DEBT AND FINANCING COSTS - Additional Information (Detail) £ in Millions		1 Months Ended	3 Months Ended
	Feb. 01, 2018 USD ($)	Mar. 31, 2018 USD ($) Contract	Mar. 31, 2018 USD ($)	Mar. 31, 2018 GBP (£)	Mar. 31, 2018 GBP (£)	Dec. 31, 2017 USD ($)
Debt Instrument [Line Items]
Number of credit facilities terminated | Contract		2
Write off of deferred loan costs		$ 4,000,000
Commercial Paper
Debt Instrument [Line Items]
Debt instrument, face amount		3,500,000,000.0	$ 3,500,000,000.0
Debt instrument term			270 days	270 days
Letter of Credit
Debt Instrument [Line Items]
Credit facility maximum borrowing capacity		3,000,000,000.0	$ 3,000,000,000.0
Line of credit facility, committed amount		$ 2,080,000,000	2,080,000,000
Line of credit facility aggregate commitment amount | £					£ 129.1
Revolving Credit Facility
Debt Instrument [Line Items]
Line of credit facility, number of extension options | Contract		2
Extended financing agreement term		1 year
Credit facility maximum borrowing capacity		$ 5,000,000,000.0	5,000,000,000.0
Line of credit facility, committed amount		4,000,000,000	4,000,000,000
Letters of credit outstanding, amount		0	0
Credit Facility $3.5 Billion
Debt Instrument [Line Items]
Debt extinguished amount			3,500,000,000
Credit Facility £900 Million
Debt Instrument [Line Items]
Debt extinguished amount | £				£ 900.0
Unsecured Debt
Debt Instrument [Line Items]
Debt instrument, face amount		8,430,000,000	8,430,000,000			$ 8,580,000,000
Unsecured Debt | 6.9% senior notes due September 15, 2018
Debt Instrument [Line Items]
Debt instrument, face amount		$ 400,000,000	$ 400,000,000
Debt instrument, stated interest rate		6.90%	6.90%		6.90%
Unsecured Debt | 7.0% senior notes due February 1, 2018
Debt Instrument [Line Items]
Debt instrument, face amount						$ 150,000,000
Debt instrument, stated interest rate						7.00%
Debt extinguished amount	$ 150,000,000