Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Trade accounts receivable, allowance for doubtful accounts	$ 500	$ 905
Receivable from customers, allowance	$ 327	$ 666
Convertible preferred stock, shares issued	0
Convertible preferred stock, shares outstanding	0
Preferred stock, par value	$ 0.0001	$ 0.0001
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Preferred stock, shares authorized	20,000,000
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, shares, issued	66,490,000	5,992,000
Common stock, shares, outstanding	66,490,156	5,992,000
Common stock, shares authorized	600,000,000	153,945,000
Series A Convertible Preferred Stock
Convertible preferred stock, par value	$ 0.0001	$ 0.0001
Convertible preferred stock, shares issued	0	12,309,000
Convertible preferred stock, shares outstanding	0	12,309,000
Convertible preferred stock, shares authorized		13,814,000
Convertible preferred stock, aggregate liquidation preference		$ 10,930
Series A-1 Convertible Preferred Stock
Convertible preferred stock, par value	$ 0.0001	$ 0.0001
Convertible preferred stock, shares issued	0	4,688,000
Convertible preferred stock, shares outstanding	0	4,688,000
Convertible preferred stock, shares authorized		5,012,000
Convertible preferred stock, aggregate liquidation preference		$ 2,081
Series A-2 Convertible Preferred Stock
Convertible preferred stock, par value	$ 0.0001	$ 0.0001
Convertible preferred stock, shares issued	0	279,000
Convertible preferred stock, shares outstanding	0	279,000
Convertible preferred stock, shares authorized		279,000
Convertible preferred stock, aggregate liquidation preference		$ 472
Series B Convertible Preferred Stock
Convertible preferred stock, par value	$ 0.0001	$ 0.0001
Convertible preferred stock, shares issued	0	1,793,000
Convertible preferred stock, shares outstanding	0	1,793,000
Convertible preferred stock, shares authorized		2,133,000
Convertible preferred stock, aggregate liquidation preference		$ 1,685
Series B-1 Convertible Preferred Stock
Convertible preferred stock, par value	$ 0.0001	$ 0.0001
Convertible preferred stock, shares issued	0	21,518,000
Convertible preferred stock, shares outstanding	0	21,518,000
Convertible preferred stock, shares authorized		21,600,000
Convertible preferred stock, aggregate liquidation preference		$ 23,670
Series C Convertible Preferred Stock
Convertible preferred stock, par value	$ 0.0001	$ 0.0001
Convertible preferred stock, shares issued	0	7,069,000
Convertible preferred stock, shares outstanding	0	7,069,000
Convertible preferred stock, shares authorized		7,069,000
Convertible preferred stock, aggregate liquidation preference		$ 20,000
Series C-1 Convertible Preferred Stock
Convertible preferred stock, par value	$ 0.0001	$ 0.0001
Convertible preferred stock, shares issued	0	8,511,000
Convertible preferred stock, shares outstanding	0	8,511,000
Convertible preferred stock, shares authorized		8,590,000
Convertible preferred stock, aggregate liquidation preference		$ 12,767
Series D Convertible Preferred Stock
Convertible preferred stock, par value	$ 0.0001	$ 0.0001
Convertible preferred stock, shares issued	0	8,566,000
Convertible preferred stock, shares outstanding	0	8,566,000
Convertible preferred stock, shares authorized		10,172,000
Convertible preferred stock, aggregate liquidation preference		$ 44,972
Series D-1 Convertible Preferred Stock
Convertible preferred stock, par value	$ 0.0001	$ 0.0001
Convertible preferred stock, shares issued	0	22,808,000
Convertible preferred stock, shares outstanding	0	22,808,000
Convertible preferred stock, shares authorized		22,862,000
Convertible preferred stock, aggregate liquidation preference		$ 144,147
Series D-2 Convertible Preferred Stock
Convertible preferred stock, par value	$ 0.0001	$ 0.0001
Convertible preferred stock, shares issued	0	14,245,000
Convertible preferred stock, shares outstanding	0	14,245,000
Convertible preferred stock, shares authorized		14,815,000
Convertible preferred stock, aggregate liquidation preference		$ 96,154