Business Overview and Liquidity (Details)		3 Months Ended								12 Months Ended
	Mar. 15, 2017 USD ($) employee	Dec. 31, 2016 USD ($)	Sep. 30, 2016 USD ($)	Jun. 30, 2016 USD ($)	Mar. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	Sep. 30, 2015 USD ($)	Jun. 30, 2015 USD ($)	Mar. 31, 2015 USD ($)	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)
Subsequent Event [Line Items]
Cumulative net losses attributed to common stockholders		$ (148,115,202)				$ (108,887,243)				$ (148,115,202)	$ (108,887,243)
Net cash used in operating activities										31,039,855	22,119,025	$ 12,727,385
Net loss and comprehensive loss attributable to common stockholders		8,554,000	$ 10,197,000	$ 10,208,000	$ 10,269,000	7,387,000	$ 2,742,000	$ 10,186,000	$ 7,180,000	39,227,959	27,495,334	14,348,499
Net cash provided by financing activities										2,301,376	64,551,740	14,484,036
Pre-tax expense reduction		$ 9,850,000	$ 10,013,000	$ 10,084,000	$ 10,579,000	$ 7,463,000	$ 6,467,000	$ 6,682,000	$ 4,975,000	$ 40,526,683	$ 25,586,464	$ 15,225,337
Subsequent Event [Member]
Subsequent Event [Line Items]
Pre-tax expense reduction	$ 8,000,000
Reduction of employees | employee	30