Shares and Stockholders' Equity (Changes In Common stock (Number Of Shares)) (Details) - shares	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Changes In Preferred And Common Stock Number Of Shares [Line Items]
Balance as of beginning-of-period			218,090,114
Balance as of end-of-period	217,294,051		217,294,051
Common stock as of End-of-period:
Basic basis	217,294,051	222,237,262	217,294,051	222,237,262
Diluted basis	220,722,270	226,044,165	220,722,270	226,044,165
Common Stock [Member]
Changes In Preferred And Common Stock Number Of Shares [Line Items]
Balance as of beginning-of-period	218,695,476	224,888,259	218,090,114	226,335,105
Stock issued for exercise of warrants	2,826	289,636	22,866	334,930
Stock compensation/issued for benefit plans	51,644	89,455	636,966	1,461,286
Retirement/cancellation of shares	(1,455,895)	(3,030,088)	(1,455,895)	(5,894,059)
Balance as of end-of-period	217,294,051	222,237,262	217,294,051	222,237,262