RISK MANAGEMENT AND HEDGING ACTIVITIES USING DERIVATIVES Part 1 (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Derivative, Fair Value [Line Items]
Derivative, Net Liability Position, Aggregate Fair Value	$ 0
Derivatives designated as hedging instruments
Derivative, Fair Value [Line Items]
Assets	167,871	$ 67,030
(Liabilities)	(344,080)	(231,537)
Natural Gas Pipelines
Derivative, Fair Value [Line Items]
Derivative, Fair Value, Net	0	0
Other Current Assets [Member] \| Commodity contracts \| Financial contracts \| Derivatives designated as hedging instruments
Derivative, Fair Value [Line Items]
Assets	167,871	64,858
(Liabilities)	(73,783)	(26,997)
Other Current Liabilities [Member] \| Interest-rate contracts \| Derivatives designated as hedging instruments
Derivative, Fair Value [Line Items]
Assets	0	0
(Liabilities)	(28,673)	(90,161)
Other Deferred Credits \| Commodity contracts \| Financial contracts \| Derivatives designated as hedging instruments
Derivative, Fair Value [Line Items]
Assets	0	1,591
(Liabilities)	0	(2,599)
Other Deferred Credits \| Interest-rate contracts \| Derivatives designated as hedging instruments
Derivative, Fair Value [Line Items]
Assets	0
(Liabilities)	(241,624)	(111,780)
Other Assets [Member] \| Interest-rate contracts \| Derivatives designated as hedging instruments
Derivative, Fair Value [Line Items]
Assets		581
Interest-rate contracts \| LIBOR Based Interest Payments [Member] \| Cash Flow Hedging [Member] \| Forward Contracts
Derivative, Fair Value [Line Items]
Derivative, Notional Amount	$ 1,300,000	$ 1,300,000

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The aggregate fair value amounts of derivative instruments that contain credit-risk-related contingent features that are in a net liability position at the end of the reporting period. For nonderivative instruments that are designated and qualify as hedging instruments, the fair value amounts are the carrying value of the nonderivative hedging instrument, including the adjustment for the foreign currency transaction gain (loss) on that instrument.

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