BUSINESS AND BASIS OF PRESENTATION (Details) $ / shares in Units, $ in Millions			6 Months Ended	12 Months Ended
	Apr. 26, 2017 shares	Dec. 20, 2016 $ / shares shares	Jun. 30, 2020 segment item $ / shares shares	Dec. 31, 2019 $ / shares shares	Nov. 01, 2017 USD ($)	Dec. 31, 2016 shares
Common units issued		16,100,000
Number of tax receivable agreements			2
Common shares exchanged			0
Number of cost-method investee | item			1
Number of operating segments | segment			3
Number of reportable segments | segment			3
Revolving line of credit
Maximum borrowing capacity | $					$ 300.0
Class A-1 Common Stock
Par value | $ / shares		$ 0.01
Class A-1 Common Stock | Private Placement
Shares issued		16,100,000
Conversion rate per share						1
Class A Common Stock
Par value | $ / shares		$ 0.01	$ 0.01	$ 0.01
Common stock issued			86,883,049	87,893,525
Common units exchanged				9,805,742
Common shares exchanged				9,805,742
Class A Common Stock | IPO
Shares issued	8,700,000
Class B Common Stock
Par value | $ / shares		$ 0.01	$ 0.01	$ 0.01
Common stock issued		38,462,541	16,221,101	16,221,101
Common Stock, Shares, Outstanding			16,221,101	16,221,101
Shares cancelled				9,805,742
Class A-2 Common Stock
Par value | $ / shares			$ 0.01	$ 0.01
Common stock issued			0	0
Common Stock, Shares, Outstanding			0	0