Quarterly report pursuant to Section 13 or 15(d)

Revenue Recognition Revenue Recognition (Contract Liabilities Rollforward) (Details)

v3.21.2
Revenue Recognition Revenue Recognition (Contract Liabilities Rollforward) (Details) - USD ($)
$ in Millions
6 Months Ended
Jun. 30, 2021
Jun. 30, 2020
Revenue Recognition and Deferred Revenue [Abstract]    
Contract liabilities, Beginning Balance $ 448 $ 539
Contract with Customer, Liability, Additions 145 145
Contract with Customer, Liability, Revenue Recognized 174 149
Contract liabilities, Ending Balance $ 419 $ 535