Equity (Details) - USD ($)		1 Months Ended	12 Months Ended
	Jul. 27, 2015	Jan. 31, 2016	Dec. 31, 2016	Dec. 31, 2015	Jul. 31, 2016	Jun. 30, 2016
Class of Stock [Line Items]
Proceeds from public offering, gross	$ 17,300,000
Proceeds from public offering, net	$ 15,900,000		$ 0	$ 15,872,000
Common stock, shares authorized (in shares)			150,000,000	100,000,000	150,000,000	100,000,000
Preferred stock authorized for issuance (shares)			5,000,000
Preferred shares issued (in shares)			0	0
Preferred shares outstanding (in shares)			0	0
Cantor Fitzgerald & Co.
Class of Stock [Line Items]
Commission as a percent of gross proceeds		3.00%
Common Stock
Class of Stock [Line Items]
Underwritten public offering (shares)	2,586,206
Common stock issued (usd per share)	$ 5.80
Common Stock | Cantor Fitzgerald & Co.
Class of Stock [Line Items]
Underwritten public offering (shares)			159,841
Proceeds from public offering, net			$ 0
Aggregate offering price		$ 50,000,000.0
Common Stock | Over-Allotment Option
Class of Stock [Line Items]
Underwritten public offering (shares)	387,930