Employee Benefits - Narrative (Details) $ in Millions	3 Months Ended
	Mar. 31, 2020 USD ($)
Defined Benefit Plan Disclosure [Line Items]
Pre-Medicare company contribution for retiree medical coverage, maximum percent	4.00%
Defined benefit plan, expected future employer contributions, remainder of fiscal year	$ 1,000
Contribution to other post retirement plans	41
United States
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, expected future employer contributions, remainder of fiscal year	750
International
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, expected future employer contributions, remainder of fiscal year	250
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, contributions by employer to employee pension plan	213
Pension Benefits | United States
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, contributions by employer to employee pension plan	134
Other Benefits
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, expected contributions during the remaining of fiscal year	$ 133