Investment Securities - Additional Information (Details)	3 Months Ended
	Mar. 31, 2022 USD ($) Security	Dec. 31, 2021 USD ($) Security
Schedule Of Available For Sale Securities [Line Items]
Equity securities, at fair value	$ 369,000	$ 397,000
Tax rate used to calculate tax-equivalent yields (in hundredths)	21.00%
Percentage investment book value exceeds stockholders' equity (in hundredths)	10.00%
Debt securities, available-for-sale, restricted	$ 665,000,000	590,000,000
Available-for-sale, 12 months or longer, Fair Value	319,139,000	186,350,000
12 months or longer, unrealized losses	$ 34,538,000	$ 4,627,000
U.S. Treasury Securities and Obligations of U.S. Government Corporations and Agencies
Schedule Of Available For Sale Securities [Line Items]
Number of securities in unrealized loss positions | Security	14	6
Available-for-sale, 12 months or longer, Fair Value	$ 116,577,000	$ 139,846,000
12 months or longer, unrealized losses	$ 11,117,000	$ 2,936,000
Held-to-maturity, securities in unrealized loss positions, qualitative disclosure, number of positions | Security		0
Obligations of States and Political Subdivisions
Schedule Of Available For Sale Securities [Line Items]
Number of securities in unrealized loss positions | Security	5	0
Available-for-sale, 12 months or longer, Fair Value	$ 6,399,000	$ 0
12 months or longer, unrealized losses	$ 1,241,000	$ 0
Mortgage-backed Securities: GSE Residential
Schedule Of Available For Sale Securities [Line Items]
Number of securities in unrealized loss positions | Security	42	15
Available-for-sale, 12 months or longer, Fair Value	$ 193,648,000	$ 46,504,000
12 months or longer, unrealized losses	$ 22,122,000	$ 1,691,000
Other Securities
Schedule Of Available For Sale Securities [Line Items]
Number of securities in unrealized loss positions | Security	3	0
Available-for-sale, 12 months or longer, Fair Value	$ 2,515,000	$ 0
12 months or longer, unrealized losses	$ 58,000	$ 0