Note 11 - Asset Retirement Obligation (Tables)

6 Months Ended

12 Months Ended

Jun. 30, 2020

Dec. 31, 2019

Notes Tables

Schedule of Change in Asset Retirement Obligation [Table Text Block]

	2020		2019
Balance at January 1,	$	4,374	$	5,832
Accretion expense		187		211
Balance at June 30,	$	4,561	$	6,043

The following table summarizes changes in the Company’s ARO (in thousands):

	December 31,
	2019		2018
Balance, beginning of year	$	5,832	$	21,548
Accretion expense		422		1,271
Changes in estimates		(1,880)		(16,987)
Balance, end of year	$	4,374	$	5,832