Unaudited Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	Sep. 30, 2018	Dec. 31, 2017
Class A Units
Shareholders'/members' equity (deficit):
Capital units (in units)	0	6,374,000
Class B Units
Shareholders'/members' equity (deficit):
Capital units (in units)	0	3,506,000
Class C Units
Shareholders'/members' equity (deficit):
Capital units (in units)	0	375,000
Class D Units
Shareholders'/members' equity (deficit):
Capital units (in units)	0	1,104,000
Class E Units
Shareholders'/members' equity (deficit):
Capital units (in units)	0	1,012,000
Class A Common Stock
Shareholders'/members' equity (deficit):
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock shares authorized (in shares)	200,000,000	0
Common stock shares issued (in shares)	25,370,797	0
Common stock shares outstanding (in shares)	25,370,797	0
Class B Common Stock
Shareholders'/members' equity (deficit):
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock shares authorized (in shares)	40,000,000	0
Common stock shares issued (in shares)	35,913,538	0
Common stock shares outstanding (in shares)	35,913,538	0
Class C Common Stock
Shareholders'/members' equity (deficit):
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock shares authorized (in shares)	4,000,000	0
Common stock shares issued (in shares)	2,560,955	0
Common stock shares outstanding (in shares)	2,560,955	0
Class D Common Stock
Shareholders'/members' equity (deficit):
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock shares authorized (in shares)	32,000,000	0
Common stock shares issued (in shares)	17,282,930	0
Common stock shares outstanding (in shares)	17,282,930	0