FINANCING ARRANGEMENTS - Summary of Consolidated Long-term Debt (Details) - USD ($)	Mar. 31, 2020	Dec. 31, 2019	Dec. 30, 2019	May 23, 2019	Mar. 08, 2019
Long-term debt, net of unamortized debt discount
Principal Amount	$ 24,701,000,000	$ 26,188,000,000
Total long-term debt and other	24,428,000,000	25,895,000,000
Less: Current portion of long-term debt and other	4,000,000	1,234,000,000
Non-current portion of long-term debt	24,424,000,000	24,661,000,000
Term Loan B Facility Due June 2025
Long-term debt, net of unamortized debt discount
Principal Amount	3,766,000,000	3,869,000,000
Total long-term debt and other	3,671,000,000	3,768,000,000
Term Loan B Facility Due November 2025
Long-term debt, net of unamortized debt discount
Principal Amount	$ 1,275,000,000	1,275,000,000
Stated interest rate on debt (as a percent)	3.36%
Total long-term debt and other	$ 1,257,000,000	1,257,000,000
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	$ 1,243,000,000	1,242,000,000
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	$ 1,984,000,000	1,983,000,000
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	$ 1,734,000,000	1,733,000,000
Senior Secured Notes | 5.75% Senior Secured Notes Due August 2027
Long-term debt, net of unamortized debt discount
Principal Amount	$ 500,000,000	500,000,000
Stated interest rate on debt (as a percent)	5.75%
Total long-term debt and other	$ 493,000,000	493,000,000
Senior Unsecured Notes | 5.50% Senior Notes Due March 2023
Long-term debt, net of unamortized debt discount
Principal Amount	$ 292,000,000	402,000,000
Stated interest rate on debt (as a percent)	5.50%				5.50%
Total long-term debt and other	$ 291,000,000	400,000,000
Senior Unsecured Notes | 5.875% Senior Notes Due May 2023
Long-term debt, net of unamortized debt discount
Principal Amount	$ 201,000,000	1,448,000,000
Stated interest rate on debt (as a percent)	5.875%				5.875%
Total long-term debt and other	$ 200,000,000	1,441,000,000
Senior Unsecured Notes | 4.50% Senior Notes euro-denoted debt Due May 2023
Long-term debt, net of unamortized debt discount
Principal Amount	$ 1,655,000,000	1,682,000,000
Stated interest rate on debt (as a percent)	4.50%
Total long-term debt and other	$ 1,647,000,000	1,674,000,000
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	$ 3,231,000,000	3,230,000,000
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	$ 1,474,000,000	1,473,000,000
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%
Total long-term debt and other	$ 1,485,000,000	1,484,000,000
Senior Unsecured Notes | 8.50% Senior Notes Due January 2027
Long-term debt, net of unamortized debt discount
Principal Amount	$ 1,750,000,000	1,750,000,000
Stated interest rate on debt (as a percent)	8.50%				8.50%
Total long-term debt and other	$ 1,756,000,000	1,756,000,000
Senior Unsecured Notes | 7.00 % Senior Notes Due January 2028
Long-term debt, net of unamortized debt discount
Principal Amount	$ 750,000,000	750,000,000
Stated interest rate on debt (as a percent)	7.00%			7.00%
Total long-term debt and other	$ 741,000,000	741,000,000
Senior Unsecured Notes | 5.00% Senior Notes Due January 2028
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)	5.00%		5.00%
Total long-term debt and other	$ 1,234,000,000	1,234,000,000
Senior Unsecured Notes | 7.25 % Senior Notes Due May 2029
Long-term debt, net of unamortized debt discount
Principal Amount	$ 750,000,000	750,000,000
Stated interest rate on debt (as a percent)	7.25%			7.25%
Total long-term debt and other	$ 741,000,000	740,000,000
Senior Unsecured Notes | 5.25% Senior Notes Due January 2030
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)	5.25%		5.25%
Total long-term debt and other	$ 1,234,000,000	1,234,000,000
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	0
Stated interest rate on debt (as a percent)	3.36%
Total long-term debt and other	$ 0	$ 0