Stockholders Equity - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Millions	6 Months Ended
Jun. 30, 2017	Jun. 30, 2016
Stockholders Equity Note [Line Items]
Share based compensation awarded	519,791
Weighted-average grant date fair value of options granted	$ 24.30	$ 27.42
Non Vested Stock Options
Stockholders Equity Note [Line Items]
Estimated unrecognized employee compensation cost related to non-vested stock options granted	$ 90.7
Estimated unrecognized employee compensation cost related to non-vested stock options granted, Weighted-average period of recognition	1 year 6 months
Restricted Stock Units
Stockholders Equity Note [Line Items]
Estimated unrecognized employee compensation cost related to non-vested stock options granted	$ 31.8
Estimated unrecognized employee compensation cost related to non-vested stock options granted, Weighted-average period of recognition	2 years 4 months 24 days
Shares vesting period	3 years
2011 Plan
Stockholders Equity Note [Line Items]
Common stock shares reserved for issuance	12,529,412
2017 Employment Inducement Incentive Award Plan
Stockholders Equity Note [Line Items]
Common stock shares reserved for issuance	1,000,000
Share based compensation awarded	0
Maximum \| 2011 Plan
Stockholders Equity Note [Line Items]
Stock options granted, term	10 years
Maximum \| 2017 Employment Inducement Incentive Award Plan
Stockholders Equity Note [Line Items]
Stock options granted, term	10 years

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- Definition

Stockholders equity note.

+ References

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- Definition

Aggregate number of common shares reserved for future issuance.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.29)
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- Definition

Unrecognized cost of unvested share-based compensation awards.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
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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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Period which an employee's right to exercise an award is no longer contingent on satisfaction of either a service condition, market condition or a performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
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- Definition

Gross number of share options (or share units) granted during the period.

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- Definition

The weighted average grant-date fair value of options granted during the reporting period as calculated by applying the disclosed option pricing methodology.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
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-URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901

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