EMPLOYEE RETIREMENT PLANS - Qualified Defined-benefit Pension Plan Weighted Average Asset Allocation (Details) - Qualified	Dec. 31, 2019	Dec. 31, 2018
Plan Assets
Weighted average asset allocation (as a percent)	100.00%	100.00%
Equity securities
Plan Assets
Weighted average asset allocation (as a percent)	41.00%	34.00%
Debt securities
Plan Assets
Weighted average asset allocation (as a percent)	54.00%	49.00%
Other
Plan Assets
Weighted average asset allocation (as a percent)	5.00%	17.00%