EMPLOYEE-RELATED BENEFITS - Current and Long-Term Employee-Related Benefits (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Current:
Accrued payroll and withholding taxes	$ 320	$ 263
Peruvian workers' participation	17	19
Employee pension benefits	7	5
Other post-retirement benefit plans	6	6
Accrued severance	1	2
Other employee-related payables	10	10
Employee-related benefits, Current	361	305
Non-current:
Employee pension benefits	115	149
Accrued severance	228	163
Other post-retirement benefit plans	80	76
Other employee-related payables	25	13
Employee-related benefits, Non-current	$ 448	$ 401