Note 3 - Fair Value Measurements (Tables)

3 Months Ended

Mar. 31, 2021

Notes Tables

Schedule of Derivative Assets at Fair Value [Table Text Block]

	March 31, 2021		December 31, 2020
Assets:
Derivatives instruments - open contracts, current	$	2,691	$	2,705
Derivatives instruments - open contracts, long-term		1,731		2,762
Liabilities:
Derivatives instruments - open contracts, current		29,227		13,291
Derivatives instruments - open contracts, long-term		3,514		4,384

Schedule of Carrying Values and Estimated Fair Values of Debt Instruments [Table Text Block]

	March 31, 2021				December 31, 2020
	Net Value		Fair Value		Net Value		Fair Value
Liabilities:
Credit Agreement	$	48,000	$	48,000	$	80,000	$	80,000
Senior Second Lien Notes		545,838		490,087		545,286		393,352
Total		593,838		538,087		625,286		473,352