Shareholders' Equity Total compensation cost related to nonvested awards (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock Issued During Period, Shares, Restricted Stock Award, Gross	917,907	514,700
weighted average estimated fair value of restricted stock	$ 5.44	$ 6.53
Stock Issued During Period, Value, Restricted Stock Award, Gross	$ 4,996,300	$ 3,360,000
Restricted Stock [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Unrecognized compensation cost	528,600
Excepted weighted-average period in years of compensation cost to be recognized	0 years 3 months 22 days
Warrant [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Unrecognized compensation cost	7,200
Excepted weighted-average period in years of compensation cost to be recognized	0 years 6 months 15 days
Stock Option [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Unrecognized compensation cost	$ 4,598,400
Excepted weighted-average period in years of compensation cost to be recognized	3 years 9 months 15 days