Investments (Tables)

3 Months Ended

Mar. 31, 2021

Short-Term and Long-Term Investments [Table Text Block]

A summary of debt securities by major security type is as follows:


(in millions)	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Fair Value
March 31, 2021
Debt securities - available-for-sale:
U.S. government and agency obligations	$	3,372	$	86	$	(26)	$	3,432
State and municipal obligations	6,941		345		(22)		7,264
Corporate obligations	20,395		533		(122)		20,806
U.S. agency mortgage-backed securities	6,784		185		(48)		6,921
Non-U.S. agency mortgage-backed securities	2,382		66		(19)		2,429
Total debt securities - available-for-sale	39,874		1,215		(237)		40,852
Debt securities - held-to-maturity:
U.S. government and agency obligations	418		5		—		423
State and municipal obligations	31		2		—		33
Corporate obligations	190		—		—		190
Total debt securities - held-to-maturity	639		7		—		646
Total debt securities	$	40,513	$	1,222	$	(237)	$	41,498
December 31, 2020
Debt securities - available-for-sale:
U.S. government and agency obligations	$	3,335	$	133	$	(3)	$	3,465
State and municipal obligations	6,893		435		—		7,328
Corporate obligations	18,886		863		(12)		19,737
U.S. agency mortgage-backed securities	6,849		245		(3)		7,091
Non-U.S. agency mortgage-backed securities	2,116		95		(4)		2,207
Total debt securities - available-for-sale	38,079		1,771		(22)		39,828
Debt securities - held-to-maturity:
U.S. government and agency obligations	420		6		—		426
State and municipal obligations	31		2		—		33
Corporate obligations	187		1		—		188
Total debt securities - held-to-maturity	638		9		—		647
Total debt securities	$	38,717	$	1,780	$	(22)	$	40,475

Investments by Contractual Maturity [Table Text Block]

The amortized cost and fair value of debt securities as of March 31, 2021, by contractual maturity, were as follows:


	Available-for-Sale				Held-to-Maturity
(in millions)	Amortized Cost		Fair Value		Amortized Cost		Fair Value
Due in one year or less	$	3,037	$	3,053	$	354	$	355
Due after one year through five years	12,571		12,922		238		242
Due after five years through ten years	10,945		11,263		25		26
Due after ten years	4,155		4,264		22		23
U.S. agency mortgage-backed securities	6,784		6,921		—		—
Non-U.S. agency mortgage-backed securities	2,382		2,429		—		—
Total debt securities	$	39,874	$	40,852	$	639	$	646

Fair Value of Available-for-Sale Investments with Gross Unrealized Losses by Investment Type and Length of Time that Individual Securities have been in a Continuous Unrealized Loss Position [Table Text Block]

The fair value of available-for-sale debt securities with gross unrealized losses by major security type and length of time that individual securities have been in a continuous unrealized loss position were as follows:


	Less Than 12 Months				12 Months or Greater				Total
(in millions)	Fair Value		Gross Unrealized Losses		Fair Value		Gross Unrealized Losses		Fair Value		Gross Unrealized Losses
March 31, 2021
Debt securities - available-for-sale:
U.S. government and agency obligations	$	924	$	(26)	$	—	$	—	$	924	$	(26)
State and municipal obligations	1,141		(22)		3		—		1,144		(22)
Corporate obligations	5,266		(120)		367		(2)		5,633		(122)
U.S. agency mortgage-backed securities	2,552		(48)		1		—		2,553		(48)
Non-U.S. agency mortgage-backed securities	650		(17)		77		(2)		727		(19)
Total debt securities - available-for-sale	$	10,533	$	(233)	$	448	$	(4)	$	10,981	$	(237)
December 31, 2020
Debt securities - available-for-sale:
U.S. government and agency obligations	$	346	$	(3)	$	—	$	—	$	346	$	(3)
Corporate obligations	1,273		(9)		456		(3)		1,729		(12)
U.S. agency mortgage-backed securities	601		(3)		—		—		601		(3)
Non-U.S. agency mortgage-backed securities	195		(1)		93		(3)		288		(4)
Total debt securities - available-for-sale	$	2,415	$	(16)	$	549	$	(6)	$	2,964	$	(22)