Securities (Narrative) (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2021 USD ($) security shares	Jun. 30, 2020 shares	Dec. 31, 2020 USD ($)	Mar. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)
Debt Securities, Available-for-sale [Line Items]
Interest receivable | $	$ 52,667		$ 54,831
Unrealized gains recognized during the reporting period on equity securities still held at the reporting date | $	$ 0
Visa Class B shares, shares sold | shares		17,360
Visa Class B shares, remaining shares | shares	77,683
Equity Securities | $	$ 13,425		13,425	$ 0	$ 0
Available-for-sale Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Interest receivable | $	$ 17,400		$ 17,100
U.S. Government Agency and Government-Sponsored Enterprise Mortgage-Backed Securities and Collateralized Mortgage Obligations [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions | security	144
Asset-backed Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions | security	16
State and Municipal Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions | security	89
U.S. Government and Government-Sponsored Enterprise Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions | security	8