Junior Subordinated Debentures Held by Trust Subsidiaries - Summary of Junior Subordinated Debentures (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Debt Instrument [Line Items]
Amount of Trust Preferred Securities Issued by Trust	$ 62,250	$ 62,250
Principal Amount of Debenture Issued to Trust	64,178	64,178
Commercebank Capital Trust VI | Junior Subordinated Debt | Junior Subordinated Notes, Maturing 2033
Debt Instrument [Line Items]
Principal Amount of Debenture Issued to Trust	$ 9,537	9,537
Commercebank Capital Trust VI | Junior Subordinated Debt | Junior Subordinated Notes, Maturing 2033 | 3-month LIBOR
Debt Instrument [Line Items]
Variable rate	3.35%
Commercebank Capital Trust VII | Junior Subordinated Debt | Junior Subordinated Notes, Maturing 2033
Debt Instrument [Line Items]
Principal Amount of Debenture Issued to Trust	$ 8,248	8,248
Commercebank Capital Trust VII | Junior Subordinated Debt | Junior Subordinated Notes, Maturing 2033 | 3-month LIBOR
Debt Instrument [Line Items]
Variable rate	3.25%
Commercebank Capital Trust VIII | Junior Subordinated Debt | Junior Subordinated Notes, Maturing 2034
Debt Instrument [Line Items]
Principal Amount of Debenture Issued to Trust	$ 5,155	5,155
Commercebank Capital Trust VIII | Junior Subordinated Debt | Junior Subordinated Notes, Maturing 2034 | 3-month LIBOR
Debt Instrument [Line Items]
Variable rate	2.85%
Commercebank Capital Trust IX | Junior Subordinated Debt | Junior Subordinated Notes, Maturing 2038
Debt Instrument [Line Items]
Principal Amount of Debenture Issued to Trust	$ 25,774	25,774
Commercebank Capital Trust IX | Junior Subordinated Debt | Junior Subordinated Notes, Maturing 2038 | 3-month LIBOR
Debt Instrument [Line Items]
Variable rate	1.75%
Commercebank Capital Trust X | Junior Subordinated Debt | Junior Subordinated Notes, Maturing 2036
Debt Instrument [Line Items]
Principal Amount of Debenture Issued to Trust	$ 15,464	15,464
Commercebank Capital Trust X | Junior Subordinated Debt | Junior Subordinated Notes, Maturing 2036 | 3-month LIBOR
Debt Instrument [Line Items]
Variable rate	1.78%
Commercebank Capital Trust VI | Junior Subordinated Notes, Maturing 2033
Debt Instrument [Line Items]
Amount of Trust Preferred Securities Issued by Trust	$ 9,250	9,250
Commercebank Capital Trust VII | Junior Subordinated Notes, Maturing 2033
Debt Instrument [Line Items]
Amount of Trust Preferred Securities Issued by Trust	8,000	8,000
Commercebank Capital Trust VIII | Junior Subordinated Notes, Maturing 2034
Debt Instrument [Line Items]
Amount of Trust Preferred Securities Issued by Trust	5,000	5,000
Commercebank Capital Trust IX | Junior Subordinated Notes, Maturing 2038
Debt Instrument [Line Items]
Amount of Trust Preferred Securities Issued by Trust	25,000	25,000
Commercebank Capital Trust X | Junior Subordinated Notes, Maturing 2036
Debt Instrument [Line Items]
Amount of Trust Preferred Securities Issued by Trust	$ 15,000	$ 15,000