CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY - USD ($) $ in Thousands		Total	Cumulative effect adoption adjustment	Common Stock	Preferred Stock	Capital surplus	Retained earnings	Retained earnings Cumulative effect adoption adjustment	Treasury stock	Accumulated other comprehensive income (loss)
Beginning Balance at Dec. 31, 2018		$ 5,435,057	$ 4,905	$ 1,043	$ 50,160	$ 4,365,606	$ 1,651,731	$ 4,905	$ (205,509)	$ (427,974)
Increase Decrease In Stockholders Equity [Roll Forward]
Net income		167,925					167,925
Issuance of stock		793				793
Dividends declared:
Common stock	[1]	(28,986)					(28,986)
Preferred stock		(931)					(931)
Common stock purchases	[2]	(253,119)				(52,670)			(200,449)
Common stock reissuance		2,183				178			2,005
Stock based compensation		8,238				(867)			9,105
Other comprehensive loss, net of tax		103,995								103,995
Ending Balance at Mar. 31, 2019		5,440,060		1,043	50,160	4,313,040	1,794,644		(394,848)	(323,979)
Beginning Balance at Dec. 31, 2019		6,016,779	$ (205,842)	1,044	50,160	4,447,412	2,147,915	$ (205,842)	(459,814)	(169,938)
Increase Decrease In Stockholders Equity [Roll Forward]
Net income		34,302					34,302
Issuance of stock		863				863
Dividends declared:
Common stock	[1]	(35,505)					(35,505)
Preferred stock		(700)					(700)
Common stock purchases	[3]	(502,801)				(77,066)			(425,735)
Common stock reissuance		3,106				(563)			3,669
Preferred stock redemption	[4]	(28,017)			(28,017)
Stock based compensation		6,859				(4,346)			11,205
Other comprehensive loss, net of tax		380,561								380,561
Ending Balance at Mar. 31, 2020		$ 5,669,605		$ 1,044	$ 22,143	$ 4,366,300	$ 1,940,170		$ (870,675)	$ 210,623

[1] Dividends declared per common share during the quarter ended March 31, 2020 - $0.40 (2019 - $0.30).

[2] During the quarter ended March 31, 2019, the Corporation entered into a $250 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.

[3] On January 30, 2020, the Corporation entered into a $500 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] On February 24, 2020, the Corporation redeemed all the outstanding shares of 2008 Series B Preferred Stock. Refer to Note 18 for additional information.