Stock-based Compensation - Company's Options Outstanding (Detail)	12 Months Ended
	Dec. 31, 2019 $ / shares shares
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items]
Options Outstanding - Number of Shares (in shares)	4,192,122
Options Exercisable - Number of Shares (in shares)	2,792,940
$1.92
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items]
Exercise Price, Minimum (in dollars per share) | $ / shares	$ 0
Exercise Price, Maximum (in dollars per share) | $ / shares	$ 1.92
Options Outstanding - Number of Shares (in shares)	309,208
Options Outstanding -Weighted- Average Remaining Contractual Life in Years	2 years 2 months 20 days
Options Exercisable - Number of Shares (in shares)	309,208
Options Exercisable - Weighted- Average Remaining Contractual Life in Years	2 years 2 months 20 days
$2.24 – $6.72
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items]
Exercise Price, Minimum (in dollars per share) | $ / shares	$ 2.24
Exercise Price, Maximum (in dollars per share) | $ / shares	$ 6.72
Options Outstanding - Number of Shares (in shares)	187,205
Options Outstanding -Weighted- Average Remaining Contractual Life in Years	1 year 11 months 13 days
Options Exercisable - Number of Shares (in shares)	186,227
Options Exercisable - Weighted- Average Remaining Contractual Life in Years	1 year 11 months 1 day
$6.80 – $12.56
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items]
Exercise Price, Minimum (in dollars per share) | $ / shares	$ 6.80
Exercise Price, Maximum (in dollars per share) | $ / shares	$ 12.56
Options Outstanding - Number of Shares (in shares)	857,753
Options Outstanding -Weighted- Average Remaining Contractual Life in Years	7 years 1 month 20 days
Options Exercisable - Number of Shares (in shares)	485,456
Options Exercisable - Weighted- Average Remaining Contractual Life in Years	6 years 4 months 24 days
$12.77
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items]
Exercise Price, Minimum (in dollars per share) | $ / shares	$ 12.77
Exercise Price, Maximum (in dollars per share) | $ / shares	$ 12.77
Options Outstanding - Number of Shares (in shares)	324,905
Options Outstanding -Weighted- Average Remaining Contractual Life in Years	5 years 1 month 11 days
Options Exercisable - Number of Shares (in shares)	324,905
Options Exercisable - Weighted- Average Remaining Contractual Life in Years	5 years 1 month 11 days
$12.89 – $12.94
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items]
Exercise Price, Minimum (in dollars per share) | $ / shares	$ 12.89
Exercise Price, Maximum (in dollars per share) | $ / shares	$ 12.94
Options Outstanding - Number of Shares (in shares)	297,516
Options Outstanding -Weighted- Average Remaining Contractual Life in Years	6 years 1 month 30 days
Options Exercisable - Number of Shares (in shares)	276,318
Options Exercisable - Weighted- Average Remaining Contractual Life in Years	6 years 1 month 16 days
$13.01 – $14.95
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items]
Exercise Price, Minimum (in dollars per share) | $ / shares	$ 13.01
Exercise Price, Maximum (in dollars per share) | $ / shares	$ 14.95
Options Outstanding - Number of Shares (in shares)	227,294
Options Outstanding -Weighted- Average Remaining Contractual Life in Years	6 years 5 months 20 days
Options Exercisable - Number of Shares (in shares)	184,704
Options Exercisable - Weighted- Average Remaining Contractual Life in Years	6 years 17 days
$14.99 – $17.48
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items]
Exercise Price, Minimum (in dollars per share) | $ / shares	$ 14.99
Exercise Price, Maximum (in dollars per share) | $ / shares	$ 17.48
Options Outstanding - Number of Shares (in shares)	319,666
Options Outstanding -Weighted- Average Remaining Contractual Life in Years	6 years 6 months 17 days
Options Exercisable - Number of Shares (in shares)	248,011
Options Exercisable - Weighted- Average Remaining Contractual Life in Years	6 years 2 months 4 days
$17.83 – $18.90
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items]
Exercise Price, Minimum (in dollars per share) | $ / shares	$ 17.83
Exercise Price, Maximum (in dollars per share) | $ / shares	$ 18.90
Options Outstanding - Number of Shares (in shares)	729,182
Options Outstanding -Weighted- Average Remaining Contractual Life in Years	6 years 15 days
Options Exercisable - Number of Shares (in shares)	568,562
Options Exercisable - Weighted- Average Remaining Contractual Life in Years	5 years 7 months 21 days
$19.09 – $22.71
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items]
Exercise Price, Minimum (in dollars per share) | $ / shares	$ 19.09
Exercise Price, Maximum (in dollars per share) | $ / shares	$ 22.71
Options Outstanding - Number of Shares (in shares)	252,012
Options Outstanding -Weighted- Average Remaining Contractual Life in Years	8 years 1 month 10 days
Options Exercisable - Number of Shares (in shares)	109,271
Options Exercisable - Weighted- Average Remaining Contractual Life in Years	6 years 8 months 24 days
$23.00 - $29.13
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items]
Options Outstanding - Number of Shares (in shares)	687,381
Options Outstanding -Weighted- Average Remaining Contractual Life in Years	9 years 4 months 5 days
Options Exercisable - Number of Shares (in shares)	100,278
Options Exercisable - Weighted- Average Remaining Contractual Life in Years	9 years 2 months 26 days