LONG-TERM DEBT (Details) (USD $)	3 Months Ended
	Mar. 31, 2013	Nov. 15, 2011
Maturities of Borrowings Under New Credit Facility
Thereafter	$ 71,800,000
Total	71,800,000
New Credit Facility
Long-term debt
Maximum borrowing capacity	100,000,000	60,000,000
Reduction in maximum borrowing capacity per quarter (as a percent)	1.50%
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
Outstanding amount	71,800,000
Variable interest rate base	LIBOR
Percentage points added to the reference rate	2.25%
One-month LIBOR interest rate (as a percent)	0.20%
New Credit Facility | Actual
Long-term debt
Leverage ratio	1.7
Fixed charge coverage ratio	10.1
New Credit Facility | Minimum
Long-term debt
Amount in which the maximum borrowing capacity may be permanently reduced	$ 500,000
New Credit Facility | Minimum | Requirement
Long-term debt
Fixed charge coverage ratio	1.15
New Credit Facility | Maximum | Requirement
Long-term debt
Leverage ratio	3.0