Note 9 - Fair Value Measurement (Tables)

6 Months Ended

Jun. 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
June 30, 2021	Level 1		Level 2		Level 3		Total
Cash equivalents
Money market funds	$	23,489	$	—	$	—	$	23,489
Other current assets
Commodity swap		—		1,550		—		1,550
Other noncurrent assets
Restricted cash		1,512		—		—		1,512
Total assets	$	25,001	$	1,550	$	—	$	26,551
Accrued and other current liabilities
Interest rate swap	$	—	$	5,770	$	—	$	5,770
Total liabilities	$	—	$	5,770	$	—	$	5,770

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

June 30, 2020
Cash equivalents
Money market funds	$	104,704	$	—	$	—	$	104,704
Other current assets
Commodity swap		—		598		—		598
Other noncurrent assets
Restricted cash		1,512		—		—		1,512
Total assets	$	106,216	$	598	$	—	$	106,814
Accrued and other current liabilities
Interest rate swap	$	—	$	9,058	$	—	$	9,058
Total liabilities	$	—	$	9,058	$	—	$	9,058

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

		June 30, 2021				December 31, 2020				June 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	$	10,850	$	10,801	$	5,200	$	5,200	$	5,896	$	5,896
Liabilities (including current maturities):
2.75% Convertible Notes (2),(3)	Level 2	$	203,771	$	333,500	$	200,303	$	248,400	$	196,946	$	184,554
Credit Agreement - term loan (2)	Level 3		127,500		128,639		131,250		133,030		135,000		137,116
Credit Agreement - revolving credit facility (2)	Level 3		—		—		—		—		75,000		76,291