Investment Securities - Narrative (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2021 USD ($) security	Dec. 31, 2020 USD ($)
Investments, Debt and Equity Securities [Abstract]
Number of available-for-sale investments | security	453
Number of securities in an unrealized loss position | security	85
Percentage of available-for-sale securities	84.60%
Accrued interest receivable	$ 2,300
Securities pledged as collateral	218,700	$ 282,300
Accrued interest receivable on held to maturity debt securities	31
Investment securities held in trading accounts	$ 8,266	$ 8,623
Number of held-to-maturity securities in an unrealized loss position | security	2