XML 52 R39.htm IDEA: XBRL DOCUMENT v3.20.4
Description of Business, Accounting Policies, and Supplemental Disclosures - Fair Value of Financial Instruments (Details) - USD ($)
$ in Millions
Dec. 31, 2020
Dec. 31, 2019
Fair Value, Inputs, Level 2 | Equity Warrant    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Fair value of warrants $ 3,000 $ 669