Annual report pursuant to Section 13 and 15(d)

Stock-Based Compensation (Narrative) (Details)

Stock-Based Compensation (Narrative) (Details) - USD ($)	1 Months Ended												12 Months Ended
	Dec. 31, 2015	Jul. 30, 2015	May. 31, 2015	Apr. 30, 2015	Dec. 31, 2014	Sep. 30, 2014	May. 31, 2014	Mar. 31, 2014	Jul. 31, 2013	Apr. 30, 2013	Mar. 31, 2013	Feb. 28, 2013	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock compensation expense													$ 2,368,685	$ 1,634,162	$ 2,908,269
Weighted-average grant date fair value of options granted													$ 1.67	$ 1.56	$ 1.81
Options exercised in period													146,625	468,000	60,000
Aggregate intrinsic value of options exercised in period													$ 144,000	$ 582,000	$ 126,000
Issued stock upon exercise of stock options, net, shares													124,238	299,360	39,649
Proceeds from exercise of options													$ 66,000	$ 70,000	$ 39,000
Aggregate fair value of vested stock options													$ 277,000	4,000	36,000
Number of restricted stock units vested during period													333,250
Number of restricted stock units forfeited during period													108,000
Payment of withholding tax related to stock options exercised													$ 23,906	$ 130,537	$ 659,018
Unrecognized compensation expense, Nonvested awards	$ 1,100,000												$ 1,100,000
Unrecognized compensation cost, Period for Recognition													1 year 7 months 6 days
Unvested Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of restricted stock units vested during period	120,000				15,000			100,000		85,000	560,000	100,000	333,250	216,250	745,000
Aggregate fair value of restricted stock vested	$ 193,000				$ 19,000			$ 205,000		$ 224,000	$ 1,800,000	$ 310,000	$ 511,000	$ 387,000	$ 2,300,000
Number of restricted stock units forfeited during period	27,000	61,000	20,000			125,000	175,000		29,250
Aggregate fair value of restricted stock units forfeited during period	$ 50,000	$ 107,000	$ 25,000			$ 166,000	$ 278,000		$ 83,000
Unvested Restricted Stock [Member] \| Milestone Achieved [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of restricted stock units vested during period					40,000
Aggregate fair value of restricted stock vested					$ 52,000
Number of restricted stock units forfeited during period				20,000
Aggregate fair value of restricted stock units forfeited during period				$ 32,000
Unvested Restricted Stock [Member] \| Employees [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of restricted stock units vested during period	193,250
Aggregate fair value of restricted stock vested	$ 286,000
Unvested Restricted Stock [Member] \| Non-Employee Directors[Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of restricted stock units vested during period					61,250
Aggregate fair value of restricted stock vested					$ 111,000