Income Taxes - Provision for Income Taxes (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Currently payable
Federal	$ 534	$ 698	$ 1,022
State	59	109	59
International	673	763	722
Tax Cuts and Jobs Act (TCJA) non-current transition tax provision		176	623
Deferred
Federal	(32)	(38)	162
State	(26)	(17)	15
International	(78)	(54)	76
Total provision for income taxes	$ 1,130	$ 1,637	$ 2,679

The noncurrent transition tax provision specific to the Tax Cuts and Jobs Act of 2017.

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