Document And Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2020	Mar. 01, 2021	Jun. 30, 2020
Document And Entity Information
Entity Central Index Key	0000811808
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	FY
Amendment Flag	false
Document Annual Report	true
Document Transition Report	false
Entity File Number	0-16587
Entity Incorporation, State or Country Code	WV
Entity Tax Identification Number	55-0672148
Entity Address, Postal Zip Code	26836
Entity Address, State or Province	WV
Entity Address, City or Town	Moorefield
Entity Address, Address Line One	300 N. Main Street
City Area Code	304
Local Phone Number	530-1000
Trading Symbol	SMMF
Security Exchange Name	NASDAQ
Title of 12(b) Security	Common
Entity Interactive Data Current	Yes
Document Type	10-K
Document Period End Date	Dec. 31, 2020
Current Fiscal Year End Date	--12-31
Entity Registrant Name	Summit Financial Group, Inc.
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Shell Company	false
Entity Public Float			$ 181,887,000
Entity Common Stock, Shares Outstanding		12,985,708
Entity Filer Category	Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
ICFR Auditor Attestation Flag	true