Aggregate notional amount specified by the derivative(s). Expressed as an absolute value.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Accumulated change, net of tax, in accumulated gains and losses from derivative instruments designated and qualifying as the effective portion of cash flow hedges. Includes an entity's share of an equity investee's Increase or Decrease in deferred hedging gains or losses.

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Fair value, after the effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes liabilities not subject to a master netting arrangement and not elected to be offset.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Date the derivative contract matures, in CCYY-MM-DD format.

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The estimated net amount of unrealized gains or losses on foreign currency cash flow hedges at the reporting date expected to be reclassified to earnings within the next 12 months.

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Fair value portion of liability contracts related to the exchange of different currencies, including, but not limited to, foreign currency options, forward (delivery or nondelivery) contracts, and swaps entered into.

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The estimated net amount of unrealized gains or losses on interest rate cash flow hedges as of the balance sheet date expected to be reclassified to earnings within the next twelve months.

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Derivative Financial Instruments - Additional Information (Detail) - USD ($)	9 Months Ended
	Sep. 30, 2018	May 08, 2018	Dec. 31, 2017
Derivative [Line Items]
Net gain (loss) on derivative financial instruments	$ (15,000,000)		$ (2,000,000)
Interest Rate Swap [Member]
Derivative [Line Items]
Net gain (loss) on derivative financial instruments	(400,000)
Net deferred gains expected to be reclassified from AOCI over next 12 months	300,000
Interest Rate Swap [Member] \| Designated as Hedging Instrument [Member] \| Cash Flow Hedging [Member]
Derivative [Line Items]
Notional value of outstanding derivative contracts		$ 1,940,000,000
Fair value of swap arrangement in net liability position	400,000
Term Facility [Member] \| Interest Rate Swap [Member] \| Designated as Hedging Instrument [Member] \| Cash Flow Hedging [Member]
Derivative [Line Items]
Notional value of outstanding derivative contracts		$ 1,940,000,000
Foreign Exchange Rate [Member]
Derivative [Line Items]
Notional value of outstanding derivative contracts	$ 930,000,000
Derivative contracts, maturity date	Aug. 31, 2022
Fair value of derivative contracts	$ 14,000,000
Net gain (loss) on derivative financial instruments	(13,000,000)
Net deferred losses expected to be reclassified from AOCI over next 12 months	$ (7,000,000)