Investment Securities, Contractual Maturity (Details) $ in Thousands	Mar. 31, 2022 USD ($)
Amortized Cost [Abstract]
One year or less	$ 10,268
After one year through five years	5,160
After five years through ten years	5,455
After ten years	5,204
Amortized cost, excluding securities without single maturity date	26,087
Securities not due at a single maturity date	269,221
Fair Value [Abstract]
One year or less	10,310
After one year through five years	5,073
After five years through ten years	5,326
After ten years	5,221
Fair value, excluding investment securities not due at a single maturity date	25,930
Securities not due at a single maturity date	251,375
Amortized Cost [Abstract]
One year or less	908
After one year through five years	7,118
After five years through ten years	16,690
After ten years	38,865
Fair value, excluding securities without single maturity date	63,581
Securities not due at a single maturity date	876,257
Fair Value [Abstract]
One year or less	908
After one year through five years	7,113
After five years through ten years	16,846
After ten years	38,811
Fair value, excluding investment securities without single maturity date	63,678
Securities not due at a single maturity date	810,909
Mortgage-backed Securities [Member]
Amortized Cost [Abstract]
Securities not due at a single maturity date	241,585
Fair Value [Abstract]
Securities not due at a single maturity date	223,901
Amortized Cost [Abstract]
Securities not due at a single maturity date	695,249
Fair Value [Abstract]
Securities not due at a single maturity date	634,599
Collateralized Mortgage Obligations [Member]
Amortized Cost [Abstract]
Securities not due at a single maturity date	1,549
Fair Value [Abstract]
Securities not due at a single maturity date	1,544
Amortized Cost [Abstract]
Securities not due at a single maturity date	117,427
Fair Value [Abstract]
Securities not due at a single maturity date	$ 112,632