Consolidated Statement of Changes in Stockholders' Equity - USD ($) $ in Thousands	Total	Cumulative Effect, Period of Adoption, Adjustment		Common Stock (Par Value: $0.01)	Preferred Stock (Par Value: $0.01)	Paid-in Capital in Excess of Par	Retained Earnings	Retained Earnings Cumulative Effect, Period of Adoption, Adjustment		Treasury Stock, at Cost	Accumulated Other Comprehensive Loss, Net of Tax
Balance at Dec. 31, 2018	$ 6,655,235			$ 4,904	$ 502,840	$ 6,099,940	$ 297,202			$ (161,998)	$ (87,653)
Balance, shares at Dec. 31, 2018				473,536,604
Shares issued for restricted stock, net of forfeitures						(16,501)				16,501
Shares issued for restricted stock, net of forfeitures, shares				1,665,028
Compensation expense related to restricted stock awards	23,937					23,937
Net income	293,869						293,869
Dividends paid on common stock ($0.17)	(238,043)						(238,043)
Dividends paid on preferred stock ($15.94)	(24,621)						(24,621)
Purchase of common stock	(75,172)									(75,172)
Purchase of common stock, shares				(7,850,772)
Other comprehensive income, net of tax	59,802										59,802
Balance at Sep. 30, 2019	6,695,007			$ 4,904	502,840	6,107,376	328,407			(220,669)	(27,851)
Balance, shares at Sep. 30, 2019				467,350,860
Balance at Jun. 30, 2019	6,674,678			$ 4,904	502,840	6,099,474	316,921			(220,546)	(28,915)
Balance, shares at Jun. 30, 2019				467,358,939
Shares issued for restricted stock, net of forfeitures						(222)				222
Shares issued for restricted stock, net of forfeitures, shares				22,980
Compensation expense related to restricted stock awards	8,124					8,124
Net income	99,046						99,046
Dividends paid on common stock ($0.17)	(79,353)						(79,353)
Dividends paid on preferred stock ($15.94)	(8,207)						(8,207)
Purchase of common stock	(345)									(345)
Purchase of common stock, shares				(31,059)
Other comprehensive income, net of tax	1,064										1,064
Balance at Sep. 30, 2019	6,695,007			$ 4,904	502,840	6,107,376	328,407			(220,669)	(27,851)
Balance, shares at Sep. 30, 2019				467,350,860
Balance at Dec. 31, 2019	$ 6,711,694	$ (10,468)	[1]	$ 4,904	502,840	6,115,487	342,023	$ (10,468)	[1]	(220,717)	(32,843)
Balance, shares at Dec. 31, 2019				467,346,781
Accounting Standards Update [Extensible List]	us-gaap:AccountingStandardsUpdate201613Member	us-gaap:AccountingStandardsUpdate201613Member						us-gaap:AccountingStandardsUpdate201613Member
Shares issued for restricted stock, net of forfeitures						(22,198)				22,198
Shares issued for restricted stock, net of forfeitures, shares				2,321,105
Compensation expense related to restricted stock awards	$ 24,613					24,613
Net income	321,445						321,445
Dividends paid on common stock ($0.17)	(236,851)						(236,851)
Dividends paid on preferred stock ($15.94)	(24,621)						(24,621)
Purchase of common stock	(59,002)									(59,002)
Purchase of common stock, shares				(5,763,802)
Other comprehensive income, net of tax	7,920										7,920
Balance at Sep. 30, 2020	6,734,730			$ 4,904	502,840	6,117,902	391,528			(257,521)	(24,923)
Balance, shares at Sep. 30, 2020				463,904,084
Balance at Jun. 30, 2020	6,693,013			$ 4,904	502,840	6,109,597	362,724			(257,232)	(29,820)
Balance, shares at Jun. 30, 2020				463,933,831
Compensation expense related to restricted stock awards	8,305					8,305
Net income	115,770						115,770
Dividends paid on common stock ($0.17)	(78,759)						(78,759)
Dividends paid on preferred stock ($15.94)	(8,207)						(8,207)
Purchase of common stock	(289)									(289)
Purchase of common stock, shares				(29,747)
Other comprehensive income, net of tax	4,897										4,897
Balance at Sep. 30, 2020	$ 6,734,730			$ 4,904	$ 502,840	$ 6,117,902	$ 391,528			$ (257,521)	$ (24,923)
Balance, shares at Sep. 30, 2020				463,904,084

[1] Amount represents a $10.5 million cumulative adjustment, net of tax, to retained earnings as of January 1, 2020, as a result of the adoption of ASU 2016-13, Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments, which became effective January 1, 2020.