Accrued Liabilities (Details) - USD ($)	Sep. 30, 2017	Dec. 31, 2016
Accrued Liabilities [Abstract]
Salaries, employee benefits and related taxes	$ 1,169,600	$ 1,406,300
Retention payments	2,233,000	0
Professional fees	367,300	224,500
Income tax payable	4,075,600	0
CIRM upfront funding - current	1,745,500	0
Other	544,700	1,028,600
Total accrued liabilities	$ 10,135,700	$ 2,659,400