FINANCING ARRANGEMENTS - Summary of Redemption Prices (Details) - Unsecured debt	6 Months Ended
	Jun. 30, 2019
Debt Instrument, Redemption [Line Items]
Redemption percentage of principal amount	100.00%
2027 Notes
Debt Instrument, Redemption [Line Items]
Redemption percentage of principal amount	104.875%
2027 Notes | Debt Instrument, Redemption, Period One
Debt Instrument, Redemption [Line Items]
Redemption percentage of principal amount	102.438%
2027 Notes | Debt Instrument, Redemption, Period Two
Debt Instrument, Redemption [Line Items]
Redemption percentage of principal amount	101.21%
2027 Notes | Debt Instrument, Redemption, Period Three
Debt Instrument, Redemption [Line Items]
Redemption percentage of principal amount	100.00%
2029 Notes
Debt Instrument, Redemption [Line Items]
Redemption percentage of principal amount	105.125%
2029 Notes | Debt Instrument, Redemption, Period One
Debt Instrument, Redemption [Line Items]
Redemption percentage of principal amount	102.563%
2029 Notes | Debt Instrument, Redemption, Period Two
Debt Instrument, Redemption [Line Items]
Redemption percentage of principal amount	101.281%
2029 Notes | Debt Instrument, Redemption, Period Three
Debt Instrument, Redemption [Line Items]
Redemption percentage of principal amount	100.00%