Subsequent Events (Narrative) (Details) - USD ($)			6 Months Ended
	Jul. 31, 2018	Jan. 16, 2018	Jun. 30, 2018	Dec. 31, 2017
Subsequent Event [Line Items]
Total assets			$ 1,415,647,000	$ 1,170,354,000
Total deposits			$ 1,236,518,000	$ 1,023,568,000
Subsequent Event [Member]
Subsequent Event [Line Items]
Acquisition completion date	Jul. 31, 2018
First Priority Financial Corp. [Member]
Subsequent Event [Line Items]
Plan of merger agreement, date		Jan. 16, 2018
Shares of acquirer ratio of common stock		34.81%
Per share price		$ 11.07
Period prior to closing of merger for calculating average price			30 days
Total assets			$ 627,428,000
Total bank loans			522,036,000
Total deposits			$ 513,582,000
First Priority Financial Corp. [Member] | Subsequent Event [Member]
Subsequent Event [Line Items]
Business Acquisition, Equity Interest Issued or Issuable, Number of Shares	2,300,000
Payments to Acquire Businesses, Gross	$ 3,900,000
Number of outstanding preferred shares issued in exchange	3,404
Business Combination, Consideration Transferred	$ 79,904,000
First Priority Financial Corp. [Member] | Subsequent Event [Member] | Series D Preferred Stock [Member]
Subsequent Event [Line Items]
Preferred Stock, Shares Issued	3,404
Preferred Stock, Dividend Rate, Percentage	9.00%