Goodwill and Other Intangible Assets - Narrative (Details) - USD ($)			3 Months Ended			12 Months Ended
	Oct. 31, 2021	Oct. 15, 2021	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Jun. 30, 2021	Sep. 01, 2020
Goodwill and Intangible Assets Disclosure [Abstract]
Balance of servicing assets						$ 5,500,000
Servicing assets recorded						2,000,000.0	$ 2,200,000
Servicing fee income						3,900,000	3,300,000	$ 2,600,000
Amortization of SBA servicing assets						2,272,000	1,795,000	1,340,000
SBA servicing asset						414,200,000	395,400,000
Intangibles amortization						3,531,000	3,956,000	4,858,000
Goodwill impairment	$ 0		$ 0	$ 0	$ 0
Business Acquisition [Line Items]
Goodwill						$ 364,263,000	$ 239,272,000	$ 234,368,000
Discontinued Operations, Disposed of by Sale | First Bank Insurance Services
Business Acquisition [Line Items]
Finite-lived intangible assets									$ 2,800,000
Select
Business Acquisition [Line Items]
Goodwill		$ 132,356,000
Magnolia Financial, Inc.
Business Acquisition [Line Items]
Intangible assets deductible for tax purposes										$ 1,600,000
Minimum
Business Acquisition [Line Items]
Identifiable intangible assets, useful life						5 years
Core Deposits | Select
Business Acquisition [Line Items]
Finite-lived intangibles acquired		$ 9,200,000
Core Deposits | Minimum
Business Acquisition [Line Items]
Identifiable intangible assets, useful life						10 years
Customer Lists | Discontinued Operations, Disposed of by Sale | First Bank Insurance Services
Business Acquisition [Line Items]
Finite-lived intangible assets									$ 2,800,000
Customer Lists | Minimum
Business Acquisition [Line Items]
Identifiable intangible assets, useful life						5 years