Stock-Based Compensation - Status of Stock Options (Detail) - Employee Stock Option - 2013 and 2017 Equity Incentive Plan - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Shares
Outstanding (in shares)	7,548,436	7,507,690
Vested (in shares)	4,361,497
Weighted- Average Exercise Price Per Share
Outstanding (in dollars per share)	$ 32.21	$ 33.25
Vested (in dollars per share)	$ 32.75
Weighted-Average Remaining Contractual Life
Outstanding (in years)	6 years 7 months 20 days
Vested (in years)	5 years 3 months 29 days
Aggregate Intrinsic Value
Outstanding	$ 5,913
Vested	$ 4,514