Share-based Compensation - Summary of Restricted Share Activity (Detail) - Restricted Stock Units (RSUs) [Member]	12 Months Ended
	Dec. 31, 2019 $ / shares shares
Shares
Outstanding, beginning balance (in shares) | shares	897,005
Granted (in shares) | shares	219,202
Vested and issued (in shares) | shares	(486,239)
Expired or forfeited (in shares) | shares	(158,697)
Outstanding, ending balance (in shares) | shares	471,271
Weighted-Average Grant Date Fair Value
Outstanding, weighted-average grant date fair value, beginning balance (in dollars per share) | $ / shares	$ 46.82
Granted (in dollars per share) | $ / shares	68.50
Vested and issued (in dollars per share) | $ / shares	40.32
Expired or forfeited (in dollars per share) | $ / shares	57.96
Outstanding, weighted-average grant date fair value, ending balance (in dollars per share) | $ / shares	$ 60.09