Note 14 - Restructuring Charges - Restructuring Activities (Details) - USD ($)	3 Months Ended			12 Months Ended		36 Months Ended
	Apr. 02, 2017	Jan. 01, 2017	Jan. 01, 2017	Dec. 30, 2018	Dec. 31, 2017	Dec. 30, 2018
Total restructuring charge	$ 7,300,000		$ 19,800,000
Employee Severance [Member] | The 2018 Restructuring Plan [Member]
Total restructuring charge				$ 10,816,000
Cost incurred				53,000
Balance				10,763,000		$ 10,763,000
Employee Severance [Member] | The 2016 Separate Restructuring Plan [Member]
Total restructuring charge						10,652,000
Cost incurred		$ 1,451,000		2,568,000	$ 6,633,000
Balance				0		0
Fixed Asset Impairment [Member] | The 2018 Restructuring Plan [Member]
Total restructuring charge				8,569,000
Cost incurred				8,569,000
Balance				0		0
Fixed Asset Impairment [Member] | The 2016 Separate Restructuring Plan [Member]
Total restructuring charge						11,319,000
Cost incurred		8,019,000		0	3,300,000
Balance				0		0
Lease Exit Costs [Member] | The 2016 Separate Restructuring Plan [Member]
Total restructuring charge						5,116,000
Cost incurred		$ 27,000		0	$ 5,089,000
Balance				0		0
Other Restructuring [Member] | The 2018 Restructuring Plan [Member]
Total restructuring charge				1,144,000
Cost incurred				0
Balance				$ 1,144,000		$ 1,144,000