Note 9 - Long-term Debt (Detail) - Credit Facility, Unused Fee Schedule (Revolver [Member], USD $)	12 Months Ended
Dec. 31, 2012
Minimum [Member]
Average Used Portion of the Revolver plus Outstanding Letters of Credit (in Dollars)	$ 60,000,000
Applicable Unused Revolver Fee Margin	0.375%
Maximum [Member]
Average Used Portion of the Revolver plus Outstanding Letters of Credit (in Dollars)	$ 60,000,000
Applicable Unused Revolver Fee Margin	0.50%

The fee, expressed as a percentage of the line of credit facility, for available but unused credit capacity under the credit facility.

No definition available.

Name:	us-gaap_LineOfCreditFacilityUnusedCapacityCommitmentFeePercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration