Note 6 - Credit Facilities and Capital Leases (Detail) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Oct. 31, 2009
Long-term Line of Credit			$ 60,000,000
Amortization of Deferred Charges	500,000
Interest Expense, Debt	1,000,000
Capital Leases Including Purchase Option	17,500,000
Capital Lease Obligations, Current	5,564,000	4,005,000
Capital Lease Obligations, Noncurrent	11,935,000	6,265,000
Capital Lease Obligations	17,499,000	10,300,000
LIBOR [Member] | Minimum [Member]
Debt Instrument, Basis Spread on Variable Rate	3.00%
LIBOR [Member] | Maximum [Member]
Debt Instrument, Basis Spread on Variable Rate	3.75%
Alternative Base Rate [Member] | Minimum [Member]
Debt Instrument, Basis Spread on Variable Rate	2.00%
Alternative Base Rate [Member] | Maximum [Member]
Debt Instrument, Basis Spread on Variable Rate	2.75%
Minimum [Member]
Standby Fee Percentage	0.825%
Maximum [Member]
Standby Fee Percentage	1.05%
Senior Secured Revolving Credit Facility [Member]
Line of Credit Facility, Maximum Borrowing Capacity	$ 150,000,000