Shareholders' Equity - Reconciliation of Basic and Diluted Weighted Average Shares Outstanding (Detail) - shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Equity [Abstract]
Basic weighted average shares outstanding (in shares)	106,075,267	109,213,524	112,872,581
Weighted average dilutive options outstanding (in shares)	1,149,327	2,167,726	2,376,372
Diluted weighted average shares outstanding (in shares)	107,224,594	111,381,250	115,248,953
Antidilutive shares (in shares)	2,476,019	21,556	1,161,521