Note 10 - Fair Value Measurement (Tables)

9 Months Ended

Sep. 30, 2019

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, 2019	Level 1		Level 2		Level 3		Total
Cash equivalents
Money market funds	$	68,579	$	—	$	—	$	68,579
Other noncurrent assets
Restricted cash		5,658		—		—		5,658
Total assets	$	74,237	$	—	$	—	$	74,237
Other current liabilities
Interest rate cash flow hedge	$	—	$	5,564	$	—	$	5,564
Total liabilities	$	—	$	5,564	$	—	$	5,564

December 31, 2018
Cash equivalents
Money market funds	$	84,613	$	—	$	—	$	84,613
Other noncurrent assets
Restricted cash		5,825		—		—		5,825
Total assets	$	90,438	$	—	$	—	$	90,438
Other current liabilities
Interest rate cash flow hedge	$	—	$	1,098	$	—	$	1,098
Total liabilities	$	—	$	1,098	$	—	$	1,098

September 30, 2018
Cash equivalents
Money market funds	$	68,765	$	—	$	—	$	68,765
Other current assets
Interest rate cash flow hedge		—		1,500		—		1,500
Other noncurrent assets
Restricted cash		5,599		—		—		5,599
Total assets	$	74,364	$	1,500	$	—	$	75,864

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

		September 30, 2019				December 31, 2018				September 30, 2018
(in thousands)	Fair Value Hierarchy	Carrying Value		Fair Value		Carrying Value		Fair Value		Carrying Value		Fair Value
Assets:
Held-to-maturity marketable securities	Level 1	$	47,918	$	47,856	$	66,100	$	65,290	$	81,103	$	79,941
Liabilities (including current maturities):
2019 Notes1	Level 3	$	—	$	—	$	40,000	$	40,484	$	80,000	$	82,191
Credit Agreement - term loan1	Level 3		140,625		141,634		146,250		147,141		148,125		148,832
Credit Agreement - revolving credit facility1	Level 3		250,000		251,986		197,000		197,889		137,000		137,636
Convertible notes	Level 1		—		—		—		—		69,659		69,472