Other Assets (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Other Assets Details [Abstract]
Goodwill	$ 3,072	$ 3,009	$ 2,927
Deferred Tax Assets, Net	1,480	1,637
Prepaid expenses	1,458	684
Other intangible assets, at amortized cost	275	899
Community Reinvestment Act Tax Credit Investments	1,043	1,023
Restricted cash	363	336	$ 286
Derivative assets	396	124
Other	2,384	2,034
Other assets	$ 10,471	$ 9,746