Common Equity Common Stock And Treasury Stock Shares Activity (Details) - USD ($) $ in Thousands		1 Months Ended	12 Months Ended
	Dec. 12, 2018	May 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Class of Stock and Treasury Stock [Line Items]
Proceeds from Issuance of Common Stock	$ 500,000	$ 608,000	$ 0	$ 607,650	$ 499,272
Common Stock [Member]
Common Stock And Treasury Stock [Roll Forward]
Beginning Balance			270,035,180	261,587,009	254,752,788
Forward Contract Indexed to Issuer's Equity, Shares	6,834,221		0	8,448,171	6,834,221
Ending Balance			270,035,180	270,035,180	261,587,009
Treasury Stock [Member]
Common Stock And Treasury Stock [Roll Forward]
Beginning Balance			70,886,400	72,530,866	74,235,135
Employee Stock-Based Compensation Plans			(1,076,511)	(1,624,358)	(1,683,174)
Directors' Plan			(19,543)	(20,108)	(21,095)
Ending Balance			69,790,346	70,886,400	72,530,866