| Related-Party Transactions - Summary of Management Fees, Incentive Fees and Associated Credits and Administration Fees (Parenthetical) (Detail) (USD $) | 3 Months Ended | 6 Months Ended | 9 Months Ended | |||
|---|---|---|---|---|---|---|
| Sep. 30, 2013 | Mar. 31, 2013 | Sep. 30, 2012 | Sep. 30, 2013 | Sep. 30, 2013 | Sep. 30, 2012 | |
| Related Party Transactions [Abstract] | ||||||
| Incentive fee paid to adviser | $ 0 | $ 41,037 | $ 0 | $ 0 | $ 41,037 | $ 0 | 
| X | ||||||||||
| 
- Definition Related party transaction incentive fee. No definition available. 
 | 
| X | ||||||||||
| 
- Details 
 |