Quarterly Results of Operations (unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Quarterly Financial Information Disclosure [Abstract]
Revenues	$ 42,896	$ 43,814	$ 48,048	$ 41,861	$ 46,162	$ 51,025	$ 51,705	$ 42,467	$ 176,619	$ 191,359	$ 138,580
Gross profit	9,992	12,962	15,871	13,514	16,506	18,047	17,679	14,729	52,339	66,961	44,274
Net loss attributable to common stockholders	$ (10,716)	$ (778)	$ (155)	$ (1,235)	$ 2,360	$ 4,009	$ 3,154	$ 0	$ (12,884)	$ 9,523	$ 0
Net income (loss) per share, basic (in dollars per share)	$ (0.29)	$ (0.02)	$ 0.00	$ (0.03)	$ 0.06	$ 0.11	$ 0.13	$ 0.00	$ (0.35)	$ 0.38	$ 0.00
Net income (loss) per share, diluted (in dollars per share)	$ (0.29)	$ (0.02)	$ 0.00	$ (0.03)	$ 0.06	$ 0.10	$ 0.11	$ 0.00	$ (0.35)	$ 0.32	$ 0.00