Income Taxes - Schedule Of Income Tax Difference From Statutory Rate (Detail) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Federal tax at statutory rate	$ 343.3	$ 265.5	$ 192.2
State taxes, net of federal benefits	14.0	8.9	6.4
Foreign rate differential	(86.2)	(67.4)	(47.4)
Research and development credit	(7.8)	(6.4)	(5.0)
Share-based compensation not benefited	3.6	6.9	7.7
Domestic production activities deduction	(8.0)	(5.3)	(4.6)
Reversal of unrecognized tax benefits	(15.8)	(6.4)	(20.3)
Reversal of share-based compensation from intercompany charges	0.0	(25.0)	0.0
Other	1.8	(1.1)	1.2
Total income tax expense	$ 244.9	$ 169.7	$ 130.2

Effective Income Tax Rate Reconciliation, Reversal of Share-Based Compensation From Intercompany Charges

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Income Tax Reconciliation Unrecognized Tax Benefits Reductions Resulting From Lapse Of Applicable Statute Of Limitations

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Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

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Amount of the difference between reported income tax expense (benefit) and the expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to deduction for qualified production activity.

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The amount of income tax expense or benefit for the period computed by applying the domestic federal statutory tax rates to pretax income from continuing operations.

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