Financial Instruments and Fair Value Measurements - Summary of Gains (Losses) From Change in Fair Value of Derivative Instruments Included in Other Comprehensive Income (Parenthetical) (Detail) € in Billions	3 Months Ended		12 Months Ended
	Mar. 31, 2017 USD ($)	Mar. 31, 2016 USD ($)	Mar. 31, 2018 USD ($)	Mar. 31, 2017 EUR (€)	Dec. 31, 2016 USD ($)	Dec. 31, 2016 EUR (€)
Derivative Instruments Gain Loss [Line Items]
Amount received from (paid for) on settlement of net investment hedges	$ 1,800,000	$ 900,000
Interest expense reclassified	72,912,000	80,812,000
Debt	10,966,932,000				$ 10,608,294,000
Amount of gain (loss) included in AOCI	39,667,000	1,461,000
Forward Contracts
Derivative Instruments Gain Loss [Line Items]
Amount of gain (loss) included in AOCI	(4,100,000)	0
Designated As Hedging Instrument [Member] | Forward Contracts
Derivative Instruments Gain Loss [Line Items]
Debt	3,400,000,000			€ 3.2	$ 3,400,000,000	€ 3.2
Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member]
Derivative Instruments Gain Loss [Line Items]
Interest expense reclassified	$ 1,400,000	$ 1,000,000
Scenario Forecast | Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member]
Derivative Instruments Gain Loss [Line Items]
Interest expense reclassified			$ 5,500,000