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Goodwill and Intangible Assets - Narrative (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Jan. 29, 2021
Finite-Lived Intangible Assets [Line Items]
Goodwill	$ 75,717,000	$ 0
Amortization expense	5,200,000	3,100,000	$ 3,500,000
Impairment of intangible assets	$ 0	$ 0	$ 0
Customer Relationships \| Minimum
Finite-Lived Intangible Assets [Line Items]
Intangible assets, amortized period	10 years
Customer Relationships \| Maximum
Finite-Lived Intangible Assets [Line Items]
Intangible assets, amortized period	14 years
Radius Bancorp, Inc
Finite-Lived Intangible Assets [Line Items]
Goodwill				$ 75,717,000