Reinsurance (Schedule Of Reinsurance Activity) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Reinsurance [Abstract]
Net assumed written premiums	$ 42.4	$ 40.6	$ 45.0
Net premiums earned	41.1	43.0	48.2
Provision for claims	22.7	26.0	33.2
Amortization of capitalized acquisition costs	$ 1.0	$ 1.1	$ 1.2