Shareholders' Equity - Additional Information (Detail) - $ / shares shares in Thousands				3 Months Ended	9 Months Ended
	Nov. 02, 2020	May 05, 2020	May 07, 2019	Mar. 31, 2019	Sep. 30, 2020	Sep. 30, 2019
Class of Stock [Line Items]
Date of declaration of dividends		May 05, 2020	May 07, 2019
Dividend declared per share		$ 0.52	$ 0.50
Date of dividend payment		Jun. 15, 2020	Jun. 17, 2019
Dividends payable to shareholders date of record		Jun. 01, 2020	Jun. 03, 2019
Subsequent Event
Class of Stock [Line Items]
Date of declaration of dividends	Nov. 02, 2020
Dividend declared per share	$ 0.52
Date of dividend payment	Dec. 15, 2020
Dividends payable to shareholders date of record	Dec. 01, 2020
Discretionary Plan
Class of Stock [Line Items]
Expected common stock shares issued and outstanding					160,000
Shares repurchased					4,400	4,002
Average price per share					$ 71.41	$ 72.57
Non-Discretionary Plan
Class of Stock [Line Items]
Shares repurchased				88
Average price per share				$ 74.03