Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2020	Feb. 02, 2021	Jun. 30, 2020	Dec. 31, 2019
Document and Entity Information [Abstract]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2020
Document Transition Report	false
Entity File Number	000-18911
Entity Registrant Name	GLACIER BANCORP, INC.
Entity Incorporation, State or Country Code	MT
Entity Tax Identification Number	81-0519541
Entity Address, Address Line One	49 Commons Loop
Entity Address, City or Town	Kalispell,
Entity Address, State or Province	MT
Entity Address, Postal Zip Code	59901
City Area Code	(406)
Local Phone Number	756-4200
Title of 12(b) Security	Common Stock, $0.01 par value
Trading Symbol	GBCI
Security Exchange Name	NASDAQ
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
ICFR Auditor Attestation Flag	true
Entity Shell Company	false
Entity Public Float			$ 3,355,430,758
Entity Common Stock, Shares Outstanding		95,426,364
Documents Incorporated by Reference	Portions of the 2021 Annual Meeting Proxy Statement dated on or about March 16, 2021 are incorporated by reference into Parts I and III of this Form 10-K.
Common stock, par value	$ 0.01			$ 0.01
Entity Central Index Key	0000868671
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	FY
Amendment Flag	false