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	$ 104,814	$ 14,346
Net loss	(662,069)	(186,849)	1,967,456
Net cash provided by operating activities	99,485	244,712
Net cash used in financing activities	(895,499)	(615,433)
Net change in cash and cash equivalents	(796,014)	(353,737)
As reported [Member]
Organization And Offering Costs [Line Items]
Net loss		(172,503)
Net cash provided by operating activities		259,058
Net cash used in financing activities		(629,779)
Net change in cash and cash equivalents		1,971,287
Adjustment [Member]
Organization And Offering Costs [Line Items]
Formation transaction expenses		14,346
Net loss		(14,346)
Net cash provided by operating activities		(14,346)
Net cash used in financing activities		14,346
As adjusted [Member]
Organization And Offering Costs [Line Items]
Formation transaction expenses		14,346
Net loss		(186,849)
Net cash provided by operating activities		244,712
Net cash used in financing activities		(615,433)
Net change in cash and cash equivalents		$ 1,971,287