Commitments, Contingencies, Guarantees, and Others - Litigation (Details) - USD ($) $ in Millions	1 Months Ended
	Oct. 31, 2018	Jul. 31, 2012	Mar. 31, 2019
Loss Contingencies [Line Items]
Loss contingency, estimate of possible loss			$ 1,100
Anti-Money laundering
Loss Contingencies [Line Items]
Litigation settlement paid	$ 100
Pending litigation | Interchange litigation
Loss Contingencies [Line Items]
Litigation settlement, attributable to reporting entity and third party		$ 6,200