Note 6 - Long-term Obligations - Summary of Long-term Obligations (Details) - USD ($)	Sep. 30, 2017	Mar. 28, 2017	Dec. 31, 2016
Total debt	$ 187,665,000		$ 179,599,000
Less current portion	(17,251,000)		(1,973,000)
Long-term obligations, net of current portion	170,414,000		177,626,000
The 2017 Senior Credit Facility [Member]
Long-term obligations	180,000,000
Debt discount	(2,834,000)	$ (3,172,000)
Debt issuance costs	(3,047,000)
The 2015 Senior Secured Credit Facilities Due 2018 [Member]
Long-term obligations			86,750,000
Debt issuance costs			(1,738,000)
6.25% Convertible Notes Due 2018 [Member]
Debt discount	(74,000)		(2,271,000)
Debt issuance costs	(16,000)		(467,000)
Convertible notes	10,044,000	$ 94,000,000	94,000,000
Capital leases and other long-term obligations	3,592,000		3,325,000
Total debt	$ 9,970,000		$ 91,729,000