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Stock-Based Compensation - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Millions	1 Months Ended	3 Months Ended
	Jan. 31, 2020	Mar. 31, 2020	Mar. 31, 2019
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Weighted average grant date fair value of options granted, per share		$ 1.46	$ 4.78
Grant date fair values of options vested		$ 3.0	$ 1.2
Aggregate intrinsic values of options exercised		0.0	1.9
Unrecognized compensation cost		$ 21.9
Weighted average period for recognition of compensation costs		2 years 6 months
Restricted Stock Units (RSUs)
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Weighted average period for recognition of compensation costs		2 years 3 months 18 days
Total grant date fair value of RSUs		$ 12.9	5.0
Total fair value of RSUs vested		1.9	$ 0.1
Unrecognized stock based compensation cost		$ 25.2
Shares expected to vest		7,546,191
Chief Executive Officer \| Restricted Stock Units (RSUs) \| First Anniversary
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting percentage	42.00%
Chief Executive Officer \| Restricted Stock Units (RSUs) \| Second and Third Anniversary
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting percentage	29.00%
Employees \| Restricted Stock Units (RSUs)
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting period		3 years