Postretirement Benefit Plans (Textuals) (Details) - USD ($) $ in Millions		3 Months Ended		9 Months Ended		12 Months Ended
	Jul. 31, 2019	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block
Other postretirement benefit expense			$ 1	$ 1
Amortization of net actuarial loss		$ 1	1	2	$ 2
Employer contribution to defined benefit plan			19	14	37
Increase to losses in AOCI		11	0	11	0
Minimum
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block
Additional contributions		4		4
Maximum
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block
Additional contributions		8		8
Foreign Plan [Member]
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block
Amortization of net actuarial loss		2	2	6	7
Lump sum payment		21
Settlement		8	$ 0	$ 8	$ 1
Remeasurement of plan's projected benefit obligation	$ 37
Plan assets remeasurement	26
Increase to losses in AOCI	$ 11
Expected rate of return	7.25%					0.70%
Discount rate	2.00%					3.00%
Incremental net periodic benefit cost		$ 3