Other Assets (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Other Assets [Abstract]
Goodwill	$ 3,315	$ 3,072	$ 3,009
Other intangible assets, at amortized cost	267	275
Other	11,149	10,031
Total	$ 14,731	$ 13,378