Restructuring Costs - accruals (Details) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Balance at beginning of period	$ 46,600	$ 1,300,000	$ 0
Charges during the period	(15,800)	134,000	5,400,000
Amounts paid during the period	(30,800)	(1,387,400)	(4,100,000)
Balance at end of period	0	46,600	1,300,000
Employee And Contract Termination
Balance at beginning of period	0	0	0
Charges during the period	0	0	1,300,000
Amounts paid during the period	0	0	(1,300,000)
Balance at end of period	0	0	0
Proceed Trial Termination
Balance at beginning of period	46,600	1,300,000	0
Charges during the period	(15,800)	134,000	4,100,000
Amounts paid during the period	(30,800)	(1,387,400)	(2,800,000)
Balance at end of period	$ 0	$ 46,600	$ 1,300,000