Stock Based Compensation (Details 1) (USD $)	3 Months Ended	12 Months Ended
	Mar. 31, 2012	Dec. 31, 2011
Summary of nonvested stock activity and restricted stock activity excluding salary shares
Granted, Shares	2,923,611	1,624,369
Nonvested Stock Options [Member]
Summary of nonvested stock activity and restricted stock activity excluding salary shares
Stock Options Shares Outstanding, Beginning balance	2,431,339	2,025,720
Granted, Shares	2,923,611	1,624,369
Vested, Shares	(990,296)	(955,454)
Forfeited, Shares	(68,226)	(263,296)
Stock Options Shares Outstanding, Ending balance	4,296,428	2,431,339
Nonvested Weighted Average Grant Date Fair Value, Beginning balance	5.11	4.09
Granted Weighted Average Grant Date Fair Value	5.10	5.56
Vested Weighted Average Grant Date Fair Value	4.86	3.77
Forfeited Weighted Average Grant Date Fair Value	5.13	4.85
Nonvested Weighted Average Grant Date Fair Value, Ending balance	5.16	5.11