CONDENSED CONSOLIDATED STATEMENTS OF COMMON SHAREHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Common Shares	Capital Surplus, Paid In	Retained Earnings	Accumulated Other Comprehensive Loss	Treasury Stock
Balance (in shares) at Dec. 31, 2020		342,954,023
Balance at Dec. 31, 2020	$ 14,063,566	$ 1,789,092	$ 8,015,663	$ 4,613,201	$ (76,411)	$ (277,979)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income	368,023			368,023
Dividends on Common Stock	(206,913)			(206,913)
Dividends on Preferred Stock	(1,880)			(1,880)
Long-Term Incentive Plan Activity	(15,727)		(15,727)
Issuance of Treasury Shares (in shares)		480,275
Issuance of Treasury Shares	25,163		16,182			8,981
Other Comprehensive Income, Net of Tax	1,188				1,188
Balance (in shares) at Mar. 31, 2021		343,434,298
Balance at Mar. 31, 2021	14,233,420	$ 1,789,092	8,016,118	4,772,431	(75,223)	(268,998)
Balance (in shares) at Dec. 31, 2020		342,954,023
Balance at Dec. 31, 2020	14,063,566	$ 1,789,092	8,015,663	4,613,201	(76,411)	(277,979)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income	919,468
Dividends on Preferred Stock	(5,600)
Other Comprehensive Income, Net of Tax	4,546
Balance (in shares) at Sep. 30, 2021		343,774,324
Balance at Sep. 30, 2021	14,411,611	$ 1,789,092	8,050,872	4,906,151	(71,865)	(262,639)
Balance (in shares) at Mar. 31, 2021		343,434,298
Balance at Mar. 31, 2021	14,233,420	$ 1,789,092	8,016,118	4,772,431	(75,223)	(268,998)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income	266,400			266,400
Dividends on Common Stock	(206,893)			(206,893)
Dividends on Preferred Stock	(1,880)			(1,880)
Long-Term Incentive Plan Activity	6,162		6,162
Issuance of Treasury Shares (in shares)		166,805
Issuance of Treasury Shares	13,799		10,679			3,120
Other Comprehensive Income, Net of Tax	881				881
Balance (in shares) at Jun. 30, 2021		343,601,103
Balance at Jun. 30, 2021	14,311,889	$ 1,789,092	8,032,959	4,830,058	(74,342)	(265,878)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income	285,046			285,046
Dividends on Common Stock	(207,073)			(207,073)
Dividends on Preferred Stock	(1,880)			(1,880)
Long-Term Incentive Plan Activity	6,478		6,478
Issuance of Treasury Shares (in shares)		173,221
Issuance of Treasury Shares	14,674		11,435			3,239
Other Comprehensive Income, Net of Tax	2,477				2,477
Balance (in shares) at Sep. 30, 2021		343,774,324
Balance at Sep. 30, 2021	$ 14,411,611	$ 1,789,092	8,050,872	4,906,151	(71,865)	(262,639)
Balance (in shares) at Dec. 31, 2021	344,403,196	344,403,196
Balance at Dec. 31, 2021	$ 14,599,844	$ 1,789,092	8,098,514	5,005,391	(42,275)	(250,878)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income	445,326			445,326
Dividends on Common Stock	(219,768)			(219,768)
Dividends on Preferred Stock	(1,880)			(1,880)
Long-Term Incentive Plan Activity	(16,538)		(16,538)
Issuance of Treasury Shares (in shares)		447,076
Issuance of Treasury Shares	29,002		20,642			8,360
Other Comprehensive Income, Net of Tax	704				704
Balance (in shares) at Mar. 31, 2022		344,850,272
Balance at Mar. 31, 2022	$ 14,836,690	$ 1,789,092	8,102,618	5,229,069	(41,571)	(242,518)
Balance (in shares) at Dec. 31, 2021	344,403,196	344,403,196
Balance at Dec. 31, 2021	$ 14,599,844	$ 1,789,092	8,098,514	5,005,391	(42,275)	(250,878)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income	1,090,356
Dividends on Preferred Stock	(5,600)
Other Comprehensive Income, Net of Tax	$ 1,269
Balance (in shares) at Sep. 30, 2022	347,348,749	347,348,749
Balance at Sep. 30, 2022	$ 15,279,173	$ 1,799,920	8,327,477	5,429,076	(41,006)	(236,294)
Balance (in shares) at Mar. 31, 2022		344,850,272
Balance at Mar. 31, 2022	14,836,690	$ 1,789,092	8,102,618	5,229,069	(41,571)	(242,518)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income	293,742			293,742
Dividends on Common Stock	(219,877)			(219,877)
Dividends on Preferred Stock	(1,880)			(1,880)
Issuance of Common Shares (in shares)		1,392,804
Issuance of Common Shares	128,106	$ 6,964	121,142
Long-Term Incentive Plan Activity	9,070		9,070
Issuance of Treasury Shares (in shares)		167,953
Issuance of Treasury Shares	14,481		11,340			3,141
Capital Stock Expense	(1,824)		(1,824)
Other Comprehensive Income, Net of Tax	(1,293)				(1,293)
Balance (in shares) at Jun. 30, 2022		346,411,029
Balance at Jun. 30, 2022	$ 15,057,215	$ 1,796,056	8,242,346	5,301,054	(42,864)	(239,377)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Par value (in dollars per share)	$ 5
Net Income	$ 351,289			351,289
Dividends on Common Stock	(221,387)			(221,387)
Dividends on Preferred Stock	(1,880)			(1,880)
Issuance of Common Shares (in shares)		772,867
Issuance of Common Shares	71,799	$ 3,864	67,935
Long-Term Incentive Plan Activity	7,407		7,407
Issuance of Treasury Shares (in shares)		164,853
Issuance of Treasury Shares	13,845		10,762			3,083
Capital Stock Expense	(973)		(973)
Other Comprehensive Income, Net of Tax	$ 1,858				1,858
Balance (in shares) at Sep. 30, 2022	347,348,749	347,348,749
Balance at Sep. 30, 2022	$ 15,279,173	$ 1,799,920	$ 8,327,477	$ 5,429,076	$ (41,006)	$ (236,294)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Par value (in dollars per share)	$ 5