Summary of Significant Accounting Policies - CARES Act (Details) $ in Millions	12 Months Ended
Dec. 31, 2021 USD ($)
Employee retention credit	$ 17
The Coronavirus Aid, Relief, and Economic Security Act \| Consolidated Appropriations Act of 2021 - PSP 2
Funding received	311
Proceeds from payroll support program grant	278
Unsecured Debt \| Consolidated Appropriations Act of 2021 - PSP 2
Unsecured low interest loan amount	$ 33
Term of grant	10 years

The cash inflow during the period from additional borrowings in aggregate debt. Includes proceeds from short-term and long-term debt.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 230
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 14
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482740/230-10-45-14

Name:	us-gaap_ProceedsFromIssuanceOfDebt
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration