Stock Based Compensation (Details 2) (Restricted Stock Award [Member], USD $)	6 Months Ended	12 Months Ended
	Jun. 30, 2012	Dec. 31, 2011
Restricted Stock Award [Member]
Summary of Restricted Stock Awards Activity (Excluding Salary Shares)
Outstanding Shares, Beginning balance	1,013,765	772,262
Granted, Shares	499,114	593,437
Vested, Shares	(450,760)	(169,499)
Forfeited, Shares	(46,634)	(182,435)
Outstanding Shares, Ending balance	1,015,485	1,013,765
Outstanding, Weighted Average Grant Date Fair Value, Beginning balance	$ 13.79	$ 13.94
Granted, Weighted Average Grant Date Fair Value	$ 13.00	$ 14.27
Vested, Weighted Average Grant Date Fair Value	$ 13.37	$ 17.74
Forfeited, Weighted Average Grant Date Fair Value	$ 13.76	$ 13.86
Outstanding Weighted Average Grant Date Fair Value, Ending balance	$ 13.59	$ 13.79