Loans, Lending Commitments and Allowance for Credit Losses - Impaired Loans and Total Allowance by Region (Details) - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018
Impaired Loans
Impaired loans	$ 357	$ 125
Total Allowance for loan losses	297	238
Americas
Impaired Loans
Impaired loans	357	125
Total Allowance for loan losses	227	193
EMEA
Impaired Loans
Impaired loans	0	0
Total Allowance for loan losses	64	42
Asia
Impaired Loans
Impaired loans	0	0
Total Allowance for loan losses	$ 6	$ 3

Amount of allowance to cover probable credit losses on loans and leases. Includes carryover of or adjustments to the allowance for loan losses in connection with business combinations. Excludes allowance for loans and leases covered under loss sharing agreements.

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