FINANCING ARRANGEMENTS - Summary of Consolidated Long-term Debt (Details) - USD ($)	Sep. 30, 2019	May 23, 2019	Mar. 08, 2019	Dec. 31, 2018	Jun. 01, 2018	Mar. 26, 2018
Long-term debt, net of unamortized debt discount
Principal Amount	$ 23,841,000,000			$ 24,632,000,000
Total long-term debt and other	23,566,000,000			24,305,000,000
Less: Current portion of long-term debt and other	100,000,000			228,000,000
Non-current portion of long-term debt	23,466,000,000			24,077,000,000
Term Loan B Facility Due June 2025
Long-term debt, net of unamortized debt discount
Principal Amount	3,932,000,000			4,394,000,000
Total long-term debt and other	3,826,000,000			4,269,000,000
Term Loan B Facility Due November 2025
Long-term debt, net of unamortized debt discount
Principal Amount	$ 1,312,000,000			1,481,000,000
Stated interest rate on debt (as a percent)	4.79%
Total long-term debt and other	$ 1,293,000,000			1,456,000,000
Senior Secured Notes | 6.50% Senior Secured Notes Due March 2022
Long-term debt, net of unamortized debt discount
Principal Amount	$ 1,250,000,000			1,250,000,000
Stated interest rate on debt (as a percent)	6.50%
Total long-term debt and other	$ 1,241,000,000			1,239,000,000
Senior Secured Notes | 7.00% Senior Secured Notes Due March 2024
Long-term debt, net of unamortized debt discount
Principal Amount	$ 2,000,000,000			2,000,000,000
Stated interest rate on debt (as a percent)	7.00%
Total long-term debt and other	$ 1,982,000,000			1,979,000,000
Senior Secured Notes | 5.50% Senior Secured Notes Due November 2025
Long-term debt, net of unamortized debt discount
Principal Amount	$ 1,750,000,000			1,750,000,000
Stated interest rate on debt (as a percent)	5.50%
Total long-term debt and other	$ 1,732,000,000			1,730,000,000
Senior Secured Notes | 5.75% Senior Secured Notes Due August 2027
Long-term debt, net of unamortized debt discount
Principal Amount	$ 500,000,000			0
Stated interest rate on debt (as a percent)	5.75%
Total long-term debt and other	$ 493,000,000			0
Senior Unsecured Notes | 5.625% Senior Notes Due December 2021
Long-term debt, net of unamortized debt discount
Principal Amount	$ 0			700,000,000
Stated interest rate on debt (as a percent)	5.625%		5.625%
Total long-term debt and other	$ 0			697,000,000
Senior Unsecured Notes | 5.50% Senior Notes Due March 2023
Long-term debt, net of unamortized debt discount
Principal Amount	$ 402,000,000			1,000,000,000
Stated interest rate on debt (as a percent)	5.50%		5.50%
Total long-term debt and other	$ 400,000,000			995,000,000
Senior Unsecured Notes | 5.875% Senior Notes Due May 2023
Long-term debt, net of unamortized debt discount
Principal Amount	$ 1,548,000,000			3,250,000,000
Stated interest rate on debt (as a percent)	5.875%		5.875%
Total long-term debt and other	$ 1,540,000,000			3,229,000,000
Senior Unsecured Notes | 4.50% Senior Notes euro-denoted debt Due May 2023
Long-term debt, net of unamortized debt discount
Principal Amount	$ 1,635,000,000			1,720,000,000
Stated interest rate on debt (as a percent)	4.50%
Total long-term debt and other	$ 1,626,000,000			1,709,000,000
Senior Unsecured Notes | 6.125% Senior Notes Due April 2025
Long-term debt, net of unamortized debt discount
Principal Amount	$ 3,250,000,000			3,250,000,000
Stated interest rate on debt (as a percent)	6.125%
Total long-term debt and other	$ 3,229,000,000			3,226,000,000
Senior Unsecured Notes | 9.00% Senior Notes Due December 2025
Long-term debt, net of unamortized debt discount
Principal Amount	$ 1,500,000,000			1,500,000,000
Stated interest rate on debt (as a percent)	9.00%
Total long-term debt and other	$ 1,472,000,000			1,469,000,000
Senior Unsecured Notes | 9.25% Senior Notes Due April 2026
Long-term debt, net of unamortized debt discount
Principal Amount	$ 1,500,000,000			1,500,000,000
Stated interest rate on debt (as a percent)	9.25%					9.25%
Total long-term debt and other	$ 1,484,000,000			1,482,000,000
Senior Unsecured Notes | 8.50% Senior Notes Due January 2027
Long-term debt, net of unamortized debt discount
Principal Amount	$ 1,750,000,000			750,000,000
Stated interest rate on debt (as a percent)	8.50%				8.50%
Total long-term debt and other	$ 1,756,000,000			738,000,000
Senior Unsecured Notes | 7.00 % Senior Notes Due January 2028
Long-term debt, net of unamortized debt discount
Principal Amount	$ 750,000,000			0
Stated interest rate on debt (as a percent)	7.00%	7.00%
Total long-term debt and other	$ 740,000,000			0
Senior Unsecured Notes | 7.25 % Senior Notes Due May 2029
Long-term debt, net of unamortized debt discount
Principal Amount	$ 750,000,000			0
Stated interest rate on debt (as a percent)	7.25%	7.25%
Total long-term debt and other	$ 740,000,000			0
Senior Unsecured Notes | Other
Long-term debt, net of unamortized debt discount
Principal Amount	12,000,000			12,000,000
Total long-term debt and other	12,000,000			12,000,000
Revolving Credit Facility | Revolving Credit Facility Due June 2023
Long-term debt, net of unamortized debt discount
Principal Amount	$ 0			75,000,000
Stated interest rate on debt (as a percent)	5.04%
Total long-term debt and other	$ 0			$ 75,000,000