v3.20.4
Parent Company - Condensed Consolidated Statements of Cash Flows (Parenthetical) (Detail) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
SUPPLEMENTAL DISCLOSURES:      
Cash payments for interest, net of capitalized interest $ 9,091 $ 18,645 $ 16,721
Cash payments/(refunds) for income taxes, net 2,754 1,266 1,271
Group Inc. [Member]      
SUPPLEMENTAL DISCLOSURES:      
Cash payments for interest, net of capitalized interest 5,920 9,530 9,830
Cash payments to subsidiaries for interest, net of capitalized interest 1,900 3,010 3,050
Cash payments/(refunds) for income taxes, net $ 1,370 $ 272 $ (98)