Note 11 - Commitments and Contingencies (Details Textual) $ in Millions	12 Months Ended
Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)
Operating Leases, Rent Expense	$ 8.7	$ 8.2	$ 7.5
Entity Number of Employees	305
Collective Bargaining Arrangements	9

Amount of rent expense incurred for leased assets, including but not limited to, furniture and equipment, that is not directly or indirectly associated with the manufacture, sale or creation of a product or product line.

No definition available.

Name:	us-gaap_LeaseAndRentalExpense
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration