FAIR VALUE (Tables)

6 Months Ended

Jun. 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 June 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)
June 30, 2021
Cash equivalents	$	3,191	$	3,191	$	—	$	—
Debt securities:
U.S. Treasury and other U.S. government     corporations and agencies:
U.S. Treasury and agency obligations	641		—		641		—
Mortgage-backed securities	3,530		—		3,530		—
Tax-exempt municipal securities	1,094		—		1,094		—
Mortgage-backed securities:
Residential	256		—		256		—
Commercial	1,453		—		1,453		—
Asset-backed securities	1,458		—		1,458		—
Corporate debt securities	5,428		—		5,428		—
Total debt securities	13,860		—		13,860		—
Common stock	793		793		—		—
Total invested assets	$	17,844	$	3,984	$	13,860	$	—
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	$	—