Segment Information (Schedule of Business Segment Information) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Revenues [Abstract]
Revenues	$ 118,121	$ 93,341
Pre-tax income (loss) [Abstract]
Pre-tax income (loss)	18,918	809
Specialty Commercial Segment [Member]
Revenues [Abstract]
Revenues	67,967	73,124
Pre-tax income (loss) [Abstract]
Pre-tax income (loss)	7,968	9,758
Standard Commercial Segment [Member]
Revenues [Abstract]
Revenues	18,373	18,875
Pre-tax income (loss) [Abstract]
Pre-tax income (loss)	1,507	1,319
Personal Segment [Member]
Revenues [Abstract]
Revenues	19,483	7,620
Pre-tax income (loss) [Abstract]
Pre-tax income (loss)	1,573	(22)
Corporate [Member]
Revenues [Abstract]
Revenues	12,298	(6,278)
Pre-tax income (loss) [Abstract]
Pre-tax income (loss)	$ 7,870	$ (10,246)