Investments - Amortized Cost, Gross Unrealized Gains and Losses, Fair Values of Investments (Details) - USD ($) $ in Millions	Sep. 30, 2021	Dec. 31, 2020
Debt Securities
Amortized Cost	$ 558	$ 444
Gross Unrealized Gains	3	7
Gross Unrealized Losses	0	0
Fair Value	561	451
Asset-backed securities
Debt Securities
Amortized Cost	48	24
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Fair Value	48	24
Corporate bonds
Debt Securities
Amortized Cost	171	126
Gross Unrealized Gains	1	2
Gross Unrealized Losses	0	0
Fair Value	172	128
U.S. government agencies and government- sponsored agencies
Debt Securities
Amortized Cost	18	27
Gross Unrealized Gains	0	1
Gross Unrealized Losses	0	0
Fair Value	18	28
U.S. treasuries
Debt Securities
Amortized Cost	299	261
Gross Unrealized Gains	2	4
Gross Unrealized Losses	0	0
Fair Value	301	265
Certificate of deposits
Debt Securities
Amortized Cost	12	0
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Fair Value	12	0
Other debt securities
Debt Securities
Amortized Cost	10	6
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Fair Value	$ 10	$ 6

Amount, before tax, of unrealized gain in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Amount, before tax, of unrealized loss in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

+ References

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Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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-Publisher FASB
-Name Accounting Standards Codification
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