DERIVATIVE INSTRUMENTS (Narrative) (Details) (USD $)	1 Months Ended	3 Months Ended		12 Months Ended	3 Months Ended
	Aug. 31, 2011	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2007 agreement	Mar. 31, 2016	Jun. 30, 2011
Derivative [Line Items]
Number of forward starting interest rate swap agreements				15
Payments for (Proceeds from) settlement of interest rate swap agreements	$ (25,382,000)			$ 89,777,000
Loss reclassified from AOCI		2,700,000	3,762,000
Long-term notes issued						500,000,000
Interest rate						6.50%
Forward component of the settlement	23,387,000
Accrued interest income	1,995,000
Amortized deferred gain		513,000	9,194,000
Interest Rate Swap Agreements [Member]
Derivative [Line Items]
Derviative, notional amount				1,500,000,000
Interest Rate Swap Agreement One [Member]
Derivative [Line Items]
Derviative, notional amount						500,000,000
Interest rate spread above London Interbank Offered Rate (LIBOR)						4.05%
Fixed interest rate under swap agreement						6.50%
Interest Rate Swap Agreement Two [Member]
Derivative [Line Items]
Derviative, notional amount						150,000,000
Interest rate spread above London Interbank Offered Rate (LIBOR)						8.03%
Fixed interest rate under swap agreement						10.125%
Debt [Member]
Derivative [Line Items]
Amortized deferred gain			8,032,000
Notes Issued One [Member]
Derivative [Line Items]
Interest rate						10.125%
Scenario, Forecast [Member]
Derivative [Line Items]
Estimated amount of pretax loss in AOCI related to interest rate swap that would be reclassified to earnings within the next 12 months					6,604,000
Acceleration of a proportional amount of the deferred loss					$ 4,503,000