Shares and Stockholders' Equity (Changes In Preferred And Common stock (Number Of Shares)) (Details) - shares		3 Months Ended		6 Months Ended
		Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Changes In Preferred And Common Stock Number Of Shares [Line Items]
Balance as of beginning-of-period				226,335,105
Balance as of end-of-period		222,237,262		222,237,262
Common stock as of end-of-period:
Basic basis		222,237,262	232,784,691	222,237,262	232,784,691
Diluted basis	[1]	226,044,165	236,179,176	226,044,165	236,179,176
Common Stock [Member]
Changes In Preferred And Common Stock Number Of Shares [Line Items]
Balance as of beginning-of-period		224,888,259	239,005,252	226,335,105	243,835,893
Stock issued for exercise of warrants		289,636	13,335	334,930	38,148
Stock compensation/issued for benefit plans		89,455	9,537	1,461,286	670,142
Retirement/cancellation of shares		(3,030,088)	(6,243,433)	(5,894,059)	(11,759,492)
Balance as of end-of-period		222,237,262	232,784,691	222,237,262	232,784,691

[1] Effective October 1, 2016, we early adopted ASU 2016-09, Improvements to Employee Share-Based Payment Accounting. We have updated certain previously reported interim results and metrics as of January 1, 2016, in accordance with this guidance. For more information, see Note 1 - Earnings Per Share in our 2016 Form 10-K.