Consolidated Balance Sheets (Parentheticals) - USD ($) $ in Thousands	Dec. 31, 2019	Jul. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Statement of Financial Position [Abstract]
Allowance for accounts receivable	$ 4,654		$ 7,562	$ 4,404	$ 1,940
Common stock, par value (in dollars per share)	$ 0.0001		$ 0.0001
Common stock, authorized (in shares)	250,000,000		250,000,000
Common stock, issued (in shares)	49,033,903	49,033,903	21,660,638
Common stock, outstanding (in shares)	49,033,903	49,033,903	21,660,638