Stockholders' Equity - Follow-on Public Offering (Details) - Follow On Public Offering - USD ($)	May 02, 2017	Jan. 19, 2017	Apr. 26, 2017
Class of Stock [Line Items]
Shelf registration to sell shares		$ 100,000,000
Shares sold by shareholders (shares)	9,200,000
Common Stock
Class of Stock [Line Items]
Shelf registration to sell shares (shares)		20,000,000
Underwriting agreement to sell (shares)			1,150,000
Stock price (in dollars per share)			$ 16.50
Shares sold	1,150,000
Net proceeds	$ 17,400,000
Underwriting discounts and commissions and offering costs	$ 1,600,000