Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Current assets:
Allowance for uncollectible accounts	$ 1,512	$ 272
Capitalization:
Common stock, par value	$ 0.001	$ 0.001
Common stock, shares authorized	70,000,000	36,000,000
Common stock, shares issued	28,456,508	28,404,316
Common stock, shares outstanding	28,456,508	28,404,316