Note 4 - Revenue Recognition - Contract Assets and Liabilities (Details) - USD ($) $ in Thousands		Dec. 31, 2019	Dec. 31, 2018	[1]	Jan. 01, 2018
Contract assets, included in accounts receivable		$ 1,067	$ 798		$ 505
Contract liabilities, included in Deferred revenue - short-term		5,030	4,374
Contract liabilities, included in Deferred revenue - long-term		17,151	15,959
Trade Accounts Receivable [Member]
Trade receivables, included in accounts receivable, net of allowances for bad debts of $0**	[2]	$ 11,902	$ 15,496

[1] Contract asset and contract liability balances at January 1, 2018 were $505 and $21,013, respectively.

[2] Exclusive of the BTC of $97,295 and $0, respectively, and net of allowances for bad debt of $0 as of the dates noted.