Note 10 - Fair Value Measurement (Tables)

3 Months Ended

Mar. 31, 2022

Notes Tables

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

	Fair Value Measurement at Reporting Date Using
March 31, 2022	Level 1		Level 2		Level 3		Total
Cash equivalents
Money market funds	$	21,237	$	—	$	—	$	21,237
Other current assets
Commodity swap		—		3,047		—		3,047
Total assets	$	21,237	$	3,047	$	—	$	24,284
Accrued and other current liabilities
Interest rate swap	$	—	$	507	$	—	$	507
Total liabilities	$	—	$	507	$	—	$	507

December 31, 2021
Cash equivalents
Money market funds	$	65,233	$	—	$	—	$	65,233
Total assets	$	65,233	$	—	$	—	$	65,233
Accrued and other current liabilities
Interest rate swap	$	—	$	3,514	$	—	$	3,514
Total liabilities	$	—	$	3,514	$	—	$	3,514

March 31, 2021
Cash equivalents
Money market funds	$	42,488	$	—	$	—	$	42,488
Other current assets
Commodity swap		—		1,106		—		1,106
Total assets	$	42,488	$	1,106	$	—	$	43,594
Accrued and other current liabilities
Interest rate swap	$	—	$	6,535	$	—	$	6,535
Total liabilities	$	—	$	6,535	$	—	$	6,535

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

		March 31, 2022				December 31, 2021				March 31, 2021
(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	$	36,728	$	35,909	$	15,600	$	15,459	$	11,300	$	11,258
Liabilities (including current maturities):
2.75% Convertible Notes (2),(3)	Level 2	$	230,000	$	276,288	$	207,354	$	313,785	$	202,018	$	324,013
Credit Agreement - term loan (2)	Level 3	$	60,938	$	62,861	$	123,750	$	124,598	$	129,375	$	130,645