Offering Costs and Formation Transaction Expenses - Effect of Correction on Combined Financial Statements (Detail) (USD $)	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012	Dec. 31, 2012
Organization And Offering Costs [Line Items]
Formation transaction expenses	$ 132,363	$ 56,229	$ 333,598	$ 82,822
Net loss	(935,849)	(371,876)	(1,704,593)	(502,684)	3,736,707
Net cash provided by operating activities			76,762	1,047,587
Net cash used in financing activities			1,669,783	(3,690,570)
Net change in cash and cash equivalents			(800,640)	(3,590,915)
As Reported [Member]
Organization And Offering Costs [Line Items]
Formation transaction expenses
Net loss				(419,862)
Net cash provided by operating activities				1,130,409
Net cash used in financing activities				(3,773,392)
Net change in cash and cash equivalents				(3,590,915)
Adjustment [Member]
Organization And Offering Costs [Line Items]
Formation transaction expenses				82,822
Net loss				(82,822)
Net cash provided by operating activities				(82,822)
Net cash used in financing activities				82,822
Net change in cash and cash equivalents
As Adjusted [Member]
Organization And Offering Costs [Line Items]
Formation transaction expenses				82,822
Net loss				(502,684)
Net cash provided by operating activities				1,047,587
Net cash used in financing activities				(3,690,570)
Net change in cash and cash equivalents				$ (3,590,915)