Long-Term Debt - Letters of Credit (Details) - Letter of credit - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Debt Instrument [Line Items]
Letters of credit outstanding	$ 9	$ 18
Collateralized debt obligations
Debt Instrument [Line Items]
Letters of credit outstanding	$ 5	$ 11

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.

No definition available.

Name:	us-gaap_DebtInstrumentLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration