EMPLOYEE BENEFIT PLANS - Weighted Average Asset Allocations (Details)	Dec. 31, 2021	Dec. 31, 2020
Plan's asset allocations by asset category
Weighted-average asset allocations by asset category (as a percent)	100.00%	100.00%
Cash
Plan's asset allocations by asset category
Weighted-average asset allocations by asset category (as a percent)	5.09%	3.62%
Fixed income securities
Plan's asset allocations by asset category
Weighted-average asset allocations by asset category (as a percent)	12.29%	12.99%
Equity
Plan's asset allocations by asset category
Weighted-average asset allocations by asset category (as a percent)	68.76%	69.06%
Inflation Hedges/Real Assets
Plan's asset allocations by asset category
Weighted-average asset allocations by asset category (as a percent)	5.23%	5.16%
Hedged Strategies
Plan's asset allocations by asset category
Weighted-average asset allocations by asset category (as a percent)	8.63%	9.17%