Share-based Compensation - Summary of Stock-Settled SARs Activity (Detail) - Stock-Settled SARs Activity	12 Months Ended
	Dec. 31, 2020 $ / shares shares
Shares
Outstanding, beginning balance (in shares) | shares	625,368
Exercised (in shares) | shares	(470,182)
Expired or forfeited (in shares) | shares	(15,031)
Outstanding, ending balance (in shares) | shares	140,155
Weighted-Average Exercise Price
Outstanding, weighted-average exercise price, beginning balance (in dollars per share) | $ / shares	$ 33.60
Exercised (in dollars per share) | $ / shares	32.75
Expired or forfeited (in dollars per share) | $ / shares	37.85
Outstanding, weighted-average exercise price, ending balance (in dollars per share) | $ / shares	$ 35.98