Land and Subsurface Interests - Summary of Lease Payments on the Respective Acreages and Drilling Penalties Received (Detail)	3 Months Ended
	Mar. 31, 2016 USD ($) a
Real Estate Properties [Line Items]
Lease Payment, Received	$ 8,213,755
Drilling Penalty, Received	$ 1,775,000
Lease Year 1 - 9/23/2011 - 9/22/2012 [Member] | Lee and Hendry County Florida [Member]
Real Estate Properties [Line Items]
Oil exploration lease covering area | a	136,000
Lease Payment, Received	$ 913,657
Lease Year 2 - 9/23/2012 - 9/22/2013 [Member] | Lee and Hendry County Florida [Member]
Real Estate Properties [Line Items]
Oil exploration lease covering area | a	136,000
Lease Payment, Received	$ 922,114
Lease Year 3 - 9/23/2013 - 9/22/2014 [Member] | Hendry County Florida
Real Estate Properties [Line Items]
Oil exploration lease covering area | a	82,000
Lease Payment, Received	$ 3,293,000
Drilling Penalty, Received	$ 1,000,000
Lease Year 4 - 9/23/2014 - 9/22/2015 [Member] | Hendry County Florida
Real Estate Properties [Line Items]
Oil exploration lease covering area | a	42,000
Lease Payment, Received	$ 1,866,146
Drilling Penalty, Received	$ 600,000
Lease Year 5 - 9/23/2015 - 9/22/2016 [Member] | Hendry County Florida
Real Estate Properties [Line Items]
Oil exploration lease covering area | a	25,000
Lease Payment, Received	$ 1,218,838
Drilling Penalty, Received	$ 175,000