Shares and Stockholders' Equity (Reconciliation Of The Denominator Calculations Of Basic And Diluted EPS) (Details) - shares	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
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	231,041,085	249,227,641	236,374,010	252,167,909
Shares to cover exercise of outstanding warrants	1,088,717	1,219,729	1,096,356	1,476,038
Shares to cover non-vested stock	1,110,342	1,229,031	1,057,199	1,314,445
Average stock options outstanding during the period	2,405,396	2,646,184	2,107,456	3,388,172
Assumed acquisition of shares with assumed proceeds from exercising outstanding warrants	(247,909)	(236,042)	(268,177)	(275,928)
Assumed acquisition of shares with assumed proceeds and benefits from exercising stock options (at average market price for the period)	(1,721,612)	(1,870,146)	(1,525,970)	(2,424,332)
Shares repurchaseable from measured but unrecognized stock option expense	(87,623)	(33,847)	(42,368)	(53,413)
Average deferred compensation shares		1,028,061	1,080,205	1,024,369
Weighted-average shares, as used in diluted calculation	233,588,396	253,210,611	239,878,711	256,617,260