Financial Instruments - Additional Information (Detail)	3 Months Ended	6 Months Ended
	Jun. 30, 2018 USD ($) contract	Jun. 30, 2018 USD ($) contract	Jun. 30, 2017 swap
Derivative [Line Items]
Derivative losses included in AOCI	$ 2,400,000
Net investment hedge ineffectiveness		$ 0
Cash flow hedge ineffectiveness	0	$ 0
Foreign currency contract
Derivative [Line Items]
Term of derivative		12 months
Interest rate swaps
Derivative [Line Items]
Number of instruments terminated (swap) | swap			2
Foreign currency contract and two interest rate swap agreements
Derivative [Line Items]
Notional amount	1,900,000,000	$ 1,900,000,000
Pre-tax gain included in Other income, net	11,000,000
Pre-tax loss included in Interest expense	$ 25,000,000
Net Investment Hedging [Member] | Designated as Hedging Instrument [Member] | Foreign currency contract
Derivative [Line Items]
Number of derivatives matured (contract) | contract	4	4