Shares and Stockholders' Equity (Changes In Common stock (Number Of Shares)) (Details) - shares	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Changes In Common Stock (Number Of Shares) [Line Items]
Balance as of beginning-of-year	196,668,532
Balance as of end-of-period	193,208,244
Common stock as of End-of-Period
Basic basis	193,208,244	202,987,229
Diluted basis	195,027,909	204,200,031
Common Stock [Member]
Changes In Common Stock (Number Of Shares) [Line Items]
Balance as of beginning-of-year	196,668,532	205,862,760
Stock issued for exercise of warrants		203,530
Stock compensation/issued for benefit plans	349,636	809,670
Retirement/cancellation of shares	(3,809,924)	(3,888,731)
Balance as of end-of-period	193,208,244	202,987,229