Benefit Plans - Pension Obligation and Funded Status (Details) - Pension Plan - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
US
Benefit obligation
Balance at the beginning of the period	$ 357	$ 393
Service cost	5	6	$ 6
Interest cost	14	13	13
Benefits paid	(28)	(26)
Actuarial loss (gain)	39	(27)
Curtailment / settlement / amendments		(2)
Balance at the end of the period	387	357	393
Fair value of plan assets
Balance at the beginning of the period	353	404
Actual return on plan assets	82	(25)
Employer contributions	1	2
Benefits paid	(28)	(26)
Plan settlements		(2)
Balance at the end of the period	408	353	404
Funded status	21	(4)
Non-US
Benefit obligation
Balance at the beginning of the period	223	248
Service cost	3	3	3
Interest cost	10	10	11
Benefits paid	(11)	(12)
Actuarial loss (gain)	24	(8)
Curtailment / settlement / amendments	(2)
Foreign currency translation	7	(18)
Balance at the end of the period	254	223	248
Fair value of plan assets
Balance at the beginning of the period	207	235
Actual return on plan assets	24
Employer contributions	7	4
Benefits paid	(11)	(12)
Plan settlements	(3)
Foreign currency translation	7	(20)
Balance at the end of the period	231	207	$ 235
Funded status	$ (23)	$ (16)

The amount of increase or decrease due to a) an event that significantly reduces the expected years of future service of present employees or eliminates for a significant number of employees the accrual of defined benefits for some or all of their future services, b) an irrevocable action that relieves the employer (or the plan) of primary responsibility for a benefit obligation and eliminates significant risks related to the obligation and the assets used to effect the settlement, c) change in the terms of an existing plan or the initiation of a new plan. A plan amendment may increase or decrease benefits, including those attributed to years of service already rendered.

No definition available.