Nature of Operations and Summary of Significant Accounting Policies - Narrative (Details)	9 Months Ended
	Sep. 30, 2024 USD ($) quarter bankDivision operatingSegment component	Sep. 30, 2023 USD ($)	Jul. 19, 2024 branch	Dec. 31, 2023 USD ($)
Property, Plant and Equipment
Number of bank divisions | bankDivision	17
Number of operating segments | operatingSegment	1
Maximum period of original maturity to be included in cash and cash equivalents	3 months
Restricted cash	$ 21,650,000			$ 17,440,000
Federal reserve balance or cash on hand required	$ 0
Minimum period past due to consider loans as delinquent	30 days
Minimum period past due to consider loans as non accrual	90 days
Forecasting period used to determine ACL | quarter	4
Number of components used in methodology in determining ACL | component	2
Provision for credit losses on debt securities	$ 0	$ 0
Maximum term leases will be considered short-term	12 months
Maximum period up to which purchase price of business is allocated to assets acquired and liabilities assumed	1 year
Revenue from contracts with customers	$ 69,973,000	$ 65,938,000
Impairment losses on receivables related to contracts with customers	$ 0			$ 0
Rocky Mountain Bank
Property, Plant and Equipment
Number of branch locations acquired | branch			6
Minimum
Property, Plant and Equipment
Period past due to consider loan as purchased credit-deteriorated loan	90 days
Number of days delinquent to charge off loans	120 days
Number of years for home equity loan origination term	10 years
Period past due to consider loan as delinquent	30 days
Minimum | Building
Property, Plant and Equipment
Useful life of premises and equipment	15 years
Minimum | Furniture and Fixtures
Property, Plant and Equipment
Useful life of premises and equipment	3 years
Maximum
Property, Plant and Equipment
Number of years for home equity loan origination term	15 years
Period past due to consider loan as delinquent	89 days
Maximum | Building
Property, Plant and Equipment
Useful life of premises and equipment	40 years
Maximum | Furniture and Fixtures
Property, Plant and Equipment
Useful life of premises and equipment	10 years