Borrowings (Junior Subordinated Debentures) (Details) - USD ($)		1 Months Ended	12 Months Ended
	Oct. 08, 2015	Apr. 30, 2006	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2006	Dec. 31, 2008
Debt Instrument [Line Items]
Subordinated Debt	$ 15,000,000		$ 58,755,000	$ 58,599,000
Subordinated Borrowing, Interest Rate	5.50%
Debt Instrument, Term	10 years		10 years
Debt Issuance Cost			$ 54,000	9,000
Payments of Debt Issuance Costs			$ 536,000
Debt Instrument, Frequency of Periodic Payment			semi-annually
Debt Instrument, Maturity Date			Oct. 15, 2020
Debt Instrument, Call Date, Earliest			Oct. 15, 2025
Value of trust preferred securities included in Tier I Capital			$ 43,000,000	43,000,000			$ 43,000,000
Interest Expense, Junior Subordinated Debentures			3,415,000	2,724,000	$ 2,532,000
Junior Subordinated Debt [Member]
Debt Instrument [Line Items]
Value of trust preferred securities included in Tier I Capital			$ 43,000,000
Percentage of trust preferred securities included in Tier I Capital ratio			13.00%
Junior Subordinated Debt [Member] | Subsidiary One [Member]
Debt Instrument [Line Items]
Proceeds from issuance of trust preferred securities		$ 36,100,000
Value of outstanding common shares of subsidiary owned by company		$ 1,100,000
Debt instrument, interest rate		6.71%
Debt instrument, interest rate terms		now floats at the 3 month LIBOR plus 140 basis points
Debt interest rate, additional rate over three month LIBOR		1.40%
Junior Subordinated Debt [Member] | Union Bankshares Capital Trust I [Member]
Debt Instrument [Line Items]
Value of outstanding common shares of subsidiary owned by company						$ 248,000
Debt instrument, interest rate terms						The interest rate of the trust preferred securities until April 7, 2011 was a blended rate equal to the sum of (1) the product of 50% times the average three-month LIBOR plus 1.42%, plus (2) the product of 50% times 6.4725%. The rate is now the average three-month LIBOR plus 1.42%.
Debt interest rate, additional rate over three month LIBOR						1.42%
Trust preferred securities assumed in acquisition							$ 8,000,000
Aggregate amount of junior subordinated debt issued to subsidiary by acquired company, prior to acquisition						$ 8,200,000
Debt Instrument, Term						30 years
Debt instrument fixed rate						6.4725%
interest rate multiplier applied to variable rate						50.00%
interest rate multiplier applied to fixed rate						50.00%
Interest rate swaps
Debt Instrument [Line Items]
Notional amount of derivative			$ 43,000,000	$ 43,000,000