Indebtedness - Summary of Other Non-Recourse Debt (Details) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Debt Instrument [Line Items]
Other nonrecourse debt principal amount	$ 4,671	$ 5,286
Participating interest financing \| Minimum
Debt Instrument [Line Items]
Interest Rate	0.30%
Participating interest financing \| Maximum
Debt Instrument [Line Items]
Interest Rate	5.60%
Trust 2020-1 \| Minimum
Debt Instrument [Line Items]
Interest Rate	1.30%
Trust 2020-1 \| Maximum
Debt Instrument [Line Items]
Interest Rate	7.50%
Trust 2019-2 \| Minimum
Debt Instrument [Line Items]
Interest Rate	2.30%
Trust 2019-2 \| Maximum
Debt Instrument [Line Items]
Interest Rate	6.00%
Trust 2019-1 \| Minimum
Debt Instrument [Line Items]
Interest Rate	2.70%
Trust 2019-1 \| Maximum
Debt Instrument [Line Items]
Interest Rate	6.00%
Trust 2018-3 \| Minimum
Debt Instrument [Line Items]
Interest Rate	3.60%
Trust 2018-3 \| Maximum
Debt Instrument [Line Items]
Interest Rate	6.00%
Trust 2018-2 \| Minimum
Debt Instrument [Line Items]
Interest Rate	3.20%
Trust 2018-2 \| Maximum
Debt Instrument [Line Items]
Interest Rate	6.00%
Nonrecourse debt–legacy assets
Debt Instrument [Line Items]
Other nonrecourse debt principal amount	$ 4,671	5,286
Unamortized debt issuance costs, premium and discount	6	10
Nonrecourse debt–legacy assets \| Participating interest financing
Debt Instrument [Line Items]
Collateral Amount	0
Other nonrecourse debt principal amount	3,664	4,284
Nonrecourse debt–legacy assets \| Trust 2020-1
Debt Instrument [Line Items]
Collateral Amount	519
Other nonrecourse debt principal amount	516	0
Nonrecourse debt–legacy assets \| Trust 2019-2
Debt Instrument [Line Items]
Collateral Amount	275
Other nonrecourse debt principal amount	259	333
Nonrecourse debt–legacy assets \| Trust 2019-1
Debt Instrument [Line Items]
Collateral Amount	248
Other nonrecourse debt principal amount	226	302
Nonrecourse debt–legacy assets \| Trust 2018-3
Debt Instrument [Line Items]
Collateral Amount	0
Other nonrecourse debt principal amount	0	209
Nonrecourse debt–legacy assets \| Trust 2018-2
Debt Instrument [Line Items]
Collateral Amount	0
Other nonrecourse debt principal amount	0	148
Nonrecourse debt–legacy assets \| Other
Debt Instrument [Line Items]
Other nonrecourse debt principal amount	$ 4,665	$ 5,276

Amount of assets pledged to secure a debt instrument.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 470
-Section 50
-Paragraph 3
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=75038535&loc=d3e64711-112823

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- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22(a)(1))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

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- Definition

Amount of unamortized debt discount (premium) and debt issuance costs.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 4
-Subparagraph (b)(2)
-URI http://asc.fasb.org/extlink&oid=120520924&loc=SL6031897-161870

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=119993939&loc=d3e28555-108399

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- Definition

Amount of debt for which creditor does not have general recourse to the debtor but rather has recourse only to the property used for collateral in the transaction or other specific property.

+ References

No definition available.

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