Commitments and Contingencies (Details Textuals) (USD $)	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Commitments And Contingencies Line Items [Abstract]
Liability related to indemnifications	$ 8,400,000
Pretax cat loss after reinsurance	5,200,000	7,600,000
Letters of credit to cover obligations or anticipated payments	$ 3,200,000
Longest Indemnification Expiration Date	2025