LONG-TERM DEBT - Notices of Default Under Senior Note Indentures (Details)	Sep. 30, 2016	May 19, 2016	Apr. 22, 2016	Apr. 12, 2016	Dec. 31, 2015
5.50% Senior Notes due March 2023
Debt Instrument [Line Items]
Stated interest rate on debt (as a percent)	5.50%	5.50%		5.50%	5.50%
5.375% Senior Notes due March 2020
Debt Instrument [Line Items]
Stated interest rate on debt (as a percent)	5.375%		5.375%		5.375%
7.50% Senior Notes due in July 2021
Debt Instrument [Line Items]
Stated interest rate on debt (as a percent)	7.50%	7.50%	7.50%		7.50%
6.375% Senior Notes due in October 2020
Debt Instrument [Line Items]
Stated interest rate on debt (as a percent)	6.375%		6.375%		6.375%
7.25% Senior Notes due in July 2022
Debt Instrument [Line Items]
Stated interest rate on debt (as a percent)	7.25%	7.25%	7.25%		7.25%