CONTINGENCIES AND COMMITMENTS (Detail) - USD ($)			6 Months Ended
	Jan. 04, 2018	Oct. 10, 2013	Jun. 30, 2018	Dec. 31, 2017	Mar. 29, 2017
Loss Contingencies [Line Items]
Malpractice Loss Contingency, Claims Incurred in Period			$ 400,000,000
Standby Letters Of Credit [Member]
Loss Contingencies [Line Items]
Letters of credit, outstanding			19,700,000	$ 21,300,000
FinancialStandbyLetterOfCreditMember
Loss Contingencies [Line Items]
Letters of credit, outstanding			14,000,000	$ 14,600,000
Failure to Meet Contractual Obligations [Member]
Loss Contingencies [Line Items]
Damages sought		$ 25,000,000
Surety Bond [Member]
Loss Contingencies [Line Items]
Surety Bond Outstanding			56,000,000
Damage from Fire, Explosion or Other Hazard [Member]
Loss Contingencies [Line Items]
Estimated Litigation Liability			1,000,000,000
Minimum [Member]
Loss Contingencies [Line Items]
Range of possible loss			0
Maximum [Member]
Loss Contingencies [Line Items]
Range of possible loss			56,000,000
Westinghouse Electric Company (WEC) [Member] | Pending Litigation [Member]
Loss Contingencies [Line Items]
Debtor-in-Possession Financing, Amount Arranged					$ 800,000,000
AP1000 US [Member] | Minimum [Member]
Loss Contingencies [Line Items]
Range of possible loss			0
AP1000 US [Member] | Maximum [Member]
Loss Contingencies [Line Items]
Range of possible loss			31,000,000
Westinghouse Electric Company (WEC) [Member] | Collectibility of Receivables [Member]
Loss Contingencies [Line Items]
Range of possible loss			$ 2,900,000
Westinghouse Electric Company (WEC) [Member]
Loss Contingencies [Line Items]
Business Combination, Consideration Transferred	$ 4,600,000,000