Shares and Stockholders' Equity (Changes In Common stock (Number Of Shares)) (Details) - shares	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Changes In Common Stock (Number Of Shares) [Line Items]
Balance as of beginning-of-year	205,862,760
Balance as of end-of-period	196,668,532	205,862,760
Common Stock [Member]
Changes In Common Stock (Number Of Shares) [Line Items]
Balance as of beginning-of-year	205,862,760	218,090,114	226,335,105
Stock issued for exercise of warrants	258,633	212,670	344,901
Stock compensation/issued for benefit plans	942,318	800,325	1,793,234
Retirement/cancellation of shares	(10,395,179)	(13,240,349)	(10,383,126)
Balance as of end-of-period	196,668,532	205,862,760	218,090,114
Common stock as of End-of-Period
Basic basis	196,668,532	205,862,760	218,090,114
Diluted basis	199,196,043	209,034,686	221,309,830