Note 8 - Fair Value Measurement (Tables)

12 Months Ended

Dec. 31, 2020

Notes Tables

Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block]

	Fair Value Measurement at Reporting Date Using
December 31, 2020	Level 1		Level 2		Level 3		Total
Cash equivalents
Money market funds	$	70,483	$	—	$	—	$	70,483
Other noncurrent assets
Restricted cash		1,512		—		—		1,512
Total assets	$	71,995	$	—	$	—	$	71,995
Accrued and other current liabilities
Interest rate swap	$	—	$	7,606	$	—	$	7,606
Total liabilities	$	—	$	7,606	$	—	$	7,606
December 31, 2019
Cash equivalents
Money market funds	$	94,696	$	—	$	—	$	94,696
Other noncurrent assets
Restricted cash		5,835		—		—		5,835
Total assets	$	100,531	$	—	$	—	$	100,531
Accrued and other current liabilities
Interest rate swap	$	—	$	4,603	$	—	$	4,603
Total liabilities	$	—	$	4,603	$	—	$	4,603

Fair Value, by Balance Sheet Grouping [Table Text Block]

December 31,		2020				2019
	Fair Value Hierarchy	Carrying Value		Fair Value		Carrying Value		Fair Value
Assets:
Held-to-maturity marketable securities (1)	Level 1	$	5,200	$	5,200	$	32,799	$	32,792
Liabilities (including current maturities):
Credit Agreement - term loan (2)	Level 3		131,250		133,030		138,750		139,042
Credit Agreement - revolving credit facility (2)	Level 3		—		—		25,000		25,043
2.75% Convertible Notes (2),(3)	Level 2		200,303		248,400		193,696		249,895