Reinsurance - Schedule of the Effect of Reinsurance on Premiums Written and Earned (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Premiums Written And Earned [Abstract]
Gross Written	$ 372,177	$ 328,823	$ 272,101
Ceded Written	(18,425)	(16,305)	(13,881)
Net premiums Written	353,752	312,518	258,220
Gross Earned	348,408	306,994	264,896
Ceded Earned	(18,425)	(16,305)	(13,881)
Net premiums Earned	$ 329,983	$ 290,689	$ 251,015