Leases - Supplemental Balance Sheet Information (Details) $ in Millions	Sep. 30, 2019 USD ($)
Leases [Abstract]
Operating lease right-of-use assets	$ 342
Other current liabilities	101
Other long-term liabilities	237
Total operating lease liabilities	338
Property, plant and equipment, gross	2
Accumulated depreciation	(1)
Total finance lease right-of-use assets	1
Other current liabilities	1
Other long-term liabilities	1
Total finance lease liabilities	$ 2