Segment Information (Schedule of Additional Business Segment Information) (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Segment Reporting Information [Line Items]
Assets	$ 1,485,533	$ 1,495,274
Specialty Commercial Segment [Member]
Segment Reporting Information [Line Items]
Assets	1,104,953	1,082,804
Standard Commercial Segment [Member]
Segment Reporting Information [Line Items]
Assets	183,689	193,710
Personal Segment [Member]
Segment Reporting Information [Line Items]
Assets	133,310	164,685
Corporate [Member]
Segment Reporting Information [Line Items]
Assets	$ 63,581	$ 54,075