Reinsurance Reinsurance - Narrative (Details) (USD $)	0 Months Ended	3 Months Ended		6 Months Ended			0 Months Ended				0 Months Ended
	Jan. 02, 2014	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013	Dec. 31, 2013	Jun. 01, 2014 First Catastrophic Event [Member] Rate	Jun. 01, 2014 Second Catastrophic Event [Member] Rate	Jun. 01, 2013 Unaffiliated Private Reinsurers [Member] Maximum [Member]	Jun. 01, 2013 Catastrophe [Member] Florida Hurricane Catastrophe Fund [Member]	Jun. 01, 2014 Catastrophe [Member] First Catastrophic Event [Member]	Jun. 01, 2014 Catastrophe [Member] First Catastrophic Event [Member] Insurance Affiliate [Member] Rate	Jun. 01, 2014 Catastrophe [Member] First Catastrophic Event [Member] Reinsurance Affiliate [Member] [Member] Rate	Jun. 01, 2014 Catastrophe [Member] Second Catastrophic Event [Member]	Jun. 01, 2014 Catastrophe [Member] Second Catastrophic Event [Member] Unaffiliated Private Reinsurers [Member]	Jun. 01, 2013 Catastrophe [Member] Second Catastrophic Event [Member] Unaffiliated Private Reinsurers [Member]
Reinsurance Retention Policy [Line Items]
Reinsurance Retention Policy, Excess Retention, Amount Reinsured	$ 500,000						$ 1,080,200,000.00	$ 15,000,000.00
Reinsurance, Aggregate Value of Property Covered Under Contracts										555,200,000
Reinsurance, Losses Not Covered Prior to Coverage Beginning										230,800,000
Reinsurance Retention Policy, Amount Retained	500,000										25,000,000	17,500,000	7,500,000	10,000,000	15,000,000
Aggregate Coverage for Covered Losses Under Reinsurance Contract									525,000,000
Reinsurance Coverage, Percentage Retained												70.00%	30.00%
Reinsurance Coverage, Percentage Placed							100.00%	100.00%
Prepaid Reinsurance Premiums		131,896,000		131,896,000		55,268,000				41,700,000						90,600,000
Reinsurance Costs and Recoveries, Net		664,000	1,223,000	1,081,000	1,471,000
Percentage of Flood Premiums Ceded				100.00%
Insurance Commissions and Fees, Flood Program		$ 162,000	$ 188,000	$ 580,000	$ 268,000