INCOME TAXES (Details 2)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Effective Tax Rate Reconciliation (Percent)
Statutory federal tax rate	21.00%	21.00%	35.00%
State income taxes, net	(5.40%)	2.00%	(1.20%)
Foreign rate differential	19.40%	1.80%	(7.70%)
U.S. tax on foreign earnings	0.00%	1.10%	(70.80%)
Salt depletion	29.00%	(2.40%)	(16.10%)
Change in valuation allowance	(64.90%)	3.80%	76.00%
Remeasurement of U.S. state deferred taxes	16.10%	(0.60%)	10.20%
Change in tax contingencies	35.40%	(0.70%)	(7.70%)
U.S. Tax Cuts and Jobs Act	0.00%	(0.80%)	(373.50%)
Share-based payments	0.70%	0.00%	(5.70%)
Dividends paid to Contributing Employee Ownership Plan	1.10%	(0.10%)	(0.60%)
Return to provision	15.00%	(0.10%)	(0.60%)
U.S. federal tax credits	6.40%	(0.40%)	(4.20%)
Other, net	(4.40%)	0.40%	(2.00%)
Effective tax rate	69.40%	25.00%	(368.90%)