Shareholders' Equity - Additional Information (Detail) - shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2018	Dec. 31, 2014	Dec. 31, 2000
Equity [Abstract]
Number of shares outstanding	87,353,432
Maximum number of shares that may yet be purchased	2,986,288
Stock repurchase program, number of shares authorized to be repurchased			47,500,000	10,000,000
Shares repurchased	0	0