Offering Costs and Formation Transaction Expenses - Effect of Correction on Combined Financial Statements (Detail) (USD $)	3 Months Ended		12 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Dec. 31, 2012
Organization And Offering Costs [Line Items]
Formation transaction expenses	$ 201,235	$ 26,593
Net loss	(768,744)	(130,808)	3,736,707
Net cash provided by operating activities	250,520	395,471
Net cash used in financing activities	(1,447,005)	(2,418,486)
Net change in cash and cash equivalents	(1,196,485)	(2,023,015)
As reported [Member]
Organization And Offering Costs [Line Items]
Formation transaction expenses
Net loss		(104,215)
Net cash provided by operating activities		422,064
Net cash used in financing activities		(2,445,079)
Net change in cash and cash equivalents		(2,023,015)
Adjustment [Member]
Organization And Offering Costs [Line Items]
Formation transaction expenses		26,593
Net loss		(26,593)
Net cash provided by operating activities		(26,593)
Net cash used in financing activities		26,593
Net change in cash and cash equivalents
As adjusted [Member]
Organization And Offering Costs [Line Items]
Formation transaction expenses		26,593
Net loss		(130,808)
Net cash provided by operating activities		395,471
Net cash used in financing activities		(2,418,486)
Net change in cash and cash equivalents		$ (2,023,015)