Shares and Stockholders' Equity (Reconciliation Of The Denominator Calculations Of Basic And Diluted EPS) (Details) - shares		3 Months Ended
		Mar. 31, 2017	Mar. 31, 2016
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		225,619,803	241,676,363
Shares to cover exercise of outstanding warrants		1,023,429	1,101,947
Shares to cover non-vested stock	[1]	1,675,799	1,063,150
Average stock options outstanding during the period		2,681,129	1,806,644
Assumed acquisition of shares with assumed proceeds from exercising outstanding warrants		(150,236)	(291,520)
Assumed acquisition of shares with assumed proceeds and benefits from exercising stock options (at average market price for the period)	[1]	(1,619,156)	(1,299,510)
Shares repurchaseable from measured but unrecognized stock option expense		(77,078)	(1,103)
Average deferred compensation shares		949,815	1,039,929
Weighted-average shares, as used in diluted calculation	[1]	230,103,505	245,095,900

[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 the new guidance. For more information, see Note 1 - Earnings Per Share in our 2016 Form 10-K.