Note 6 - Leases - Lease Expense (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Operating lease expense	[1]	$ 360	$ 267	$ 672	$ 503
Short-term lease expense		86	25	177	40
Land option expense		1	159	9	319
Total land option and lease expense		447	451	858	862
Cash flows from operating activities				461	367
Adoption of Topic 842				0	1,562
In exchange for new operating lease liabilities during the period				605	446
Office Leases [Member]
Operating lease expense		248	146	453	262
Land Leases [Member]
Operating lease expense		$ 112	$ 121	$ 219	$ 241

[1] Includes amortization of right-of-use assets for the three months ended March 31, 2020 and 2019 of $294 thousand and $184 thousand, respectively.