Pension Benefits (Details) - USD ($) $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Defined Benefit Plan Disclosure [Line Items]
Payment for Pension Benefits				$ 1	$ 11
UNITED STATES
Defined Benefit Plan Disclosure [Line Items]
Net periodic benefit cost		$ 4	$ 2	9	4
UNITED STATES | General and Administrative Expense [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost		2	1	4	3
UNITED STATES | Other pension (income) expense [Member]
Defined Benefit Plan Disclosure [Line Items]
Interest cost		8	10	17	20
Expected return on plan assets		(11)	(11)	(22)	(22)
Amortization of net loss		3	1	7	1
Amortization of prior service cost		2	1	3	2
Additional loss (gain) recognized due to settlements	[1]	$ 0	$ 0	$ 0	$ 2

[1] Loss is a result of settlement transactions which exceeded the sum of annual service and interest costs for the applicable plan. These losses were recorded in Other pension (income) expense.