Segment Information (Schedule of Additional Business Segment Information) (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Segment Reporting Information [Line Items]
Assets	$ 1,433,170	$ 1,495,274
Specialty Commercial Segment [Member]
Segment Reporting Information [Line Items]
Assets	1,031,263	1,082,804
Standard Commercial Segment [Member]
Segment Reporting Information [Line Items]
Assets	184,155	193,710
Personal Segment [Member]
Segment Reporting Information [Line Items]
Assets	156,691	164,685
Corporate [Member]
Segment Reporting Information [Line Items]
Assets	$ 61,061	$ 54,075