FINANCIAL INSTRUMENTS (Narrative) (Details) - USD ($) $ in Millions	1 Months Ended	6 Months Ended	12 Months Ended	18 Months Ended
	Mar. 31, 2015	Jun. 30, 2015	Dec. 31, 2015	Mar. 31, 2015	Mar. 15, 2015	Dec. 31, 2014	Mar. 31, 2014	Jul. 24, 2012
To be Retired in Q1 and Q2 2015 [Member]
Derivative [Line Items]
Face amount of debt		$ 1,300
Cash Flow Hedging [Member]
Derivative [Line Items]
Accumulated net loss from designated or qualifying cash flow hedges			$ 12			$ 15
Net amount of deferred gains and losses on cash flow hedges that is expected to be reclassified within the next 12 months			3
Forward Starting Interest Rate Swaps [Member]
Derivative [Line Items]
Gain (loss) on derivatives				$ (17)
Forward Starting Interest Rate Swaps [Member] | Cash Flow Hedging [Member]
Derivative [Line Items]
Derivative, notional amount							$ 150
Treasury Lock [Member]
Derivative [Line Items]
Gain (loss) on derivatives	$ 3
Treasury Lock [Member] | Cash Flow Hedging [Member]
Derivative [Line Items]
Derivative, notional amount	$ 350			$ 350
Interest Rate Swaps [Member]
Derivative [Line Items]
Derivative asset designated as hedging instrument fair value on termination								$ 72
Amount to be amortized as a reduction of interest expense			$ 28					$ 65
Reverse Treasury Locks [Member] | Economic Hedges [Member] | Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Derivative, notional amount					$ 280
Reverse Treasury Locks [Member] | Economic Hedges [Member] | Not Designated as Hedging Instrument [Member] | Other Operating Income (Expense) [Member]
Derivative [Line Items]
Derivative instruments not designated as hedging instruments, gain		$ 3