Senior and Subordinated Debt - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended				12 Months Ended		3 Months Ended	12 Months Ended
	Dec. 31, 2012	Sep. 25, 2012	Dec. 31, 2011	Jul. 22, 2011	Dec. 31, 2012 LFB [Member]	Dec. 31, 2012 Edgewater [Member]	Sep. 30, 2011 Subordinated Debt [Member]	Dec. 31, 2012 Revolving credit facility [Member]
Debt Instrument [Line Items]
Senior revolving credit facility over next 3 years		$ 150,000
Senior Debt, Maturity Date								Sep. 25, 2015
Duration of senior revolving credit facility, in years		3 years
Revolving credit facility annual interest rate								0.92%
Outstanding credit facility	0		0
Unused lines of credit available	301,000				92,000	55,000
Promissory note representing subordinated debt, outstanding				150,000
Subordinated promissory note, at cost				131,829
Pre-tax gain resulted from repurchasing of subordinated note							$ 18,171