Note 6 - Deferred Revenue (Tables)

9 Months Ended

Sep. 30, 2020

Notes Tables

Contract with Customer, Contract Asset, Contract Liability, and Receivable [Table Text Block]

	Three Months Ended September 30,						Nine Months Ended September 30,
	2020			2019			2020			2019
Beginning Balance	$	11,779		$	13,859		$	14,222		$	11,855
Add: Payments Received		3,854			3,624			9,314			13,075
Less: Revenue		(3,809	)		(4,010	)		(11,712	)		(11,457	)
Ending Balance	$	11,824		$	13,473		$	11,824		$	13,473