Reinsurance (Details)			3 Months Ended		6 Months Ended
	Jun. 01, 2016 USD ($) catastrophic_event layer reinsurer Rate	Jan. 01, 2016 USD ($)	Jun. 30, 2016 USD ($)	Jun. 30, 2015 USD ($)	Jun. 30, 2016 USD ($)	Jun. 30, 2015 USD ($)	Dec. 31, 2015 USD ($)
Reinsurance Retention Policy [Line Items]
Prepaid reinsurance premiums			$ 180,747,000		$ 180,747,000		$ 79,399,000
Cash recoveries under reinsurance agreements			591,000	$ 116,000	$ 857,000	$ 927,000
Flood premiums ceded (percentage)					100.00%
Insurance commissions and fees under Flood Program			$ 256,000	$ 241,000	$ 502,000	$ 482,000
Minimum
Reinsurance Retention Policy [Line Items]
ISO Catastrophe Definition	$ 25,000,000
Catastrophe
Reinsurance Retention Policy [Line Items]
Percentage of losses covered | Rate	100.00%
Prepaid reinsurance premiums	$ 191,500,000
Catastrophe | Maximum
Reinsurance Retention Policy [Line Items]
Stated amount of upper retention limit per policy	$ 10,000,000
Catastrophe | First Catastrophic Event [Member]
Reinsurance Retention Policy [Line Items]
Reinsurance Retention Policy, Coverage Percentage Hurricane Event | catastrophic_event	0.010
Percentage of losses covered | Rate	100.00%
Catastrophe | First Catastrophic Event [Member] | Maximum
Reinsurance Retention Policy [Line Items]
Amount of risk reinsured in excess of stated retention	$ 1,415,197,000
Stated amount of upper retention limit per policy	$ 30,000,000
Catastrophe | Second Catastrophic Event [Member]
Reinsurance Retention Policy [Line Items]
Reinsurance Retention Policy, Coverage Percentage Hurricane Event | catastrophic_event	0.020
Catastrophe | Second And Subsequent Catastrophic Events [Member]
Reinsurance Retention Policy [Line Items]
Amount of risk reinsured in excess of stated retention	$ 100,000,000
Catastrophe | Second And Subsequent Catastrophic Events [Member] | Maximum
Reinsurance Retention Policy [Line Items]
Amount of risk reinsured in excess of stated retention	$ 1,515,197,000
Catastrophe | Florida Hurricane Catastrophe Fund [Member] | FLORIDA
Reinsurance Retention Policy [Line Items]
Reimbursement percentage	45.00%
Reinsurance, Aggregate Value of Property Covered Under Contracts	$ 786,700,000
Reinsurance, Losses Not Covered Prior to Coverage Beginning	246,002,000
Aggregate Coverage for Covered Losses Under Reinsurance Contract	$ 354,015,000
Catastrophe | Unaffiliated Private Reinsurers [Member]
Reinsurance Retention Policy [Line Items]
Number of private reinsurers | reinsurer	55
Number of cascading insurance layers | layer	5
Catastrophe | Unaffiliated Private Reinsurers [Member] | Maximum
Reinsurance Retention Policy [Line Items]
Stated amount of upper retention limit per policy	$ 10,000,000
Aggregate Coverage for Covered Losses Under Reinsurance Contract	$ 685,000,000
Catastrophe | Unaffiliated Private Reinsurers [Member] | FLORIDA
Reinsurance Retention Policy [Line Items]
Reimbursement percentage	45.00%
Reinsurance, Aggregate Value of Property Covered Under Contracts	$ 769,293,000
Reinsurance, Losses Not Covered Prior to Coverage Beginning	244,206,000
Aggregate Coverage for Covered Losses Under Reinsurance Contract	346,182,000
United Property & Casualty Insurance Company | Windstorm [Member] | Maximum
Reinsurance Retention Policy [Line Items]
Stated amount of upper retention limit per policy		$ 15,000,000
United Property & Casualty Insurance Company | Catastrophe | Maximum
Reinsurance Retention Policy [Line Items]
Aggregate Coverage for Covered Losses Under Reinsurance Contract		$ 20,000,000
UPC Re | Catastrophe | Maximum
Reinsurance Retention Policy [Line Items]
Stated amount of upper retention limit per policy	$ 20,000,000