Basis of Presentation (Details Textuals) - USD ($) $ in Millions	Mar. 31, 2020	Jan. 01, 2020	Dec. 31, 2019	Mar. 31, 2019	Dec. 31, 2018
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Total receivable reserves decrease	$ (459)		$ (619)	$ (608)
Offset to retained earnings	$ (12,161)		(13,871)
Accounting Standards Update 2016-13 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Total loan reserves increase		$ 1,663
Total receivable reserves decrease		493	$ (126)		$ (573)
Current and deferred tax impact		288
Offset to retained earnings		$ 882