Consolidated Statements of Cash Flows (Parenthetical) - USD ($) $ in Millions	Mar. 31, 2019	Dec. 31, 2018	Mar. 31, 2018	Dec. 31, 2017
Consolidated Statements of Cash Flows [Abstract]
Cash and cash equivalents per Consolidated Balance Sheets	$ 33,177	$ 27,445	$ 31,092	$ 32,927
Restricted cash included in Other assets per Consolidated Balance Sheets	454	363	414	336
Total Cash, cash equivalents and restricted cash	$ 33,631	$ 27,808	$ 31,506	$ 33,263