Income Taxes - Valuation Allowances Narrative (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Other Tax Carryforward [Line Items]
Carryforwards	$ 441	$ 526
Valuation allowance	222	237	$ 76	$ 132
Deferred tax assets, net operating losses	312
Deferred tax assets, tax credit carryforwards	129
Deferred tax assets, tax credit carryforwards, expiring within 5 years	6
Deferred tax assets, tax credit carryforwards, expiring after 5 years	113
Deferred tax assets, tax credit carryforwards, no expiration	10
Accrued income taxes	664
Undistributed earnings of foreign subsidiaries	31,000
Unrecognized tax benefits	472	$ 319	$ 54	$ 56
United States
Other Tax Carryforward [Line Items]
Deferred tax assets, net operating losses, expiring within 5 years	55
Deferred tax assets, net operating losses, expiring after 5 years	115
Brazil
Other Tax Carryforward [Line Items]
Deferred tax assets, net operating losses, no expiration	$ 142