Investment Securities (Visa Class B Restricted Shares Narrative) (Details 8) $ in Thousands |
12 Months Ended | ||
---|---|---|---|
Dec. 31, 2017
USD ($)
shares
|
Dec. 31, 2016
USD ($)
|
Dec. 31, 2015
USD ($)
|
|
Net Investment Income [Line Items] | |||
Net Gains on Sales of Investment Securities | $ | $ 10,430 | $ 10,203 | $ 10,160 |
Visa Class B Restricted Securities | |||
Net Investment Income [Line Items] | |||
Conversion ratio to Class A shares | 1.6483 | ||
Net Gains on Sales of Investment Securities | $ | $ 12,100 | ||
Sale of investment securities, shares | 90,000 | ||
Equity securities remaining, shares | 86,614 | ||
Visa Class A Unrestricted Securities | |||
Net Investment Income [Line Items] | |||
Equity securities remaining, shares | 142,766 |