DEBT AND OTHER OBLIGATIONS DEBT AND OTHER OBLIGATIONS - Summary of Debt Covenant Calculations (Details)	Dec. 31, 2017 USD ($)
Minimum
Debt Instrument [Line Items]
Consolidated net worth margin, requirement	$ 0
Consolidated net worth margin, actual results	$ 1,000,000,000
Maximum
Debt Instrument [Line Items]
Debt to total capital ratio, requirement	40.00%
Debt to total capital ratio, actual results	22.00%