EMPLOYEE BENEFIT PLANS - Weighted-Average Assumptions, Pension Plans (Details) - Pension Plans	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
United States
Summary of weighted-average actuarial assumptions used in determining annual pension expense
Discount rate (as a percent)	3.18%	4.35%	3.70%
Rate of increase in compensation levels (as a percent)	3.00%	3.00%	3.00%
Expected long-term rate of return on plan assets (as a percent)	5.05%	5.40%	5.40%
Gain and loss amortization period (years)	21 years	22 years	21 years
Foreign Plans
Summary of weighted-average actuarial assumptions used in determining annual pension expense
Discount rate (as a percent)	2.28%	3.04%	2.70%
Rate of increase in compensation levels (as a percent)	3.11%	3.08%	3.08%
Expected long-term rate of return on plan assets (as a percent)	4.99%	5.36%	5.50%
Gain and loss amortization period (years)	24 years	24 years	26 years