Regulatory Capital (Details) $ in Thousands	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)
Regulatory Capital
Capital conservation buffer	2.50%
Total capital (to risk-weighted assets)
Actual, amount	$ 2,629,557	$ 2,432,364
Actual, ratio	0.1402	0.1421
Minimum capital requirement, amount	$ 1,500,096	$ 1,369,157
Minimum capital requirement, ratio	0.0800	0.0800
Tier 1 capital (to risk-weighted assets)
Actual, amount	$ 2,314,322	$ 2,136,749
Actual, ratio	0.1234	0.1249
Minimum capital requirement, amount	$ 1,125,072	$ 1,026,868
Minimum capital requirement, ratio	0.0600	0.0600
Common Equity Tier 1 (to risk-weighted assets)
Actual, amount	$ 2,314,322	$ 2,136,749
Actual, ratio	0.1234	0.1249
Minimum capital requirement, amount	$ 843,804	$ 770,151
Minimum capital requirement, ratio	4.50%	4.50%
Tier 1 capital (to average assets)
Actual, amount	$ 2,314,322	$ 2,136,749
Actual, ratio	0.0879	0.0864
Minimum capital requirement, amount	$ 1,053,214	$ 989,712
Minimum capital requirement, ratio	0.0400	0.0400
Glacier Bank
Total capital (to risk-weighted assets)
Actual, amount	$ 2,544,147	$ 2,312,775
Actual, ratio	0.1358	0.1353
Minimum capital requirement, amount	$ 1,498,264	$ 1,367,488
Minimum capital requirement, ratio	0.0800	0.0800
Well capitalized requirement, amount	$ 1,872,830	$ 1,709,361
Well capitalized requirement, ratio	0.1000	0.1000
Tier 1 capital (to risk-weighted assets)
Actual, amount	$ 2,359,412	$ 2,147,660
Actual, ratio	0.1260	0.1256
Minimum capital requirement, amount	$ 1,123,698	$ 1,025,616
Minimum capital requirement, ratio	0.0600	0.0600
Well capitalized requirement, amount	$ 1,498,264	$ 1,367,488
Well capitalized requirement, ratio	0.0800	0.0800
Common Equity Tier 1 (to risk-weighted assets)
Actual, amount	$ 2,359,412	$ 2,147,660
Actual, ratio	0.1260	0.1256
Minimum capital requirement, amount	$ 842,774	$ 769,212
Minimum capital requirement, ratio	4.50%	4.50%
Well capitalized requirement, amount	$ 1,217,340	$ 1,111,084
Well capitalized requirement, ratio	6.50%	6.50%
Tier 1 capital (to average assets)
Actual, amount	$ 2,359,412	$ 2,147,660
Actual, ratio	0.0897	0.0870
Minimum capital requirement, amount	$ 1,052,136	$ 987,680
Minimum capital requirement, ratio	0.0400	0.0400
Well capitalized requirement, amount	$ 1,315,169	$ 1,234,601
Well capitalized requirement, ratio	0.0500	0.0500