Subsequent Events a (Details) - USD ($)	3 Months Ended	9 Months Ended	12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Dec. 31, 2016
Subsequent Event [Line Items]
Catastrophe reinsurance retention		$ 4,000,000
Scenario, Forecast [Member] | Hurricane [Member]
Subsequent Event [Line Items]
Decrease in pre-tax income	$ (4,000,000)
Decrease in net income	$ (2,640,000)
Percent of losses retained	100.00%		100.00%
Catastrophe reinsurance retention			$ 4,000,000
Reinsurer's limit of liability			72,500,000
Scenario, Forecast [Member] | Hurricane [Member] | Minimum [Member]
Subsequent Event [Line Items]
Reinsurance losses for unpaid claims and claims adjustments	$ 7,000,000		$ 7,000,000
Excess retention, percentage			100.00%
Scenario, Forecast [Member] | Hurricane [Member] | Maximum [Member]
Subsequent Event [Line Items]
Reinsurance losses for unpaid claims and claims adjustments	$ 8,000,000		$ 8,000,000