Note 5 - Fair Value Measurements (Tables)

3 Months Ended

Mar. 31, 2017

Notes Tables

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

			Fair Value Measurements at Reporting Date Using
	March 31, 2017		Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
Cash equivalents:
Money market funds	$	68,415	$	-	$	68,415	$	-
Bank certificates of deposit		2,000		-		2,000		-
Total cash equivalents	$	70,415	$	-	$	70,415	$	-
Investments:
Bank certificates of deposit	$	19,250	$	-	$	19,250	$	-

			Fair Value Measurements at Reporting Date Using
	December 31, 2016		Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
Cash equivalents:
Money market funds	$	68,352	$	-	$	68,352	$	-
Bank certificates of deposit		750		-		750		-
Total cash equivalents	$	69,102	$	-	$	69,102	$	-
Investments:
Bank certificates of deposit	$	20,500	$	-	$	20,500	$	-