Reinsurance (Cumulative Incurred Claims) (Details) - USD ($)	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Cumulative Incurred Claims [Line Items]
Cumulative Incurred Claims	$ 147,600,000
Claims Reserve	$ 1,600,000
Cumulative Number Of Reported Claims	140,992
Incident Year 2014 [Member]
Cumulative Incurred Claims [Line Items]
Cumulative Incurred Claims	$ 39,900,000	$ 39,900,000	$ 39,900,000	$ 39,900,000	$ 39,800,000
Claims Reserve	$ 0
Cumulative Number Of Reported Claims	40,908
Incident Year 2015 [Member]
Cumulative Incurred Claims [Line Items]
Cumulative Incurred Claims	$ 33,400,000	33,400,000	33,400,000	$ 33,100,000
Claims Reserve	$ 0
Cumulative Number Of Reported Claims	32,909
Incident Year 2016 [Member]
Cumulative Incurred Claims [Line Items]
Cumulative Incurred Claims	$ 26,000,000	26,000,000	$ 25,700,000
Claims Reserve	$ 0
Cumulative Number Of Reported Claims	25,215
Incident Year 2017 [Member]
Cumulative Incurred Claims [Line Items]
Cumulative Incurred Claims	$ 22,500,000	$ 22,300,000
Claims Reserve	$ 0
Cumulative Number Of Reported Claims	20,457
Incident Year 2018 [Member]
Cumulative Incurred Claims [Line Items]
Cumulative Incurred Claims	$ 25,800,000
Claims Reserve	$ 1,600,000
Cumulative Number Of Reported Claims	21,503