Shares and Stockholders' Equity (Reconciliation Of The Denominator Calculations Of Basic And Diluted EPS) (Details) - shares	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Reconciliation of the denominator (number of shares) in the calculations of basic and diluted earnings (loss) per common share
Weighted-average shares, as used in basic calculation	234,181,717	250,629,243	260,877,533
Shares to cover exercise of outstanding warrants	1,089,221	1,389,768	4,342,860
Shares to cover non-vested stock	1,109,490	1,302,859	1,522,737
Average stock options outstanding during the period	2,256,720	3,162,508	3,828,292
Assumed acquisition of shares with assumed proceeds from exercising outstanding warrants	(248,402)	(262,709)	(894,175)
Assumed acquisition of shares with assumed proceeds and benefits from exercising stock options (at average market price for the period)	(1,508,620)	(2,258,658)	(2,679,571)
Shares repurchaseable from measured but unrecognized stock option expense	(49,839)	(45,958)	(75,268)
Average deferred compensation shares		1,021,059	1,041,587
Weighted-average shares, as used in diluted calculation	236,830,287	254,938,112	267,963,995