Summary of Significant Accounting Policies and Practices (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Summary of Significant Accounting Policies and Practices [Abstract]
Maximum number of years for which claims incurred			10 years
Change in Accounting Estimate [Line Items]
Increase in net income	$ 10,593	$ 7,227	$ 31,611	$ 27,204
Decrease in gross ceded premiums	119,985	129,298	231,046	179,137
Increase in loss and loss adjustment expenses	28,412	15,126	75,510	60,476
Increase in deferred acquisition costs			(88)	(5,728)
Increase in prepaid reinsurance premiums			40,967	31,610
Increase (decrease) in reinsurance recoverable			(4,186)	6,494
Decrease in deferred policy acquisition costs	6,788	$ 5,815	16,938	$ 23,095
Change in Accounting Method Accounted for as Change in Estimate [Member] | Quota Share Reinsurance Adjustments [Member]
Change in Accounting Estimate [Line Items]
Increase in net income	2,200		2,200
Decrease in gross ceded premiums	(10,900)		(10,900)
Increase in loss and loss adjustment expenses	4,500		4,500
Increase in deferred acquisition costs	1,500		1,500
Increase in prepaid reinsurance premiums	10,900		10,900
Increase (decrease) in reinsurance recoverable	(4,500)		(4,500)
Decrease in deferred policy acquisition costs	1,500		1,500
Contingent quota-share profit sharing reclassified to prepaid reinsurance premiums	14,000		14,000
Deferred quota-share profit sharing reclassified to reinsurance recoverable	$ 7,000		$ 7,000