CONSOLIDATED STATEMENTS OF CHANGES IN SHAREHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Common Stock	Retained earnings	Accumulated other comprehensive income (loss)	Treasury stock
Beginning Balances (in shares) at Dec. 31, 2020		104,281,794			(6,259,865)
Beginning Balances at Dec. 31, 2020	$ 2,282,070	$ 1,638,947	$ 720,429	$ 48,664	$ (125,970)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	158,215		158,215
Other comprehensive income (loss)	(34,434)			(34,434)
Cash dividends declared :
Common stock at $0.23 per share in 2022 and $0.23 per share in 2021	(66,562)		(66,562)
Treasury Stock, Shares, Acquired					(4,633,355)
Treasury Stock, Value, Acquired, Cost Method	(108,077)				$ (108,077)
Exercise of stock options, net of shares purchased (in shares)					3,468
Exercise of stock options, net of shares purchased	(34)	(36)			$ (70)
Restricted stock awards, net of forfeitures (in shares)					350,755
Restricted stock awards, net of forfeitures	(2,644)	(9,414)			$ 6,770
Share-based compensation expense	7,568	$ 7,568
Ending Balances (in shares) at Sep. 30, 2021		104,281,794			(10,538,997)
Ending Balances at Sep. 30, 2021	2,236,170	$ 1,637,065	812,082	14,230	$ (227,207)
Beginning Balances (in shares) at Jun. 30, 2021		104,281,794			(8,082,285)
Beginning Balances at Jun. 30, 2021	2,269,507	$ 1,635,470	773,857	30,735	$ (170,555)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	60,012		60,012
Other comprehensive income (loss)	(16,505)			(16,505)
Cash dividends declared :
Common stock at $0.23 per share in 2022 and $0.23 per share in 2021	(21,787)		(21,787)
Treasury Stock, Shares, Acquired					(2,484,295)
Treasury Stock, Value, Acquired, Cost Method	(57,231)				$ (57,231)
Restricted stock awards, net of forfeitures (in shares)					27,583
Restricted stock awards, net of forfeitures	(59)	(638)			$ 579
Share-based compensation expense	2,233	$ 2,233
Ending Balances (in shares) at Sep. 30, 2021		104,281,794			(10,538,997)
Ending Balances at Sep. 30, 2021	2,236,170	$ 1,637,065	812,082	14,230	$ (227,207)
Retained Earnings (Accumulated Deficit)	837,473
Beginning Balances (in shares) at Dec. 31, 2021		104,281,794			(10,132,554)
Beginning Balances at Dec. 31, 2021	2,258,942	$ 1,640,358	837,473	(433)	$ (218,456)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	148,526		148,526
Other comprehensive income (loss)	(354,137)			(354,137)
Cash dividends declared :
Common stock at $0.23 per share in 2022 and $0.23 per share in 2021	(65,056)		(65,056)
Exercise of stock options, net of shares purchased (in shares)					15,660
Exercise of stock options, net of shares purchased	(177)	(160)			$ (337)
Restricted stock awards, net of forfeitures (in shares)					669,064
Restricted stock awards, net of forfeitures	(3,027)	(17,209)			$ 14,182
Share-based compensation expense	8,707	$ 8,707
Ending Balances (in shares) at Sep. 30, 2022		104,281,794			(9,447,830)
Ending Balances at Sep. 30, 2022	1,994,132	$ 1,631,696	920,943	(354,570)	$ (203,937)
Beginning Balances (in shares) at Jun. 30, 2022		104,281,794			(9,833,002)
Beginning Balances at Jun. 30, 2022	2,068,670	$ 1,637,237	887,006	(243,328)	$ (212,245)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	55,705		55,705
Other comprehensive income (loss)	(111,242)			(111,242)
Cash dividends declared :
Common stock at $0.23 per share in 2022 and $0.23 per share in 2021	(21,768)		(21,768)
Restricted stock awards, net of forfeitures (in shares)					385,172
Restricted stock awards, net of forfeitures	(112)	(8,420)			$ 8,308
Share-based compensation expense	2,879	$ 2,879
Ending Balances (in shares) at Sep. 30, 2022		104,281,794			(9,447,830)
Ending Balances at Sep. 30, 2022	1,994,132	$ 1,631,696	$ 920,943	$ (354,570)	$ (203,937)
Retained Earnings (Accumulated Deficit)	$ 920,943