Shareholders' Equity - Controlled Equity Offering (Details) - USD ($)			3 Months Ended		12 Months Ended
	Apr. 22, 2013	Apr. 18, 2013	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2015	Dec. 31, 2016	Jan. 19, 2016
Class of Stock [Line Items]
Common stock aggregate offering price			$ 345			$ 344
Proceeds from the issuance of common stock through controlled equity offering			0	$ 264,668
Cantor Fitzgerald And Company | The Sales Agreement
Class of Stock [Line Items]
Common stock authorized for sale		$ 25,000,000					$ 15,081,494
Commission rate		3.00%
Common stock issued (in shares)	264,831
Stock offering, maximum public float							$ 75,000,000
Proceeds from the issuance of common stock through controlled equity offering				$ 691,187
Recovery of deferred offering costs					$ 48,977
Value of common stock available for sale under agreement			$ 14,300,000
Cantor Fitzgerald And Company | The Sales Agreement | Common Stock
Class of Stock [Line Items]
Common stock issued (in shares)				77,141
Cantor Fitzgerald And Company | The Sales Agreement | Offer and Sale
Class of Stock [Line Items]
Common stock aggregate offering price		$ 17,000,000