DERIVATIVE INSTRUMENTS (Narrative) (Details)		1 Months Ended	3 Months Ended		9 Months Ended		12 Months Ended
		Aug. 31, 2011 USD ($)	Sep. 30, 2016 USD ($)	Sep. 30, 2015 USD ($)	Sep. 30, 2016 USD ($)	Sep. 30, 2015 USD ($)	Dec. 31, 2007 USD ($) agreement	Dec. 31, 2015 USD ($)	Jun. 30, 2011 USD ($)
Derivative [Line Items]
Amortized deferred gain			$ 0	$ 282,000	$ 0	$ 2,795,000
10.125% notes due 2015 [Member]
Derivative [Line Items]
Gain component of the settlement	[1]		0	241,000	0	241,000		$ 0
Designated as Hedging Instrument [Member] | Cash Flow Hedges [Member] | Interest Rate Swap [Member]
Derivative [Line Items]
Number of forward starting interest rate swap agreements | agreement							15
Notional amount of interest rate swap agreements							$ 1,500,000,000
Cash payments for interest rate swap agreements							$ 89,777,000
Loss reclassified from AOCI			507,000	$ 467,000	1,490,000	9,282,000
Estimated amount of pretax loss in AOCI reclassified to earnings for the next 12-month period			$ 2,135,000		$ 2,135,000
Designated as Hedging Instrument [Member] | Cash Flow Hedges [Member] | Interest Rate Swap [Member] | Debt [Member]
Derivative [Line Items]
Loss reclassified from AOCI						7,208,000
Designated as Hedging Instrument [Member] | Fair Value Hedges [Member] | Interest Rate Swap [Member]
Derivative [Line Items]
Cash proceeds from interest rate swap agreements		$ 25,382,000
Gain component of the settlement		23,387,000
Accrued interest		$ 1,995,000
Amortized deferred gain						$ 1,642,000
Fixed-Rate Notes | 6.50% notes due 2016 [Member]
Derivative [Line Items]
Fixed-rate notes issued									$ 500,000,000
Interest rate									6.50%
Fixed-Rate Notes | 10.125% notes due 2015 [Member]
Derivative [Line Items]
Interest rate									10.125%
Fixed-Rate Notes | Designated as Hedging Instrument [Member] | Fair Value Hedges [Member] | Interest Rate Swap [Member] | 6.50% notes due 2016 [Member]
Derivative [Line Items]
Notional amount of interest rate swap agreements									$ 500,000,000
Fixed interest rate under swap agreements									6.50%
Fixed-Rate Notes | Designated as Hedging Instrument [Member] | Fair Value Hedges [Member] | Interest Rate Swap [Member] | 10.125% notes due 2015 [Member]
Derivative [Line Items]
Notional amount of interest rate swap agreements									$ 150,000,000
Fixed interest rate under swap agreements									10.125%
LIBOR [Member] | Fixed-Rate Notes | Designated as Hedging Instrument [Member] | Fair Value Hedges [Member] | Interest Rate Swap [Member] | 6.50% notes due 2016 [Member]
Derivative [Line Items]
Interest rate spread above London Interbank Offered Rate (LIBOR)									4.05%
LIBOR [Member] | Fixed-Rate Notes | Designated as Hedging Instrument [Member] | Fair Value Hedges [Member] | Interest Rate Swap [Member] | 10.125% notes due 2015 [Member]
Derivative [Line Items]
Interest rate spread above London Interbank Offered Rate (LIBOR)									8.03%

[1] The unamortized deferred gain was realized upon the August 2011 settlement of interest rate swaps as described in Note 6.