Stock-Based Compensation - Additional Information (Detail) shares in Millions, $ in Millions	3 Months Ended
Mar. 31, 2019 USD ($) shares
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Unrecognized stock-based compensation expense \| $	$ 114.1
Weighted-average period of recognition of unrecognized stock-based compensation expense (in years)	2 years 4 months
Shares issued (in shares) \| shares	0.5

No definition available.

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- Definition

Unrecognized cost of unvested share-based compensation awards.

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- Definition

Weighted average period over which unrecognized compensation is expected to be recognized for equity-based compensation plans, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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- Definition

Number of share options (or share units) exercised during the current period.

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