Investments - Amortized Cost, Gross Unrealized Gains and Losses, Fair Values of Investments (Details) - USD ($) $ in Millions	Jun. 30, 2020	Dec. 31, 2019
Debt Securities
Amortized Cost	$ 444	$ 341
Gross Unrealized Gains	9	1
Gross Unrealized Losses	0	0
Fair Value	453	342
Asset-backed securities
Debt Securities
Amortized Cost	22	30
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Fair Value	22	30
Corporate bonds
Debt Securities
Amortized Cost	111	123
Gross Unrealized Gains	3	1
Gross Unrealized Losses	0	0
Fair Value	114	124
U.S. government agencies and government- sponsored agencies
Debt Securities
Amortized Cost	24	14
Gross Unrealized Gains	1	0
Gross Unrealized Losses	0	0
Fair Value	25	14
U.S. treasuries
Debt Securities
Amortized Cost	280	163
Gross Unrealized Gains	5	0
Gross Unrealized Losses	0	0
Fair Value	285	163
Certificate of deposits
Debt Securities
Amortized Cost	0	1
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Fair Value	0	1
Other debt securities
Debt Securities
Amortized Cost	7	10
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Fair Value	$ 7	$ 10

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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-Publisher FASB
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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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