Consolidated Balance Sheets - USD ($)	Mar. 31, 2016	Dec. 31, 2015
Current assets:
Cash and cash equivalents	$ 9,955,449	$ 12,583,764
Other current assets	932,409	995,067
Total current assets	10,887,858	13,578,831
Property & equipment, net of accumulated depreciation of $2,516,189 and $2,443,600, respectively	765,763	837,867
Total assets	11,653,621	14,416,698
Current liabilities:
Accounts payable	562,218	739,850
Accrued expenses	1,210,608	1,008,077
Deferred revenue	2,178,874	2,905,165
Notes payable - insurance	93,200	148,344
Total current liabilities	4,044,900	4,801,436
Long term liabilities:
Total liabilities	4,044,900	4,801,436
Stockholders' equity:
Preferred stock, no par value, 10,000,000 shares authorized, none issued and outstanding	0	0
Common stock, $0.01 par value, 150,000,000 shares authorized, 6,982,909 and 6,982,909 shares issued and outstanding	69,829	69,829
Additional paid in capital	163,038,772	162,884,919
Accumulated deficit	(155,499,880)	(153,339,486)
Total stockholders' equity	7,608,721	9,615,262
Total liabilities and stockholders' equity	$ 11,653,621	$ 14,416,698

Carrying value as of the balance sheet date of liabilities incurred (and for which invoices have typically been received) and payable to vendors for goods and services received that are used in an entity's business. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Carrying value as of the balance sheet date of obligations incurred and payable, pertaining to costs that are statutory in nature, are incurred on contractual obligations, or accumulate over time and for which invoices have not yet been received or will not be rendered. Examples include taxes, interest, rent and utilities. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).