Warrants Outstanding and Exercisable (Details) (USD $)	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Warrant, exercise price	7.28	22.08	25.84
Warrants, Outstanding as of end of period	5,131,000	2,287,000	1,042,000
Warrants, Exercisable at end of period	3,031,000
Warrants exercisable, weighted average exercise price	$ 10.49
2.13
Warrants, Outstanding as of end of period	1,000,000
Warrants outstanding, weighted average remaining contractual life, years	2.39
Warrants outstanding, weighted average exercise price	2.13
Warrants, Exercisable at end of period	1,000,000
Warrants exercisable, weighted average exercise price	$ 2.13
2.65
Warrants, Outstanding as of end of period	2,100,000
Warrants outstanding, weighted average remaining contractual life, years	4.47
Warrants outstanding, weighted average exercise price	2.65
Warrants, Exercisable at end of period	0
Warrants exercisable, weighted average exercise price	$ 0
6.24
Warrants, Outstanding as of end of period	1,278,000
Warrants outstanding, weighted average remaining contractual life, years	3.88
Warrants outstanding, weighted average exercise price	6.24
Warrants, Exercisable at end of period	1,278,000
Warrants exercisable, weighted average exercise price	$ 6.24
28.80
Warrants, Outstanding as of end of period	753,000
Warrants outstanding, weighted average remaining contractual life, years	0.56
Warrants outstanding, weighted average exercise price	28.00
Warrants, Exercisable at end of period	753,000
Warrants exercisable, weighted average exercise price	$ 28.80