Consolidated Statements of Cash Flows (Parenthetical) - $ / shares	Dec. 31, 2018	Dec. 31, 2017
Supplemental disclosures - non-cash activities:
Common stock, par value	$ 0.01
Milestone obligation [Member]
Supplemental disclosures - non-cash activities:
Common stock, par value		$ 0.01
Payment to Consultant [Member]
Supplemental disclosures - non-cash activities:
Common stock, par value	$ 0.01
SECANT Yeast Display technology [Member]
Supplemental disclosures - non-cash activities:
Common stock, par value		$ 0.01