CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY - USD ($) $ in Thousands		Total		Common Stock	Preferred Stock	Capital surplus	Retained earnings	Treasury stock	Accumulated other comprehensive income (loss)
Beginning balance at Dec. 31, 2020		$ 6,028,687		$ 1,045	$ 22,143	$ 4,571,534	$ 2,260,928	$ (1,016,954)	$ 189,991
Increase Decrease In Stockholders Equity
Net income		728,825					728,825
Issuance of stock		3,461		1		3,460
Dividends declared:
Common stock	[1]	(106,354)	[2]				(106,354)
Preferred stock		(1,059)					(1,059)
Common stock purchases	[3]	(355,571)				(8,557)		(347,014)
Stock based compensation		15,068				3,204		11,864
Other comprehensive loss, net of tax		(330,086)							(330,086)
Ending balance at Sep. 30, 2021		5,982,971		1,046	22,143	4,569,641	2,882,340	(1,352,104)	(140,095)
Beginning balance at Jun. 30, 2021		5,814,614		1,045	22,143	4,506,659	2,670,885	(1,290,427)	(95,691)
Increase Decrease In Stockholders Equity
Net income		248,114					248,114
Issuance of stock		1,235		1		1,234
Dividends declared:
Common stock	[2]	(36,306)					(36,306)
Preferred stock		(353)					(353)
Common stock purchases	[4]	(264)				61,443		(61,707)
Stock based compensation		335				305		30
Other comprehensive loss, net of tax		(44,404)							(44,404)
Ending balance at Sep. 30, 2021		5,982,971		1,046	22,143	4,569,641	2,882,340	(1,352,104)	(140,095)
Beginning balance at Dec. 31, 2021		5,969,397		1,046	22,143	4,650,182	2,973,745	(1,352,650)	(325,069)
Increase Decrease In Stockholders Equity
Net income		845,502					845,502
Issuance of stock		4,285				4,285
Dividends declared:
Common stock		(124,168)					(124,168)
Preferred stock		(1,059)					(1,059)
Common stock purchases	[5]	(637,520)				(5,882)		(631,638)
Stock based compensation		17,663				3,923		13,740
Other comprehensive loss, net of tax		(2,399,262)							(2,399,262)
Ending balance at Sep. 30, 2022		3,674,838		1,046	22,143	4,652,508	3,694,020	(1,970,548)	(2,724,331)
Beginning balance at Jun. 30, 2022		4,293,349		1,046	22,143	4,576,478	3,311,951	(1,665,253)	(1,953,016)
Increase Decrease In Stockholders Equity
Net income		422,395					422,395
Issuance of stock		1,550				1,550
Dividends declared:
Common stock	[6]	(39,973)					(39,973)
Preferred stock		(353)					(353)
Common stock purchases		(231,225)				74,118		(305,343)
Stock based compensation		410				362		48
Other comprehensive loss, net of tax		(771,315)							(771,315)
Ending balance at Sep. 30, 2022		$ 3,674,838		$ 1,046	$ 22,143	$ 4,652,508	$ 3,694,020	$ (1,970,548)	$ (2,724,331)

[1] Dividends declared per common share during the nine months ended September 30, 2022 - $1.65 (2021 - $1.30).

[2] Dividends declared per common share during the quarter ended September 30, 2022 - $0.55 (2021 - $0.45).

[3] During the nine months ended September 30, 2021, the Corporation entered into a $350 million accelerated share repurchase transaction with respect to its common stock, which was accounted for as a treasury stock transaction. Refer to Note 18 for additional information.

[4] During the quarter ended September 30, 2021, the Corporation completed a $350 million accelerated share repurchase transaction with respect to its common stock, which was accounted for as a treasury stock transaction. Refer to Note 18 for additional information.

[5] During the nine months ended September 30, 2022, the Corporation completed a $400 million accelerated share repurchase transaction with respect to its common stock and entered into an additional $231 million accelerated share repurchase transaction with respect to its common stock. Both were accounted for as a treasury stock transaction. Refer to Note 18 for additional information.

[6] During July 2022, the Corporation completed a $400 million accelerated share repurchase transaction with respect to its common stock. During August 2022, the Corporation entered into a $231 million accelerated share repurchase transaction with respect to its common stock. Both were accounted for as treasury stock transactions. Refer to Note 18 for additional information.