Debt Securities - Narrative (Details)	3 Months Ended
	Mar. 31, 2021 USD ($) security	Dec. 31, 2020 USD ($)
Investments, Debt and Equity Securities [Abstract]
Severity rate on available-for-sale debt securities in an unrealized loss position	5.00%
Number of credit rating categories, highest | security	4
Available-for-sale debt securities past due	$ 0	$ 0
Interest receivable, available-for-sale debt securities	22,398,000	20,215,000
ACL on available-for-sale debt securities	0
Held-to-maturity debt securities past due	0	0
Interest receivable, held-to-maturity debt securities	5,929,000	1,728,000
ACL on held-to-maturity debt securities	$ 0	$ 0