Derivative Instruments - Cash Flow Hedge of Interest Rate Risk - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Ineffective portion of change in fair value of derivatives instruments recognized in earnings	$ 0	$ 0
Interest expense	18,826,701	17,813,762	11,859,146
Fair value of derivatives in a net liability position	310,000
Termination value in case of breach of provisions	310,000
Interest Rate Swap
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Number of instruments	1
Reclassification from AOCI to Interest Expense
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Interest expense	$ 303,000