

	Amortized Cost		Allowance for Expected Credit Losses		Gross Unrealized				Fair Value
(at March 31, 2020, in millions)	Amortized Cost		Allowance for Expected Credit Losses		Gains		Losses		Fair Value
U.S. Treasury securities and obligations of U.S. government and government agencies and authorities	$	2,003	$	—	$	53	$	1	$	2,055
Obligations of states, municipalities and political subdivisions:
Local general obligation	15,893		—		907		9		16,791
Revenue	10,158		—		593		3		10,748
State general obligation	1,149		—		65		—		1,214
Pre-refunded	2,166		—		89		—		2,255
Total obligations of states, municipalities and political subdivisions	29,366		—		1,654		12		31,008
Debt securities issued by foreign governments	1,016		—		24		—		1,040
Mortgage-backed securities, collateralized mortgage obligations and pass-through securities	3,165		—		147		5		3,307
All other corporate bonds	30,034		4		816		405		30,441
Redeemable preferred stock	46		—		—		—		46
Total	$	65,630	$	4	$	2,694	$	423	$	67,897



	Amortized		Gross Unrealized				Fair
(at December 31, 2019, in millions)	Cost		Gains		Losses		Value
U.S. Treasury securities and obligations of U.S. government and government agencies and authorities	$	2,076	$	19	$	—	$	2,095
Obligations of states, municipalities and political subdivisions:
Local general obligation	15,490		829		4		16,315
Revenue	9,731		586		2		10,315
State general obligation	1,167		64		—		1,231
Pre-refunded	1,968		88		—		2,056
Total obligations of states, municipalities and political subdivisions	28,356		1,567		6		29,917
Debt securities issued by foreign governments	1,167		8		2		1,173
Mortgage-backed securities, collateralized mortgage obligations and pass-through securities	3,192		91		3		3,280
All other corporate bonds	30,442		1,195		18		31,619
Redeemable preferred stock	48		2		—		50
Total	$	65,281	$	2,882	$	29	$	68,134

Pre-refunded bonds of $2.26 billion and $2.06 billion at March 31, 2020 and December 31, 2019, respectively, were bonds for which states or municipalities have established irrevocable trusts, almost exclusively comprised of U.S. Treasury securities and obligations of U.S. government and government agencies and authorities. These trusts were created to fund the payment of principal and interest due under the bonds.

Proceeds from sales of fixed maturities classified as available for sale were $388 million and $769 million during the three months ended March 31, 2020 and 2019, respectively. Gross gains of $15 million and $21 million and gross losses of $1 million and $4 million were realized on those sales during the three months ended March 31, 2020 and 2019, respectively.



							Fair
(at March 31, 2020, in millions)	Cost		Gross Gains		Gross Losses		Value
Public common stock	$	339	$	9	$	43	$	305
Non-redeemable preferred stock	33		6		2		37
Total	$	372	$	15	$	45	$	342



							Fair
(at December 31, 2019, in millions)	Cost		Gross Gains		Gross Losses		Value
Public common stock	$	341	$	45	$	3	$	383
Non-redeemable preferred stock	35		7		—		42
Total	$	376	$	52	$	3	$	425

For the three months ended March 31, 2020 and 2019, the Company recognized $(79) million and $39 million of net gains (losses) on equity securities still held as of March 31, 2020 and 2019, respectively. Net realized investment losses on equity securities still held for the first quarter of 2020 were driven by the impact of changes in fair value attributable to the recent disruption in global financial markets associated with the global pandemic beginning in March 2020 related to the novel coronavirus COVID-19.

The following tables summarize, for all investments in an unrealized loss position at March 31, 2020 and December 31, 2019, the aggregate fair value and gross unrealized loss by length of time those securities have been continuously in an unrealized loss position. The fair value amounts reported in the tables are estimates that are prepared using the process described in note 4 herein and in note 4 of notes to the consolidated financial statements in the Company’s 2019 Annual Report. The Company also relies upon estimates of several credit and non-credit factors in its review and evaluation of individual investments, using the process described in note 1 of notes to the consolidated financial statements to determine whether credit impairment exists.



	Less than 12 months				12 months or longer				Total
(at March 31, 2020, in millions)	Fair Value		Gross Unrealized Losses		Fair Value		Gross Unrealized Losses		Fair Value		Gross Unrealized Losses
Fixed maturities
U.S. Treasury securities and obligations of U.S. government and government agencies and authorities	$	71	$	1	$	—	$	—	$	71	$	1
Obligations of states, municipalities and political subdivisions	703		12		—		—		703		12
Debt securities issued by foreign governments	5		—		—		—		5		—
Mortgage-backed securities, collateralized mortgage obligations and pass-through securities	431		5		19		—		450		5
All other corporate bonds	8,239		382		188		23		8,427		405
Redeemable preferred stock	31		—		—		—		31		—
Total	$	9,480	$	400	$	207	$	23	$	9,687	$	423



	Less than 12 months				12 months or longer				Total
(at December 31, 2019, in millions)	Fair Value		Gross Unrealized Losses		Fair Value		Gross Unrealized Losses		Fair Value		Gross Unrealized Losses
Fixed maturities
U.S. Treasury securities and obligations of U.S. government and government agencies and authorities	$	5	$	—	$	193	$	—	$	198	$	—
Obligations of states, municipalities and political subdivisions	668		6		12		—		680		6
Debt securities issued by foreign governments	257		1		147		1		404		2
Mortgage-backed securities, collateralized mortgage obligations and pass-through securities	399		2		131		1		530		3
All other corporate bonds	1,571		10		662		8		2,233		18
Total	$	2,900	$	19	$	1,145	$	10	$	4,045	$	29

At March 31, 2020, the Company had $107 million of unrealized investment losses on fixed maturity investments for which fair value has been less than 80% of amortized cost for a continuous period of three months or less. The Company determined that the unrealized losses on these securities were due to non-credit factors. These unrealized investment losses were related to "All other corporate bonds" in the foregoing table and represented less than 1% of the Company's fixed maturity investment portfolio and less than 1% of shareholders' equity at March 31, 2020. Additionally, the Company currently does not intend to and is not required to sell these investments prior to an anticipated recovery in value.



	Fixed Maturities
(for the three months ended March 31, 2020 in millions)	Mortgage-Backed Securities, Collateralized Mortgage Obligations and Pass-Through Securities		All Other Corporate Bonds		Total

Balance, Beginning of Period	$	—	$	—	$	—
Additions for expected credit losses on securities where no credit losses were previously recognized	—		4		4
Additions (reductions) for expected credit losses on securities where credit losses were previously recognized	—		—		—
Reductions due to sales/defaults of credit-impaired securities	—		—		—
Reductions for impairments of securities which the Company intends to sell or more likely than not will be required to sell ⁽¹⁾	—		—		—
Balance, End of Period	$	—	$	4	$	4

Total credit impairment charges included in net realized investment gains (losses) in the consolidated statement of income were $16 million and $1 million for the three months ended March 31, 2020 and 2019, respectively. Credit losses for the three months ended March 31, 2020 and 2019 represented less than 1% of the fixed maturity portfolio on a pre-tax basis and less than 1% of shareholders’ equity on an after-tax basis at both dates.