Cumulative Preferred Stock of Subsidiary - Additional Information (Detail) (Cumulative Preferred Stock [Member], Small Business Investment Company Subsidiaries [Member], USD $)	1 Months Ended	12 Months Ended
	Feb. 28, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Cumulative Preferred Stock [Member] | Small Business Investment Company Subsidiaries [Member]
Preferred Stock Of Subsidiary Corporation [Line Items]
Shares outstanding		30,000
Par value of shares		$ 100
Percentage of outstanding preferred stock		3.00%
Cost of redeemable preferred stock		$ 3,000,000
Value of redeemed preferred stock		900,000
Dividends		90,000	90,000	90,000
Loss on redemption of preferred stock	$ 2,100,000