Commitments and Contingencies (Details Textuals) (USD $)	9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011
Commitments And Contingencies Line Items [Abstract]
Recognized Gross losses from catastrophic events	$ 22,700,000	$ 168,000,000
Liability related to indemnifications	11,200,000
Pretax loss after reinsurance	20,300,000	107,900,000
Letters of credit to cover obligations or anticipated payments	3,200,000
Amount in escrow account	$ 6,100,000