Guarantees and Commitments Guarantees and Commitments (Other Purchase Commitments) (Details) $ in Millions	Dec. 31, 2017 USD ($)
Guarantees and Commitments [Abstract]
Other Commitment, Due in Next Twelve Months	$ 85
Other Commitment, Due in Second and Third Year	36
Other Commitment, Due in Fourth Year	2
Other Commitment	$ 123

Minimum amount of other commitment maturing in the second and third fiscal years following the latest fiscal year for commitments not otherwise specified in the taxonomy. Excludes commitments explicitly modeled in this taxonomy, including but not limited to, long-term and short-term purchase commitments, recorded and unrecorded purchase obligations, supply commitments, registration payment arrangements, leases, debt, product warranties, guarantees, environmental remediation obligations, and pensions.

No definition available.

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