FAIR VALUE (Tables)

9 Months Ended

Sep. 30, 2021

Fair Value Disclosures [Abstract]

Schedule of Financial Assets Measured at Fair Value on Recurring Basis

The following table summarizes our fair value measurements at September 30, 2021 and December 31, 2020, respectively, for financial assets measured at fair value on a recurring basis:

	Fair Value Measurements Using
	Fair Value		Quoted Prices in Active Markets (Level 1)		Other Observable Inputs (Level 2)		Unobservable Inputs (Level 3)
	(in millions)
September 30, 2021
Cash equivalents	$	3,894	$	3,894	$	—	$	—
Debt securities:
U.S. Treasury and other U.S. government     corporations and agencies:
U.S. Treasury and agency obligations	650		—		650		—
Mortgage-backed securities	3,722		—		3,722		—
Tax-exempt municipal securities	886		—		886		—
Mortgage-backed securities:
Residential	389		—		389		—
Commercial	1,468		—		1,468		—
Asset-backed securities	1,400		—		1,400		—
Corporate debt securities	5,598		—		5,598		—
Total debt securities	14,113		—		14,113		—
Common stock	701		701		—		—
Total invested assets	$	18,708	$	4,595	$	14,113	$	—
December 31, 2020
Cash equivalents	$	4,548	$	4,548	$	—	$	—
Debt securities:
U.S. Treasury and other U.S. government     corporations and agencies:
U.S. Treasury and agency obligations	616		—		616		—
Mortgage-backed securities	3,254		—		3,254		—
Tax-exempt municipal securities	1,447		—		1,447		—
Mortgage-backed securities:
Residential	17		—		17		—
Commercial	1,318		—		1,318		—
Asset-backed securities	1,372		—		1,372		—
Corporate debt securities	4,927		—		4,927		—
Total debt securities	12,951		—		12,951		—
Common stock	815		815		—		—
Total invested assets	$	18,314	$	5,363	$	12,951	$	—