Employee Benefits (Narrative) (Details) - USD ($)		3 Months Ended	12 Months Ended
	Jul. 30, 2015	Jun. 30, 2015	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Jul. 21, 2015	May. 31, 2014
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Contributions to the plans			$ 360,000	$ 362,000	$ 354,000
Contributions to the ESOP			$ 429,000	$ 714,000	$ 173,000
Shares owned by ESOP			588,193	321,449
Stock Issued During Period, Shares, Employee Stock Ownership Plan			26,511
Stock Issued During Period, Value, Employee Stock Ownership Plan			$ 312,000
Employee Stock Ownership Plan (ESOP), Number of Suspense Shares			181,822
Common stock, shares authorized			20,000,000	20,000,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Net of Forfeitures			166,717	0	0
Supplemental Employee Retirement Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Accrued liabilities			$ 4,300,000	$ 3,900,000
2014 LTIP [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Common stock, shares authorized							500,000
Summit Financial Group Inc. Employee Stock Ownership Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Stock Issued During Period, Shares, Employee Stock Ownership Plan	225,000
Employee Stock Ownership Plan (ESOP), Weighted Average Purchase Price of Shares Purchased	$ 10.80
Stock Issued During Period, Value, Employee Stock Ownership Plan	$ 2,430,000
Employee Stock Ownership Plan (ESOP), Debt Structure, Indirect Loan, Amount						$ 2,250,000
Employee Stock Ownership Plan (ESOP), Number of Suspense Shares						208,333
Stock Appreciation Rights (SARs) [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Net of Forfeitures		166,717
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period		5 years
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage		20.00%
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period		10 years
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate			1.96%
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Dividend Rate			2.75%
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Volatility Rate			61.84%
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Term			10 years