CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Preferred Stock [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	Additional Paid-in Capital [Member] Preferred Stock [Member]	Retained Earnings [Member]	Retained Earnings [Member] Cumulative Effect, Period of Adoption, Adjustment [Member]	Treasury Stock [Member]	Accumulated Other Comprehensive Loss, net of tax [Member]
Balance at beginning of period at Dec. 31, 2020		$ 36,104	$ 22,303	$ 965,385		$ 1,215,321		$ (19,389)	$ 55,455
Balance at beginning of period (ASU 2022-02) at Dec. 31, 2020							$ 0
Redemption of Series A through E Preferred Stock		(36,104)
Common stock repurchases (See Note 17)								(216,522)
Common stock reissued/issued under stock-based compensation plan				(63)
Common stock issued stock-based compensation plan			63					0
Stock-based compensation expense				5,460
Restricted stock forfeited				531
Restricted stock forfeited								(531)
Net income	$ 281,025					281,025
Dividends on common stock (2023 - $0.56 per share; 2022 - $0.46 per share; 2021 - $0.31 per share)						(65,364)
Dividends on preferred stock						(2,453)
Issuance costs of Series A through E Preferred Stock redeemed					$ 1,234
Excess of redemption value over carrying value of Series A through E Preferred Stock redeemed	(1,234)					(1,234)
Other comprehensive income (loss), net of tax	(139,454)								(139,454)
Balance at end of period at Dec. 31, 2021	2,101,767	0	22,366	972,547		1,427,295		(236,442)	(83,999)
Balance at end of period (ASU 2022-02) at Dec. 31, 2021							0
Redemption of Series A through E Preferred Stock		0
Common stock repurchases (See Note 17)								(277,769)
Common stock reissued/issued under stock-based compensation plan				(7,365)
Common stock issued stock-based compensation plan			0					7,365
Stock-based compensation expense				5,407
Restricted stock forfeited				133
Restricted stock forfeited								(133)
Net income	305,072					305,072
Dividends on common stock (2023 - $0.56 per share; 2022 - $0.46 per share; 2021 - $0.31 per share)						(88,158)
Dividends on preferred stock						0
Issuance costs of Series A through E Preferred Stock redeemed					0
Excess of redemption value over carrying value of Series A through E Preferred Stock redeemed	0					0
Other comprehensive income (loss), net of tax	(720,779)								(720,779)
Balance at end of period at Dec. 31, 2022	1,325,540	0	22,366	970,722		1,644,209		(506,979)	(804,778)
Balance at end of period (ASU 2022-02) at Dec. 31, 2022							$ (1,357)
Redemption of Series A through E Preferred Stock		0
Common stock repurchases (See Note 17)								(203,241)
Common stock reissued/issued under stock-based compensation plan				(13,531)
Common stock issued stock-based compensation plan			0					13,531
Stock-based compensation expense				7,799
Restricted stock forfeited				717
Restricted stock forfeited								(717)
Net income	302,864					302,864
Dividends on common stock (2023 - $0.56 per share; 2022 - $0.46 per share; 2021 - $0.31 per share)						(99,604)
Dividends on preferred stock						0
Issuance costs of Series A through E Preferred Stock redeemed					$ 0
Excess of redemption value over carrying value of Series A through E Preferred Stock redeemed	0					0
Other comprehensive income (loss), net of tax	165,608								165,608
Balance at end of period at Dec. 31, 2023	$ 1,497,609	$ 0	$ 22,366	$ 965,707		$ 1,846,112		$ (697,406)	$ (639,170)