Reinsurance (Details 2) (USD $)	12 Months Ended			0 Months Ended	12 Months Ended				12 Months Ended							1 Months Ended	12 Months Ended			31 Months Ended			12 Months Ended																					12 Months Ended				12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Jun. 30, 2013 Michigan Catastrophic Claim Association	Jun. 30, 2014 Michigan Catastrophic Claim Association	Jun. 30, 2013 Michigan Catastrophic Claim Association	Dec. 31, 2013 Michigan Catastrophic Claim Association	Dec. 31, 2012 Michigan Catastrophic Claim Association	May 31, 2014 Florida Hurricane Catastrophe Fund	Dec. 31, 2013 Florida Hurricane Catastrophe Fund	Dec. 31, 2012 Florida Hurricane Catastrophe Fund	Dec. 31, 2011 Florida Hurricane Catastrophe Fund	Dec. 31, 2013 National Flood Insurance Program	Dec. 31, 2012 National Flood Insurance Program	Dec. 31, 2011 National Flood Insurance Program	Jun. 30, 2011 Catastrophe reinsurance contract layer	Dec. 31, 2013 Catastrophe reinsurance	Dec. 31, 2012 Catastrophe reinsurance	Dec. 31, 2011 Catastrophe reinsurance	Dec. 31, 2013 Top and drop excess catastrophe reinsurance agreement	Dec. 31, 2013 Top and drop excess catastrophe reinsurance agreement, coverage A	Dec. 31, 2013 Top and drop excess catastrophe reinsurance agreement, coverage B	Dec. 31, 2013 New Jersey Excess Catastrophe Reinsurance agreement contract	Dec. 31, 2013 New Jersey agreement, contract one reinstatement	Dec. 31, 2013 New Jersey agreement, contract two reinstatement	Dec. 31, 2013 New Jersey agreement, contract three reinstatement	Dec. 31, 2013 Kentucky agreement subject to three limits limit	Dec. 31, 2013 Kentucky agreement subject to two limits contract limit	Dec. 31, 2013 Pennsylvania agreement subject to three limits limit	Dec. 31, 2013 Pennsylvania agreement subject to two limits limit contract	Dec. 31, 2013 Castle Key Insurance Company and its subsidiaries agreements contract	Dec. 31, 2013 Catastrophe reinsurance, first four layers contract layer	Dec. 31, 2013 Catastrophe reinsurance, fifth layer	Dec. 31, 2013 Catastrophe reinsurance, first coverage limit of fifth layer contract	Dec. 31, 2013 Catastrophe reinsurance, second coverage limit of fifth layer contract	Dec. 31, 2013 Catastrophe reinsurance, sixth layer contract	Dec. 31, 2013 PCS excess catastrophe reinsurance agreement state contract reinstatement	Dec. 31, 2013 PCS Class B excess catastrophe reinsurance agreement	Dec. 31, 2013 PCS Class A excess catastrophe reinsurance agreement	Dec. 31, 2013 PCS excess catastrophe reinsurance agreement fifth layer	Dec. 31, 2013 PCS excess catastrophe reinsurance agreement sixth layer	Dec. 31, 2013 Lloyd's of London	Dec. 31, 2012 Lloyd's of London	Dec. 31, 2013 Property-Liability	Dec. 31, 2012 Property-Liability	Dec. 31, 2011 Property-Liability	Dec. 31, 2010 Property-Liability	Dec. 31, 2013 Property-Liability Westport Insurance Corporation	Dec. 31, 2012 Property-Liability Westport Insurance Corporation	Dec. 31, 2013 Discontinued Lines and Coverages	Dec. 31, 2012 Discontinued Lines and Coverages
Reinsurance recoverable
Total amounts recoverable from reinsurers, industry pools or facilities	$ 7,621,000,000	$ 8,767,000,000					$ 3,460,000,000	$ 2,590,000,000		$ 0	$ 0		$ 32,000,000	$ 428,000,000																												$ 191,000,000	$ 190,000,000	$ 4,750,000,000	$ 4,080,000,000
Reinsurance recoverables related to losses paid by the Company and billed to reinsurers																																												85,000,000	69,000,000
Reinsurance recoverables related to ceded unpaid losses																																												4,664,000,000	4,010,000,000	2,588,000,000	2,072,000,000
Largest reinsurance recoverable from a single reinsurer																																																85,000,000	95,000,000
Maximum amount due from any single reinsurer not separately disclosed																																												34,000,000	42,000,000
Allowance for uncollectible reinsurance																																																		92,000,000	87,000,000
Retention level per claim					530,000	500,000
Reduction in accumulated deficit				51,480,000,000
Accumulated deficit	35,580,000,000	33,783,000,000		1,870,000,000		1,870,000,000
Ceded premium earned	1,708,000,000	1,764,000,000	1,848,000,000							16,000,000	18,000,000	27,000,000	316,000,000	311,000,000	312,000,000		471,000,000	531,000,000	531,000,000
Ceded losses incurred										0	0	8,000,000	289,000,000	758,000,000	196,000,000
Percent of losses in excess of retention level to be reimbursed									90.00%
Retention level for losses related to 2 largest hurricanes									72,000,000
Retention level for losses related to other hurricanes									24,000,000
Maximum Retention level for losses related to hurricanes									198,000,000
Contracts number																5							3					1		1		3		3	2	3	2
Retention percentage of reinsurance limit																					6.33%	12.66%		32.00%	32.00%	32.00%		95.00%		95.00%		95.00%		95.00%	63.00%	38.04%				94.00%	84.37%
Limit of aggregate losses under aggregate excess agreement																				250,000,000	500,000,000	250,000,000		400,000,000	400,000,000	400,000,000	25,000,000		100,000,000		535,000,000	1,750,000,000	1,000,000,000	500,000,000	500,000,000	500,000,000		150,000,000	200,000,000
Number of separate catastrophe reinsurance agreements coordinating coverage for excess losses for Castle Key																															4
Term of catastrophe reinsurance agreement																				3 years
Term of catastrophe reinsurance agreement contract one																1 year
Term of catastrophe reinsurance agreement contract two																2 years
Term of catastrophe reinsurance agreement contract three																3 years
Number of layers in which catastrophe reinsurance agreement contracts are placed																6
Number of layers subject to reinstatement in which catastrophe reinsurance agreement contracts are placed																																4
Retention amount for catastrophe reinsurance agreement contracts																					3,250,000,000	750,000,000		134,000,000	154,000,000	150,000,000	5,000,000		100,000,000		25,000,000	500,000,000				3,250,000,000		2,750,000,000	3,250,000,000
Number of reinstatements each year for each contract																								1	1	1											0
Losses otherwise recoverable as per catastrophe reinsurance agreement contracts																						$ 500,000,000										$ 250,000,000
Number of states covered by reinsurance agreement																																					28
Number of limits																											3	2	3	2