Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Consolidated Balance Sheets
Accounts receivable, allowance for doubtful accounts	$ 3,725	$ 3,219
Common stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Common stock, shares authorized	1,600,000,000	1,600,000,000
Common stock, shares issued	150,578,451	64,024,557
Common stock, shares outstanding	150,529,151	64,024,557
Preferred stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Preferred stock, shares authorized	20,000,000	20,000,000
Preferred stock, shares issued	6,194,233	0
Preferred stock, shares outstanding	6,194,233	0
Common stock held in treasury at cost (in shares)	49,300	0