Note 10 - Fair Value Measurements (Tables)

6 Months Ended

Jun. 30, 2017

Notes Tables

Fair Value, Assets Measured on Recurring Basis [Table Text Block]

		June 30, 2017
	Fair Value Hierarchy	Cost		Unrealized Loss		Fair Value
Cash	Level 1	$	16,665	$	—	$	16,665
Agency	Level 1		4,495		—		4,495
Financial	Level 2		5,993		—		5,993
Industrial	Level 2		2,999		—		2,999
Total		$	30,152	$	—	$	30,152

		December 30, 2016
	Fair Value Hierarchy	Cost		Unrealized Loss			Fair Value
Cash	Level 1	$	33,821	$	—		$	33,821
Government	Level 1		2,005		—			2,005
Financial	Level 2		8,064		(1	)		8,063
Industrial	Level 2		11,125		(1	)		11,124
Total		$	55,015	$	(2	)	$	55,013

Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Table Text Block]

Risk-free interest rate	2.16	%
Expected volatility	55.00	%
Contractual term (in years)	10
Dividend yield	—	%