Reinsurance - Current Ratings from Rating Agencies and Unsecured Net Amounts Due from Reinsurers Whose Aggregate Balance Exceeded 3% of Stockholders' Equity (Detail) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Ceded Credit Risk [Line Items]
Reinsurance unsecured amounts due from reinsurers total	$ 190,697	$ 263,572
Everest Reinsurance Company [Member] | AM Best, A+ Rating [Member] | Standard & Poor's, A+ Rating [Member] | Moody's, A1 Rating [Member]
Ceded Credit Risk [Line Items]
Reinsurance unsecured amounts due from reinsurers total	59,420	87,789
Florida Hurricane Catastrophe Fund [Member]
Ceded Credit Risk [Line Items]
Reinsurance unsecured amounts due from reinsurers total		33,593
Odyssey Reinsurance Company [Member] | AM Best, A Rating [Member] | Standard & Poor's, A- Rating [Member] | Moody's, A3 Rating [Member]
Ceded Credit Risk [Line Items]
Reinsurance unsecured amounts due from reinsurers total	$ 131,277	$ 142,190