Shareholders' Equity - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended			9 Months Ended
	Sep. 30, 2021	Mar. 31, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Feb. 25, 2021	Dec. 31, 2020
Class of Stock [Line Items]
Cash dividends received	$ 7,058		$ 6,913	$ 23,197	$ 46,361
Repurchase of common stock	$ 1,114		$ 242	3,675	25,545
Market value of shares repurchased under equity compensation plans				$ 835	$ 736
Employee Stock
Class of Stock [Line Items]
Company's common stock in lieu of cash to exercise options to purchase shares (in shares)	0		7,820	0	12,488
Other Share Based Awards
Class of Stock [Line Items]
Company's common stock in lieu of cash to exercise options to purchase shares (in shares)	9,683		619	19,413	12,058
2021 Stock Repurchase Plan
Class of Stock [Line Items]
Repurchase of common stock (in shares)						2,000,000
Stock repurchase program, percentage of common stock						6.70%
Repurchase of common stock (in shares)	17,963			63,317
Repurchase of common stock	$ 730			$ 2,831
2019 Stock Repurchase Plan
Class of Stock [Line Items]
Repurchase of common stock (in shares)		223
Repurchase of common stock		$ 8
Cumulative number of shares repurchased (in shares)							858,717
Common Stock
Class of Stock [Line Items]
Repurchase of common stock (in shares)	27,646		8,439	82,953	838,408
Repurchase of common stock	$ 494		$ 151	$ 1,482	$ 14,946
Market value of shares repurchased under equity compensation plans	$ 384		$ 242	$ 836	$ 588