LONG-TERM DEBT (Details)	3 Months Ended	6 Months Ended
	Jun. 30, 2015 USD ($)	Jun. 30, 2015 USD ($)	Jun. 30, 2013 USD ($)	Nov. 15, 2011 USD ($)
Long-term debt
Maximum borrowing capacity	$ 66,500,000	$ 66,500,000
Amount drawn under the facility		42,200,000
Amount in which the maximum borrowing capacity may be permanently reduced	20,000,000
Maturities of Borrowings Under New Credit Facility
2016	42,200,000	42,200,000
Total	$ 42,200,000	42,200,000
Credit Facility
Long-term debt
Maximum borrowing capacity				$ 100,000,000
Reduction in maximum borrowing capacity			$ 1,500,000
Multiple which may be used to permanently reduce the maximum borrowing capacity under the credit facility		$ 50,000
Maturities of Borrowings Under New Credit Facility
Variable interest rate base		LIBOR
Percentage points added to the reference rate		1.25%
One-month LIBOR interest rate (as a percent)	0.19%	0.19%
Credit Facility | Actual
Long-term debt
Leverage ratio		0.9
Fixed charge coverage ratio		32.00
Credit Facility | Minimum
Long-term debt
Amount in which the maximum borrowing capacity may be permanently reduced		$ 500,000
Credit Facility | Minimum | Requirement
Long-term debt
Fixed charge coverage ratio		1.15
Credit Facility | Maximum | Requirement
Long-term debt
Leverage ratio		2.0
Old Credit Facility
Long-term debt
Maximum borrowing capacity				$ 60,000,000