Investments - Additional Information (Detail) (USD $)	12 Months Ended					24 Months Ended				12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2012 Settlement Agreement	Dec. 31, 2011 Settlement Agreement	Dec. 31, 2012 Settlement Agreement	Dec. 31, 2013 Mortgage-backed and asset-backed securities Y	Dec. 31, 2013 Non-government backed securities Maximum	Dec. 31, 2012 Non-government backed securities Maximum	Dec. 31, 2013 Non-government backed securities Investments	Dec. 31, 2012 Non-government backed securities Investments	Dec. 31, 2013 Equity Securities Maximum
Schedule of Investments [Line Items]
Non-credit OTTI on debt securities in an unrealized gain position	$ 500,000	$ 20,000
Securities, effective maturities							4.5
Gross Unrealized Loss										1,100,000	200,000
Percentage of fair value under carrying value												80.00%
Investment Expenses	3,256,000	10,386,000	7,595,000	4,500,000	4,700,000	9,200,000
Investment performance fee		2,800,000
Total Restricted Net Assets	$ 520,886,000	$ 519,201,000
Percentage of investment								5.00%	5.00%