Debt - Summary of Debt (Parenthetical) (Detail) (USD $)	9 Months Ended		3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Aug. 31, 2013 Debenture [Member]	Mar. 31, 2013 Debenture [Member]	Sep. 30, 2013 Debenture [Member]	Sep. 01, 2013 Debenture [Member]
Debt Instrument [Line Items]
Total debt	$ 104,505,000		$ 8,500,000	$ 6,000,000
SBIC debenture interest rate			3.64%	2.35%
Annual fees			0.76%	0.515%
Debenture maturity period					10 years
Repayment of Debentures						4,190,000
Debt instrument, maturity period					Sep. 01, 2013
Proceeds on revolving credit facility	47,800,000	34,400,000
Repayments on revolving credit facility	$ 47,800,000	$ 37,200,000
Debt instrument extended maturity date	Jun. 30, 2015