invested assets			10,620		—		—		10,620
Total		$	466,576	$	2,147,870	$	11,925	$	2,626,371

	As of December 31, 2019
	Fair Value Measurements Using
		Quoted Prices in		Significant Other		Significant
		Active Markets for		Observable		Unobservable
		Identical Assets		Inputs		Inputs
(in thousands)		(Level 1)		(Level 2)		(Level 3)		Total
Fixed income securities - available-for-sale
U.S. government		$	—	$	193,661	$	—	$	193,661
U.S. agency			—		38,855		—		38,855
Non-U.S. govt. & agency			—		7,628		—		7,628
Agency MBS			—		420,165		—		420,165
ABS/CMBS*			—		224,870		—		224,870
Corporate			—		690,297		1,770		692,067
Municipal			—		405,840		—		405,840
Total fixed income securities - available-for-sale		$	—	$	1,981,316	$	1,770	$	1,983,086
Equity securities			460,630		—		—		460,630
Total		$	460,630	$	1,981,316	$	1,770	$	2,443,716

* Non-agency asset-backed and commercial mortgage-backed

Summary of Changes in Balance of Level 3 Securities

(in thousands)	Level 3 Securities
Balance as of January 1, 2020	$	1,770
Net realized and unrealized gains (losses)
Included in net earnings as a part of:
Net investment income		(15	)
Net realized gains		(109	)
Included in other comprehensive earnings		(76	)
Total net realized and unrealized gains (losses)	$	(200	)
Purchases		10,355
Balance as of September 30, 2020	$	11,925
Change in unrealized gains (losses) during the period for Level 3 assets held at period-end - included in net realized gains	$	(109	)
Change in unrealized gains (losses) during the period for Level 3 assets held at period-end - included in other comprehensive earnings	$	(76	)

Schedule of Contractual Maturity of Securities

	September 30, 2020
(in thousands)	Amortized Cost		Fair Value
Due in one year or less	$	85,018	$	86,151
Due after one year through five years		475,999		502,636
Due after five years through 10 years		548,599		597,377
Due after 10 years		341,315		368,497
Mtge/ABS/CMBS*		580,048		605,134
Total available-for-sale	$	2,030,979	$	2,159,795

* Mortgage-backed, asset-backed and commercial mortgage-backed

Schedule of Amortized Cost and Fair Value of Available-for-sale Securities

	September 30, 2020
	Cost or		Allowance			Gross		Gross
	Amortized		for Credit			Unrealized		Unrealized			Fair
(in thousands)	Cost		Losses			Gains		Losses			Value
U.S. government	$	175,259	$	—		$	14,981	$	(36	)	$	190,204
U.S. agency		28,921		—			4,259		—			33,180
Non-U.S. govt. & agency		10,307		—			524		—			10,831
Agency MBS		376,536		—			20,617		(301	)		396,852
ABS/CMBS*		203,511		(19	)		5,347		(557	)		208,282
Corporate		750,250		(613	)		58,731		(3,431	)		804,937
Municipal		486,195		—			29,587		(273	)		515,509
Total Fixed Income	$	2,030,979	$	(632	)	$	134,046	$	(4,598	)	$	2,159,795

* Non-agency asset-backed and commercial mortgage-backed

	December 31, 2019
	Cost or		Allowance		Gross		Gross
	Amortized		for Credit		Unrealized		Unrealized			Fair
(in thousands)	Cost		Losses		Gains		Losses			Value
U.S. government	$	186,699	$	—	$	6,994	$	(32	)	$	193,661
U.S. agency		36,535		—		2,362		(42	)		38,855
Non-U.S. govt. & agency		7,333		—		295		—			7,628
Agency MBS		411,808		—		8,920		(563	)		420,165
ABS/CMBS*		222,832		—		2,514		(476	)		224,870
Corporate		659,640		—		33,245		(818	)		692,067
Municipal		390,431		—		16,131		(722	)		405,840
Total Fixed Income	$	1,915,278	$	—	$	70,461	$	(2,653	)	$	1,983,086

* Non-agency asset-backed and commercial mortgage-backed

Schedule of Debt Securities Available-for-sale Allowance for Credit Loss

	Three Months Ended			Nine Months Ended
(in thousands)	September 30, 2020			September 30, 2020
Beginning balance	$	985		$	—
Increase to allowance from securities for which credit losses were not previously recorded		17			780
Reduction from securities sold during the period		(6	)		(117	)
Reductions from intent to sell securities		(186	)		(186	)
Net increase (decrease) from securities that had an allowance at the beginning of the period		(178	)		155
Balance as of September 30,	$	632		$	632

Schedule of Securities in an Unrealized Loss Position Segregated by Type and Length of Time in an Unrealized Loss Position

	September 30, 2020									December 31, 2019
(in thousands)	< 12 Mos.			12 Mos. & Greater			Total			< 12 Mos.			12 Mos. & Greater			Total
U.S. government
Fair value	$	5,900		$	—		$	5,900		$	2,505		$	8,463		$	10,968
Amortized cost		5,936			—			5,936			2,506			8,494			11,000
Unrealized loss	$	(36	)	$	—		$	(36	)	$	(1	)	$	(31	)	$	(32	)
U.S. agency
Fair value	$	—		$	—		$	—		$	6,794		$	—		$	6,794
Amortized cost		—			—			—			6,836			—			6,836
Unrealized loss	$	—		$	—		$	—		$	(42	)	$	—		$	(42	)
Agency MBS
Fair value	$	45,929		$	244		$	46,173		$	21,548		$	41,718		$	63,266
Amortized cost		46,229			245			46,474			21,664			42,165			63,829
Unrealized loss	$	(300	)	$	(1	)	$	(301	)	$	(116	)	$	(447	)	$	(563	)
ABS/CMBS*
Fair value	$	35,837		$	14,586		$	50,423		$	74,968		$	18,036		$	93,004
Amortized cost		36,236			14,744			50,980			75,332			18,148			93,480
Unrealized loss	$	(399	)	$	(158	)	$	(557	)	$	(364	)	$	(112	)	$	(476	)
Corporate
Fair value	$	107,521		$	4,669		$	112,190		$	16,478		$	9,348		$	25,826
Amortized cost		110,664			4,957			115,621			16,950			9,694			26,644
Unrealized loss	$	(3,143	)	$	(288	)	$	(3,431	)	$	(472	)	$	(346	)	$	(818	)
Municipal
Fair value	$	32,681		$	—		$	32,681		$	47,018		$	—		$	47,018
Amortized cost		32,954			—			32,954			47,740			—			47,740
Unrealized loss	$	(273	)	$	—		$	(273	)	$	(722	)	$	—		$	(722	)
Total fixed income
Fair value	$	227,868		$	19,499		$	247,367		$	169,311		$	77,565		$	246,876
Amortized cost		232,019			19,946			251,965			171,028			78,501			249,529
Unrealized loss	$	(4,151	)	$	(447	)	$	(4,598	)	$	(1,717	)	$	(936	)	$	(2,653	)

* Non-agency asset-backed and commercial mortgage-backed

Schedule of Credit Quality Indicators for Investments in Unrealized Loss Positions

	Equivalent	Equivalent	(dollars in thousands)
NAIC	S&P	Moody’s	Amortized				Unrealized			Percent
Rating	Rating	Rating	Cost		Fair Value		Loss			to Total
1	AAA/AA/A	Aaa/Aa/A	$	152,119	$	150,542	$	(1,577	)		34.3	%
2	BBB	Baa		25,884		25,436		(448	)		9.7	%
3	BB	Ba		26,706		26,052		(654	)		14.2	%
4	B	B		42,998		41,372		(1,626	)		35.4	%
5	CCC	Caa		4,086		3,810		(276	)		6.0	%
6	CC or lower	Ca or lower		172		155		(17	)		0.4	%
		Total	$	251,965	$	247,367	$	(4,598	)		100.0	%