Shares and Stockholders' Equity (Changes In Common stock (Number Of Shares)) (Details) - shares	3 Months Ended
	Mar. 31, 2018	Mar. 31, 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	218,695,476
Common stock as of End-of-period:
Basic basis	218,695,476	224,888,259
Diluted basis	222,379,443	228,934,631
Common Stock [Member]
Changes In Preferred And Common Stock Number Of Shares [Line Items]
Balance as of beginning-of-period	218,090,114	226,335,105
Stock issued for exercise of warrants	20,040	45,294
Stock compensation/issued for benefit plans	585,322	1,371,831
Retirement/cancellation of shares		(2,863,971)
Balance as of end-of-period	218,695,476	224,888,259