Note 10 - Long-term Obligations - Summary of Long-term Obligations (Details) - USD ($)	Dec. 31, 2017	Mar. 28, 2017	Dec. 31, 2016	Jan. 29, 2016	Sep. 14, 2015
Capital leases and other long-term obligations	$ 185,989,000		$ 179,599,000
Less current portion	(17,030,000)		(1,973,000)
Long-term obligations, net of current portion	168,959,000		177,626,000
The 2017 Senior Credit Facility [Member]
Long-term obligations	178,350,000
Debt discount	(2,668,000)	$ (3,172,000)
Debt issuance costs	(2,869,000)
The 2015 Senior Secured Credit Facilities Due 2018 [Member]
Long-term obligations			86,750,000		$ 90,000,000
Debt issuance costs			(1,738,000)
6.25% Convertible Notes Due 2018 [Member]
Debt discount	(18,000)		(2,271,000)	$ (250,000)
Debt issuance costs	(4,000)		(467,000)
Convertible notes	10,044,000	$ 94,000,000	94,000,000
Capital leases and other long-term obligations	$ 3,154,000		$ 3,325,000