Regulatory Capital Requirements (Tables)

12 Months Ended

Dec. 31, 2021

Broker-Dealer, Net Capital Requirement, SEC Regulation [Abstract]

Schedule of Compliance with Regulatory Capital Requirements under Banking Regulations

The Company and its banking subsidiary’s actual capital amounts and ratios as of December 31, 2021 and 2020 are presented in the following table:

	Actual				Minimum Required For Capital Adequacy Purposes				Minimum Required Plus Capital Conservation Buffer				To Be Well Capitalized Under Prompt Corrective Action Provision
	Amount		Ratio		Amount		Ratio		Amount		Ratio		Amount		Ratio
	(dollars in thousands)
December 31, 2021
CET1 Capital (to risk-weighted assets):
The Company	$	1,710,981	13.01	%	$	591,585	4.50	%	$	920,244	7.00	%	N/A		N/A
Columbia Bank	$	1,716,186	13.06	%	$	591,154	4.50	%	$	919,754	7.00	%	$	853,890	6.50	%
Tier 1 Capital (to risk-weighted assets):
The Company	$	1,710,981	13.01	%	$	788,780	6.00	%	$	1,117,439	8.50	%	N/A		N/A
Columbia Bank	$	1,716,186	13.06	%	$	788,206	6.00	%	$	1,116,625	8.50	%	$	1,050,941	8.00	%
Total Capital (to risk-weighted assets):
The Company	$	1,868,192	14.21	%	$	1,051,707	8.00	%	$	1,380,366	10.50	%	N/A		N/A
Columbia Bank	$	1,863,397	14.18	%	$	1,050,941	8.00	%	$	1,379,360	10.50	%	$	1,313,677	10.00	%
Tier 1 Capital Leverage (to average assets):
The Company	$	1,710,981	8.55	%	$	800,615	4.00	%	$	800,615	4.00	%	N/A		N/A
Columbia Bank	$	1,716,186	8.60	%	$	798,206	4.00	%	$	798,206	4.00	%	$	997,757	5.00	%
December 31, 2020
CET1 Capital (to risk-weighted assets):
The Company	$	1,390,958	12.88	%	$	486,080	4.50	%	$	756,125	7.00	%	N/A		N/A
Columbia Bank	$	1,411,834	13.08	%	$	485,775	4.50	%	$	755,651	7.00	%	$	701,676	6.50	%
Tier 1 Capital (to risk-weighted assets):
The Company	$	1,390,958	12.88	%	$	648,107	6.00	%	$	918,152	8.50	%	N/A		N/A
Columbia Bank	$	1,411,834	13.08	%	$	647,700	6.00	%	$	917,576	8.50	%	$	863,601	8.00	%
Total Capital (to risk-weighted assets):
The Company	$	1,561,020	14.45	%	$	864,143	8.00	%	$	1,134,187	10.50	%	N/A		N/A
Columbia Bank	$	1,546,804	14.33	%	$	863,601	8.00	%	$	1,133,476	10.50	%	$	1,079,501	10.00	%
Tier 1 Capital Leverage (to average assets):
The Company	$	1,390,958	8.86	%	$	628,112	4.00	%	$	628,112	4.00	%	N/A		N/A
Columbia Bank	$	1,411,834	9.08	%	$	622,171	4.00	%	$	622,171	4.00	%	$	777,714	5.00	%