Segment Information (Schedule of Additional Business Segment Information) (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Segment Reporting Information [Line Items]
Assets	$ 1,173,224	$ 1,162,460
Specialty Commercial Segment [Member]
Segment Reporting Information [Line Items]
Assets	742,205	734,763
Standard Commercial Segment [Member]
Segment Reporting Information [Line Items]
Assets	164,219	164,295
Personal Segment [Member]
Segment Reporting Information [Line Items]
Assets	242,708	241,686
Corporate [Member]
Segment Reporting Information [Line Items]
Assets	$ 24,092	$ 21,716