Maximum potential amount of future payments (undiscounted) the guarantor could be required to make under the guarantee or each group of similar guarantees before reduction for potential recoveries under recourse or collateralization provisions.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 460
-SubTopic 10
-Section 50
-Paragraph 4
-Subparagraph (b)(1)
-URI http://asc.fasb.org/extlink&oid=118943654&loc=d3e12069-110248

Name:	us-gaap_GuaranteeObligationsMaximumExposure
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Leases Narrative (Details) - USD ($) $ in Millions	4 Months Ended	8 Months Ended	12 Months Ended
Leases Narrative (Details) - USD ($) $ in Millions	Dec. 31, 2017	Aug. 31, 2017	Dec. 31, 2019	Dec. 31, 2018
Operating Leases, Rent Expense, Net	$ 86	$ 100		$ 225
Guarantee Obligations			$ 97	$ 299
Residual Value Guarantee [Member]
Guarantee Obligations			$ 278
Minimum [Member]
Remaining Lease Term			1 year
Maximum [Member]
Remaining Lease Term			52 years