Statutory Financial Information of Insurance Subsidiaries (Narratives) (Details) - Operating Segments [Member] - USD ($) $ in Millions	12 Months Ended
	Mar. 31, 2017	Dec. 31, 2017
Property and Casualty Insurance [Member] | Repwest [Member]
Statutory financial information of insurance subsidiaries:
Statutory accounting practices, statutory amount available for dividend payments		$ 16.3
Dividend payments restrictions schedule, amounts paid	$ 19.6
Life Insurance [Member] | Oxford [Member]
Statutory financial information of insurance subsidiaries:
Statutory accounting practices, statutory amount available for dividend payments		$ 10.4