INCOME TAXES (Details) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012 M	Jun. 30, 2011
INCOME TAXES
State tax, low end of range of rate (as a percent)			6.00%
State tax, high end of range of rate (as a percent)			6.50%
Decrease in valuation allowance (in dollars)	$ 8,000,000
Period of adjusted historical income for evaluating valuation allowance (in months)			24
Fuel tax credit (in dollars)				500,000
Refund of federal and state taxes paid in prior years (in dollars)			2,600,000
State and foreign income taxes paid (in dollars)			400,000
Reconciliation between the effective income tax rate, as computed on loss before income taxes, and the statutory federal income tax rate
Income tax benefit at the statutory federal rate			(5,758,000)
Federal income tax effects of:
Increase in valuation allowances for the prior quarter			4,640,000
Reversal of valuation allowances for the current quarter			(7,973,000)
Effect of permanent differences and other			(871,000)
State income taxes			(169,000)
Total provision (benefit) for income taxes	$ (5,757,000)	$ 3,169,000	$ (10,131,000)	$ (4,177,000)
Income tax benefit at the statutory federal rate (as a percent)			(35.00%)
Federal income tax effects of:
Increase in valuation allowances for the prior quarter (as a percent)			28.20%
Reversal of valuation allowances for the current quarter (as a percent)			(48.50%)
Effect of permanent differences and other (as a percent)			(5.30%)
State income taxes (as a percent)			(1.00%)
Total provision (benefit) for income taxes (as a percent)			61.60%	36.30%