Note 9 - Fair Value Measurement (Tables)

9 Months Ended

Sep. 30, 2021

Notes Tables

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

	Fair Value Measurement at Reporting Date Using
September 30, 2021	Level 1		Level 2		Level 3		Total
Cash equivalents
Money market funds	$	61,231	$	—	$	—	$	61,231
Other noncurrent assets
Restricted cash		1,512		—		—		1,512
Total assets	$	62,743	$	—	$	—	$	62,743
Accrued and other current liabilities
Interest rate swap	$	—	$	5,001	$	—	$	5,001
Total liabilities	$	—	$	5,001	$	—	$	5,001

December 31, 2020
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

September 30, 2020
Cash equivalents
Money market funds	$	78,981	$	—	$	—	$	78,981
Other noncurrent assets
Restricted cash		1,512		—		—		1,512
Total assets	$	80,493	$	—	$	—	$	80,493
Accrued and other current liabilities
Interest rate swap	$	—	$	8,353	$	—	$	8,353
Total liabilities	$	—	$	8,353	$	—	$	8,353

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

		September 30, 2021				December 31, 2020				September 30, 2020
(in thousands)	Fair Value Hierarchy	Carrying Value		Fair Value		Carrying Value		Fair Value		Carrying Value		Fair Value
Assets:
Held-to-maturity marketable securities (1)	Level 1	$	10,600	$	10,582	$	5,200	$	5,200	$	5,700	$	5,696
Liabilities (including current maturities):
2.75% Convertible Notes (2),(3)	Level 2	$	205,543	$	326,025	$	200,303	$	248,400	$	198,606	$	184,000
Credit Agreement - term loan (2)	Level 3		125,625		126,610		131,250		133,030		133,125		135,046
Credit Agreement - revolving credit facility (2)	Level 3		—		—		—		—		75,000		76,180