Consolidated Balance Sheets - USD ($)	Mar. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Current assets:
Cash and cash equivalents	$ 2,822,677	$ 3,444,952	$ 12,583,764
Other current assets	237,331	371,562	498,798
Total current assets	3,060,008	3,816,514	13,082,562
Property & equipment, net	0	50,000	837,867
Other long-term assets		0	496,269
Total assets	3,060,008	3,866,514	14,416,698
Current liabilities:
Accounts payable	298,050	377,956	739,850
Accrued expenses	428,394	625,890	1,008,077
Deferred revenue.		0	2,905,165
Notes payable - insurance	91,871	156,642	148,344
Total current liabilities	818,315	1,160,488	4,801,436
Total liabilities	818,315	1,160,488	4,801,436
Shareholders' equity:
Preferred stock	0	0	0
Common stock	76,573	71,411	69,829
Additional paid in capital	164,410,992	163,954,215	162,884,919
Accumulated deficit	(162,245,872)	(161,319,600)	(153,339,486)
Total shareholders' equity	2,241,693	2,706,026	9,615,262
Total liabilities and shareholders' equity	$ 3,060,008	$ 3,866,514	$ 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).

Name:	us-gaap_AccountsPayableCurrent
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).