Stock-Based Compensation - Summary of Stock Option Activity and Related Information (Detail) $ / shares in Units, shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2019 USD ($) $ / shares shares
Weighted Average Exercise Price
Average remaining contractual life exercisable	2 years 2 months 12 days
Average remaining contractual life outstanding	2 years 2 months 12 days
Beginning balance (in dollars per share) | $ / shares	$ 16.00
Granted (in dollars per share) | $ / shares	0
Exercised (in dollars per share) | $ / shares	7.29
Forfeited (in dollars per share) | $ / shares	16.40
Ending balance (in dollars per share) | $ / shares	16.84
Exercisable at end of period (in dollars per share) | $ / shares	$ 16.84
Option Outstanding
Beginning balance (in shares) | shares	1.1
Granted (in shares) | shares	0.0
Exercised (in shares) | shares	0.1
Forfeited (in shares) | shares	0.3
Ending balance (in shares) | shares	0.7
Exercisable at end of period (in shares) | shares	0.7
Aggregate Intrinsic Value
Beginning balance | $	$ 0.3
Ending balance | $	0.2
Exercisable at end of period | $	$ 0.2