Note 9 - Financial Instruments and Fair Value (Tables)

12 Months Ended

Dec. 31, 2017

Notes Tables

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

At December 31, 201 7

At December 31, 201 6

Level 1 Inputs

Level 2 Inputs

Level 3 Inputs

Level 1 Inputs

Level 2 Inputs

Level 3 Inputs

Investment in auction rate securities

$

─

$

─

$

6,375

$

─

$

─

$

6,231

Schedule of Available-for-sale Securities Reconciliation [Table Text Block]

	C ost Basis Amount		Gross Unrealized Loss In Accumulated OCI		Fair Value
December 31, 201 7
Investment in auction rate securities	$	6,375	$	-	$	6,375
December 31, 201 6
Investment in auction rate securities	$	6,700	$	469	$	6,231

Schedule of Derivative Instruments, Effect on Other Comprehensive Income (Loss) [Table Text Block]

Description	Fair Value Measurements Using Significant Unobservable Inputs December 31 , 201 7		Loss D uring the Year Ended December 31, 2017		Loss D uring the Year Ended December 31, 2016
Long-lived assets held for sale	$	9,505	$	−	$	(7,481	)