Office Properties and Equipment, net - Schedule of Office Properties and Equipment (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Property, Plant and Equipment [Line Items]
Office property and equipment, gross	$ 145,273	$ 133,141
Less accumulated depreciation and amortization	(66,565)	(57,167)
Total office properties and equipment, net	78,708	75,974
Land
Property, Plant and Equipment [Line Items]
Office property and equipment, gross	12,900	10,174
Buildings
Property, Plant and Equipment [Line Items]
Office property and equipment, gross	36,897	31,523
Land and building improvements
Property, Plant and Equipment [Line Items]
Office property and equipment, gross	36,683	35,307
Leasehold improvements
Property, Plant and Equipment [Line Items]
Office property and equipment, gross	22,636	22,166
Furniture and equipment
Property, Plant and Equipment [Line Items]
Office property and equipment, gross	$ 36,157	$ 33,971