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 Millions	1 Months Ended	3 Months Ended		6 Months Ended
	Jun. 30, 2017 USD ($)	Jun. 30, 2017 USD ($)	Jun. 30, 2016 USD ($)	Jun. 30, 2017 USD ($)	Jun. 30, 2016 USD ($)	Jun. 30, 2017 EUR (€)	Mar. 31, 2017 USD ($)	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		$ 700,000	$ 15,900,000	$ 2,500,000	$ 16,800,000
Interest expense reclassified		75,354,000	76,455,000	148,266,000	157,267,000
Debt	$ 11,081,922,000	11,081,922,000		11,081,922,000					$ 10,608,294,000
Amount of gain (loss) included in AOCI		3,162,000	(23,061,000)	42,829,000	(21,600,000)
Senior notes	6,700,000,000	6,700,000,000		6,700,000,000
Forward Contracts
Derivative Instruments Gain Loss [Line Items]
Amount of gain (loss) included in AOCI		(7,200,000)	0	(11,300,000)	0
Foreign Currency Options [Member]
Derivative Instruments Gain Loss [Line Items]
Amount of gain (loss) included in AOCI	0
Designated As Hedging Instrument [Member] | Forward Contracts
Derivative Instruments Gain Loss [Line Items]
Debt							$ 3,500,000,000	€ 3,100.0	$ 3,400,000,000	€ 3,200.0
Designated As Hedging Instrument [Member] | Foreign Currency Options [Member]
Derivative Instruments Gain Loss [Line Items]
Senior notes	645,300,000	645,300,000		645,300,000		€ 500.0
Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member]
Derivative Instruments Gain Loss [Line Items]
Interest expense reclassified		1,500,000	$ 1,100,000	2,900,000	$ 2,100,000
Amount to be reclassified to interest expense, next 12 months	$ 4,800,000	$ 4,800,000		$ 4,800,000