LEASES - Capitol Petroleum Group - Additional Information (Detail)	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Leases [Line Items]
Lease revenue percentage	16.00%	10.00%
White Oak Petroleum Realty LLC [Member]
Leases [Line Items]
Number of leased properties	37
Subsidiaries Of Capital Petroleum Group, LLC [Member]
Leases [Line Items]
Number of unitary leases	4
Subsidiaries Of Capital Petroleum Group, LLC [Member] | Gasoline Station and Convenience Store Properties [Member]
Leases [Line Items]
Number of leased properties	97
Hudson Petroleum [Member]
Leases [Line Items]
Number of leased properties	24
Big Apple Petroleum [Member]
Leases [Line Items]
Number of leased properties	16
Dogwood Petroleum [Member]
Leases [Line Items]
Number of leased properties	20