INDEBTEDNESS - Additional Information (Details) - USD ($)		3 Months Ended		9 Months Ended
	Aug. 06, 2019	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Aug. 31, 2019	Dec. 31, 2018	Dec. 31, 2015
Debt Instrument [Line Items]
Original issue discount		$ 20,557,000		$ 20,557,000			$ 1,062,000
Debt issuance costs		38,045,000		38,045,000			11,076,000
Principal amount of debt		1,266,398,000		1,266,398,000			539,375,000
Payments to extinguish debt				2,075,000	$ 4,112,000
Proceeds from issuance of debt				981,050,000	1,000,000
Loss on extinguishment of debt				5,469,000	72,000
Fees incurred netted against proceeds				36,538,000	$ 0
Senior Notes
Debt Instrument [Line Items]
Loss on extinguishment of debt	$ 5,500,000
Credit Arrangements Administered By Bank Of America, N.A. | Senior Notes
Debt Instrument [Line Items]
Face amount of debt instruments								$ 645,000,000
Loss on extinguishment of debt	(2,300,000)
Credit Agreements, Entered Into 2019 | Senior Notes
Debt Instrument [Line Items]
Face amount of debt instruments	1,475,000,000
Debt issuance costs	54,600,000
Proceeds from issuance of debt				981,100,000
Debt issuance costs and third party fees	59,100,000
Issuance costs expensed	1,300,000
Fees incurred netted against proceeds				21,300,000
Deferred financing costs				36,500,000
Deferred financing costs, investing activities				1,300,000
Credit Arrangements, Entered Into 2015, Modified Loans | Senior Notes
Debt Instrument [Line Items]
Debt issuance costs	7,600,000
Revolving Credit Facility | Senior Notes
Debt Instrument [Line Items]
Original issue discount		0		0			0
Debt issuance costs		0		0			0
Principal amount of debt		0		0			$ 0
Revolving Credit Facility | Credit Agreements, Entered Into 2019 | Senior Notes
Debt Instrument [Line Items]
Face amount of debt instruments	150,000,000
Principal amount of debt		$ 0		0
Commitment fee percentage		2.50%
Net borrowing availability		$ 140,400,000		140,400,000
Revolving Credit Facility | Minimum | Credit Agreements, Entered Into 2019 | Senior Notes
Debt Instrument [Line Items]
Commitment fee, unused portion		0.25%
Revolving Credit Facility | Minimum | Credit Agreements, Entered Into 2019 | Senior Notes | Base Rate
Debt Instrument [Line Items]
Basis spread on variable rate		1.25%
Revolving Credit Facility | Minimum | Credit Agreements, Entered Into 2019 | Senior Notes | Eurocurrency Rate
Debt Instrument [Line Items]
Basis spread on variable rate		2.25%
Revolving Credit Facility | Maximum | Credit Agreements, Entered Into 2019 | Senior Notes
Debt Instrument [Line Items]
Commitment fee, unused portion		0.375%
Revolving Credit Facility | Maximum | Credit Agreements, Entered Into 2019 | Senior Notes | Base Rate
Debt Instrument [Line Items]
Basis spread on variable rate		1.75%
Revolving Credit Facility | Maximum | Credit Agreements, Entered Into 2019 | Senior Notes | Eurocurrency Rate
Debt Instrument [Line Items]
Basis spread on variable rate		2.75%
Letters of Credit | Credit Agreements, Entered Into 2019 | Senior Notes
Debt Instrument [Line Items]
Undrawn letters of credit issued and outstanding		$ 9,600,000		$ 9,600,000
First Lien Term Loan | Senior Notes
Debt Instrument [Line Items]
Principal amount of debt	575,000,000
First Lien Term Loan | Credit Arrangements Administered By Bank Of America, N.A. | Senior Notes
Debt Instrument [Line Items]
Face amount of debt instruments								415,000,000
Original issue discount						$ 900,000		2,100,000
Debt issuance costs						4,700,000		21,100,000
Outstanding balance of debt repaid						393,800,000
Principal amount of debt						399,400,000
Effective rate on term loans at end of period							6.10%
Weighted average interest rate paid on term loans during period		6.06%	5.83%	6.20%	6.38%
First Lien Term Loan | Credit Agreements, Entered Into 2019 | Senior Notes
Debt Instrument [Line Items]
Face amount of debt instruments	925,000,000
Effective rate on term loans at end of period		6.61%		6.61%
Weighted average interest rate paid on term loans during period		6.67%
Quarterly installment payments		$ 2,300,000
Payments to extinguish debt	226,700,000
Proceeds from issuance of debt	752,400,000
First Lien Term Loan | Minimum | Credit Agreements, Entered Into 2019 | Senior Notes | Base Rate
Debt Instrument [Line Items]
Basis spread on variable rate		3.25%
First Lien Term Loan | Minimum | Credit Agreements, Entered Into 2019 | Senior Notes | Eurocurrency Rate
Debt Instrument [Line Items]
Basis spread on variable rate		4.25%
First Lien Term Loan | Maximum | Credit Agreements, Entered Into 2019 | Senior Notes | Base Rate
Debt Instrument [Line Items]
Basis spread on variable rate		3.50%
First Lien Term Loan | Maximum | Credit Agreements, Entered Into 2019 | Senior Notes | Eurocurrency Rate
Debt Instrument [Line Items]
Basis spread on variable rate		4.50%
Second Lien Term Loan | Credit Arrangements Administered By Bank Of America, N.A. | Senior Notes
Debt Instrument [Line Items]
Face amount of debt instruments								150,000,000
Debt issuance costs						4,200,000
Outstanding balance of debt repaid						145,800,000
Principal amount of debt						$ 150,000,000
Effective rate on term loans at end of period							11.15%
Weighted average interest rate paid on term loans during period		11.02%	11.09%	11.36%	10.68%
Second Lien Term Loan | Credit Agreements, Entered Into 2019 | Senior Notes
Debt Instrument [Line Items]
Face amount of debt instruments	400,000,000
Effective rate on term loans at end of period		10.89%		10.89%
Weighted average interest rate paid on term loans during period		10.89%
Payments to extinguish debt	0
Proceeds from issuance of debt	250,000,000
Loss on extinguishment of debt	$ 3,200,000
Second Lien Term Loan | Credit Agreements, Entered Into 2019 | Senior Notes | Base Rate
Debt Instrument [Line Items]
Basis spread on variable rate		1.00%
Second Lien Term Loan | Credit Agreements, Entered Into 2019 | Senior Notes | LIBOR
Debt Instrument [Line Items]
Basis spread on variable rate		8.75%
Bank Of America, N.A. | Revolving Credit Facility | Credit Arrangements Administered By Bank Of America, N.A. | Senior Notes
Debt Instrument [Line Items]
Face amount of debt instruments								$ 80,000,000