Investment Securities (Visa Class B Restricted Shares Narrative) (Details 7)	Dec. 31, 2019 shares
Visa Class B Restricted Securities
Net Investment Income [Line Items]
Conversion ratio to Class A shares	1.6228
Equity securities remaining, shares	80,214
Visa Class A Unrestricted Securities
Net Investment Income [Line Items]
Equity securities remaining, shares	130,171