Reportable Segments, Schedule of Revenue by Major Customers, by Reporting Segments (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2016 USD ($) Segment Customer	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)
Reportable Segments [Abstract]
Number of reportable segments | Segment	2
Property and Casualty Insurance [Member] | FedEx Ground, Certain Subsidiaries, and Related Entities [Member]
Revenue, Major Customer [Line Items]
Number of major customer | Customer	1
Direct And Assumed Premiums Written	$ 18,347	$ 17,773	$ 18,951
Property and Casualty Insurance [Member] | Non-affiliated Broker on Behalf of Independent Contractors [Member]
Revenue, Major Customer [Line Items]
Direct And Assumed Premiums Written	$ 202,205	$ 209,434	$ 197,767