See Note 5, "Fair Value" for additional fair value disclosures. The following tables summarize the cost and fair value, net of credit loss allowance, of our available-for-sale securities as of:



	June 30, 2021
(in thousands)	Amortized cost		Gross unrealized gains		Gross unrealized losses		Estimated fair value






Corporate debt securities	$	548,975	$	16,666	$	952	$	564,689
Collateralized debt obligations	115,087		574		219		115,442
Commercial mortgage-backed securities	109,277		3,378		363		112,292
Residential mortgage-backed securities	92,142		1,811		301		93,652
Other debt securities	28,905		462		35		29,332
U.S. Treasury	20,648		743		0		21,391



Total available-for-sale securities, net	$	915,034	$	23,634	$	1,870	$	936,798



	December 31, 2020
(in thousands)	Amortized cost		Gross unrealized gains		Gross unrealized losses		Estimated fair value







Corporate debt securities	$	546,096	$	21,843	$	1,514	$	566,425
Collateralized debt obligations	110,121		657		331		110,447
Commercial mortgage-backed securities	115,346		5,090		235		120,201
Residential mortgage-backed securities	108,840		3,373		34		112,179
Other debt securities	18,387		606		9		18,984
Total available-for-sale securities, net	$	898,790	$	31,569	$	2,123	$	928,236

The amortized cost and estimated fair value of available-for-sale securities at June 30, 2021 are shown below by remaining contractual term to maturity. Expected maturities may differ from contractual maturities because borrowers may have the right to call or prepay obligations with or without call or prepayment penalties.



	June 30, 2021
	Amortized		Estimated
(in thousands)	cost		fair value

Due in one year or less	$	20,580	$	20,856
Due after one year through five years	429,579		442,409
Due after five years through ten years	194,317		197,441
Due after ten years	270,558		276,092
Total available-for-sale securities	$	915,034	$	936,798

The below securities have been evaluated and determined to be temporary declines in fair value for which we expect to recover our entire principal plus interest. The following tables present available-for-sale securities based on length of time in a gross unrealized loss position as of:



	June 30, 2021
	Less than 12 months				12 months or longer				Total
(dollars in thousands)	Fair value		Unrealized losses		Fair value		Unrealized losses		Fair value		Unrealized losses		No. of holdings





Corporate debt securities	$	80,035	$	584	$	8,703	$	368	$	88,738	$	952	289
Collateralized debt obligations	45,288		148		16,642		71		61,930		219		73
Commercial mortgage-backed securities	9,240		329		476		34		9,716		363		21
Residential mortgage-backed securities	29,064		301		0		0		29,064		301		46
Other debt securities	5,606		35		0		0		5,606		35		7




Total available-for-sale securities	$	169,233	$	1,397	$	25,821	$	473	$	195,054	$	1,870	436
Quality breakdown of available-for-sale securities:
Investment grade	$	140,765	$	1,212	$	17,262	$	107	$	158,027	$	1,319	174
Non-investment grade	28,468		185		8,559		366		37,027		551		262
Total available-for-sale securities	$	169,233	$	1,397	$	25,821	$	473	$	195,054	$	1,870	436



	December 31, 2020
	Less than 12 months				12 months or longer				Total
(dollars in thousands)	Fair value		Unrealized losses		Fair value		Unrealized losses		Fair value		Unrealized losses		No. of holdings





Corporate debt securities	$	39,693	$	644	$	7,952	$	870	$	47,645	$	1,514	257
Collateralized debt obligations	50,036		232		10,899		99		60,935		331		65
Commercial mortgage-backed securities	16,582		235		0		0		16,582		235		31
Residential mortgage-backed securities	8,163		34		0		0		8,163		34		13
Other debt securities	1,019		9		0		0		1,019		9		4
Total available-for-sale securities	$	115,493	$	1,154	$	18,851	$	969	$	134,344	$	2,123	370




Quality breakdown of available-for-sale securities:
Investment grade	$	86,807	$	561	$	10,899	$	99	$	97,706	$	660	119
Non-investment grade	28,686		593		7,952		870		36,638		1,463		251
Total available-for-sale securities	$	115,493	$	1,154	$	18,851	$	969	$	134,344	$	2,123	370

As of June 30, 2021 and December 31, 2020, the current expected credit loss allowance on agent loans was $1.1 million in both periods. The current expected credit loss on available-for-sale securities was less than $0.1 million at June 30, 2021, and $0.2 million at December 31, 2020.



	Three months ended June 30,				Six months ended June 30,
(in thousands)	2021		2020		2021		2020

Available-for-sale securities	$	5,790	$	5,670	$	11,987	$	11,458
Equity securities	1,116		901		2,318		1,757
Limited partnerships (1)	6,151		(2,329)		15,197		(6,034)
Cash equivalents and other	935		1,115		1,912		3,089
Total investment income	13,992		5,357		31,414		10,270
Less: investment expenses	342		313		667		562
Investment income, net of expenses	$	13,650	$	5,044	$	30,747	$	9,708

(1)Equity in earnings (losses) of limited partnerships includes both realized gains (losses) and unrealized valuation changes. Our limited partnership investments are included in the line item "Other assets" in the Statements of Financial Position. We have made no new limited partnership commitments since 2006, and the balance of limited partnership investments is expected to decline over time as additional distributions are received.



	Three months ended June 30,				Six months ended June 30,
(in thousands)	2021		2020		2021		2020

Available-for-sale securities:

Gross realized gains	$	1,075	$	1,721	$	2,998	$	2,795
Gross realized losses	(678)		(1,366)		(1,118)		(1,825)
Net realized gains on available-for-sale securities	397		355		1,880		970




Equity securities (1)	2,371		6,170		1,692		(5,252)










Miscellaneous	1		1		1		2
Net realized investment gains (losses)	$	2,769	$	6,526	$	3,573	$	(4,280)

(1)While our investment portfolio was negatively impacted in the first quarter of 2020 primarily due to the financial market volatility resulting from the COVID-19 pandemic, market conditions partially recovered in the second quarter of 2020, resulting in significant gains in the three months ended June 30, 2020.


	Three months ended June 30,				Six months ended June 30,
(in thousands)	2021		2020		2021		2020
Equity securities:
Net gains (losses) recognized during the period (1)	$	2,371	$	6,170	$	1,692	$	(5,252)
Less: net gains (losses) recognized on securities sold	128		1,357		(293)		(2,157)
Net unrealized gains (losses) recognized on securities held at reporting date	$	2,243	$	4,813	$	1,985	$	(3,095)



	Three months ended June 30,				Six months ended June 30,
(in thousands)	2021		2020		2021		2020
Available-for-sale securities:
Intent to sell	$	—	$	—	$	—	$	(2,242)
Credit (impaired) recovered	(1)		(17)		86		(658)
Total available-for-sale securities	(1)		(17)		86		(2,900)
Agent loans - expected credit losses	—		—		—		(170)
Net impairment (losses) recoveries recognized in earnings	$	(1)	$	(17)	$	86	$	(3,070)