Loans Payable - Additional Information (Detail) (USD $)			0 Months Ended		3 Months Ended	0 Months Ended
	Mar. 31, 2014 CreditFacility	Dec. 31, 2013	Mar. 17, 2014 Clarendon Facility [Member]	Mar. 31, 2014 Clarendon Facility [Member]	Mar. 31, 2014 SeaBright Facility [Member]	Mar. 26, 2014 EGL Revolving Credit Facility [Member]	Mar. 31, 2014 EGL Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Number of outstanding credit facilities	3
Loans payable outstanding, including accrued interest	$ 485,239,000	$ 452,446,000
Amount borrowed under facility agreement						70,000,000
Unused portion of Credit Facility							46,200,000
Repayment of outstanding principal balance			13,000,000		22,000,000
Outstanding principal amount	$ 483,795,000	$ 448,795,000		$ 66,000,000	$ 89,000,000