Reinsurance - Narrative (Details) - USD ($) $ in Thousands		12 Months Ended
	Jun. 01, 2015	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]
Prepaid Reinsurance Premiums		$ 79,399	$ 63,827
Policyholder Benefits and Claims Incurred, Assumed and Ceded		$ 10,282	2,667
Percentage of Flood Premiums Ceded		100.00%
Insurance Commissions and Fees, Flood Program		$ 959	$ 1,078	$ 570
Increase (Decrease) in Ceded Losses and LAE Incurred		(10,608)
Minimum [Member]
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]
ISO Catastrophe Definition		$ 25,000
Catastrophe [Member]
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]
Prepaid Reinsurance Premiums	$ 161,000
UPC, Subsidiary [Member] | Catastrophe [Member] | Maximum [Member]
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]
Reinsurance Retention Policy, Excess Retention, Amount Reinsured	1,243,122
Reinsurance Retention Policy, Amount Retained	25,000
UPC, Subsidiary [Member] | Catastrophe [Member] | Florida Hurricane Catastrophe Fund [Member]
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]
Aggregate Coverage for Covered Losses Under Reinsurance Contract	284,061
UPC, Subsidiary [Member] | Catastrophe [Member] | Unaffiliated Private Reinsurers [Member] | Maximum [Member]
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]
Aggregate Coverage for Covered Losses Under Reinsurance Contract	$ 585,000
FLORIDA | UPC, Subsidiary [Member] | Catastrophe [Member]
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]
Reinsurance Coverage, Percentage Placed	100.00%
FLORIDA | UPC, Subsidiary [Member] | Catastrophe [Member] | Florida Hurricane Catastrophe Fund [Member]
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]
Reinsurance Retention Policy, Participation Rate	45.00%
Reinsurance, Aggregate Value of Property Covered Under Contracts	$ 631,247
Reinsurance, Losses Not Covered Prior to Coverage Beginning	230,356
Windstorm [Member] | UPC, Subsidiary [Member] | Catastrophe [Member]
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]
Reinsurance Retention Policy, Excess Retention, Amount Reinsured	20,000
Reinsurance Retention Policy, Amount Retained	5,000
Aggregate Coverage for Covered Losses Under Reinsurance Contract	$ 40,000