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Stock-Based Compensation - Summary of Significant Ranges of Outstanding and Exercisable Options (Detail) - Options shares in Thousands	9 Months Ended
	Sep. 30, 2019 $ / shares shares
$3.72 - $14.99
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Lower range limit (in dollars per share)	$ 3.72
Upper range limit (in dollars per share)	$ 14.99
Number Outstanding (in shares) | shares	64
Weighted Average Remaining Contractual Life	9 years 4 months 6 days
Weighted Average Exercise Price (in dollars per share)	$ 3.96
Number Exercisable (in shares) | shares | shares	11
Weighted Average Exercise Price (in dollars per share)	$ 4.00
$15.00 - $25.59
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Lower range limit (in dollars per share)	15.00
Upper range limit (in dollars per share)	$ 25.59
Number Outstanding (in shares) | shares	8
Weighted Average Remaining Contractual Life	4 years 18 days
Weighted Average Exercise Price (in dollars per share)	$ 15.00
Number Exercisable (in shares) | shares | shares	5
Weighted Average Exercise Price (in dollars per share)	$ 15.00
$25.60 - $143.99
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Lower range limit (in dollars per share)	25.60
Upper range limit (in dollars per share)	$ 143.99
Number Outstanding (in shares) | shares	3
Weighted Average Remaining Contractual Life	4 years 9 months 29 days
Weighted Average Exercise Price (in dollars per share)	$ 41.88
Number Exercisable (in shares) | shares | shares	2
Weighted Average Exercise Price (in dollars per share)	$ 46.93
$144.00 - $409.99
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Lower range limit (in dollars per share)	144.00
Upper range limit (in dollars per share)	$ 409.99
Number Outstanding (in shares) | shares	5
Weighted Average Remaining Contractual Life	6 years 10 months 24 days
Weighted Average Exercise Price (in dollars per share)	$ 144.00
Number Exercisable (in shares) | shares | shares	5
Weighted Average Exercise Price (in dollars per share)	$ 144.00
$410.00 - $924.00
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Lower range limit (in dollars per share)	410.0
Upper range limit (in dollars per share)	$ 924.00
Number Outstanding (in shares) | shares	1
Weighted Average Remaining Contractual Life	5 years 5 months 8 days
Weighted Average Exercise Price (in dollars per share)	$ 430.64
Number Exercisable (in shares) | shares | shares	1
Weighted Average Exercise Price (in dollars per share)	$ 430.64
$3.72 - $924.00
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Lower range limit (in dollars per share)	3.72
Upper range limit (in dollars per share)	$ 924.00
Number Outstanding (in shares) | shares	81
Weighted Average Remaining Contractual Life	8 years 5 months 15 days
Weighted Average Exercise Price (in dollars per share)	$ 20.36
Number Exercisable (in shares) | shares | shares	24
Weighted Average Exercise Price (in dollars per share)	$ 56.81

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The floor of a customized range of exercise prices for purposes of disclosing shares potentially issuable under outstanding stock option awards on all stock option plans and other required information pertaining to awards in the customized range.

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The number of shares reserved for issuance pertaining to the outstanding exercisable stock options as of the balance sheet date in the customized range of exercise prices for which the market and performance vesting condition has been satisfied.

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The number of shares reserved for issuance pertaining to the outstanding stock options as of the balance sheet date for all option plans in the customized range of exercise prices.

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Weighted average exercise price as of the balance sheet date for those equity-based payment arrangements exercisable and outstanding.

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The weighted average price as of the balance sheet date at which grantees could acquire the underlying shares with respect to all outstanding stock options which are in the customized range of exercise prices.

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Weighted average remaining contractual term of outstanding stock options, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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