Segment Information (Schedule of Additional Business Segment Information) (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Segment Reporting Information [Line Items]
Assets	$ 1,463,534	$ 1,264,894
Specialty Commercial Segment [Member]
Segment Reporting Information [Line Items]
Assets	1,055,106	858,262
Standard Commercial Segment [Member]
Segment Reporting Information [Line Items]
Assets	192,285	158,881
Personal Segment [Member]
Segment Reporting Information [Line Items]
Assets	170,715	226,431
Corporate [Member]
Segment Reporting Information [Line Items]
Assets	$ 45,428	$ 21,320