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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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EQUITY BASED COMPENSATION (Details) - $ / shares	9 Months Ended
EQUITY BASED COMPENSATION (Details) - $ / shares	Sep. 30, 2017	May 12, 2017	May 05, 2017	Apr. 26, 2017
EQUITY-BASED COMPENSATION
Vesting period	3 years
Share Price	$ 20.00
Minimum
EQUITY-BASED COMPENSATION
Equity options term	7 years
Maximum
EQUITY-BASED COMPENSATION
Equity options term	10 years
Class A common stock \| Over-allotment option
EQUITY-BASED COMPENSATION
Share Price		$ 14.00
Class A common stock \| IPO
EQUITY-BASED COMPENSATION
Share Price			$ 14.00	$ 14.00
2016 plan \| Maximum
EQUITY-BASED COMPENSATION
Equity options term	10 years
2016 plan \| Class A common stock
EQUITY-BASED COMPENSATION
Maximum number of shares	5,400,400
Rockwater Equity Plan \| Class A common stock
EQUITY-BASED COMPENSATION
Maximum number of shares	1,011,087
Phantom Equity Awards
EQUITY-BASED COMPENSATION
Cash payment (per phantom unit)			$ 5.53
Substitute Awards \| 2016 plan \| Class A common stock
EQUITY-BASED COMPENSATION
Maximum number of shares	2,887,048