Warrants (Summary of Warrant Activity) (Details) - $ / shares	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Warrants Summary Of Warrant Activity Details
Warrants, Outstanding as of beginning of period	6,526,000	8,091,000	5,131,000
Granted with exercise price less than intrinsic value	0	0	2,216,000
Granted with exercise price greater than intrinsic value	0	2,148,000	1,855,000
Exercised	(1,487,000)	(3,713,000)	(358,000)
Canceled/expired	0	0	(753,000)
Warrants, Outstanding as of end of period	5,039,000	6,526,000	8,091,000
Warrants, Weighted-Average Exercise Prices, Outstanding as of beginnig of period	$ 3.08	$ 3.07	$ 7.28
Warrants, Weighted-Average Exercise Prices, Granted less than intrinsic value	0	0	2.71
Warrants, Weighted-Average Exercise Prices, Granted greater than intrinsic value	$ 0	$ 2.47	$ 2.44
Warrants, Weighted-Average Exercise Prices, Exercised	2.19	2.67	1.77
Warrants, Weighted-Average Exercise Prices, cancelled or expired	$ 0	$ 0	$ 28.80
Warrants, Weighted-Average Exercise Prices, Outstanding as of end of period	$ 3.34	$ 3.08	$ 3.07
Warrants, Exercisable at end of period	5,039,000
Warrants, Weighted-Average Exercise Price, Exercisable	$ 3.34