SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Going Concern Considerations (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Debt Instrument [Line Items]
Cash on balance sheet	$ 845,030				$ 772,678					$ 845,030	$ 772,678	$ 457,024	$ 708,151
Cash payments of principal and interest on debt, net of facility draws and proceeds received										2,081,300
Cash interest payment obligations in 2017	460,189	$ 459,852	$ 465,991	$ 463,950	$ 456,847	$ 453,921	$ 452,957	$ 441,771		1,849,982	$ 1,805,496	$ 1,741,596
Debt maturities, 2017	343,500									343,500
Debt maturities, 2019	8,369,000									8,369,000
Scenario, Forecast
Debt Instrument [Line Items]
Cash interest payment obligations in 2017									$ 1,700,000
Receivables based credit facility
Debt Instrument [Line Items]
Excess availability under receivables based credit facility	113,600									113,600
Debt maturities, 2017	330,000									330,000
Subsidiary
Debt Instrument [Line Items]
Cash on balance sheet	542,000									542,000
Debt maturities, 2018	503,000									503,000
Parent Company
Debt Instrument [Line Items]
Debt maturities, 2018	$ 559,100									$ 559,100