Stockholders' Equity - Narrative (Details)			12 Months Ended
	Nov. 18, 2015 USD ($)	Jul. 31, 2015 USD ($) director $ / shares shares	Dec. 31, 2018 vote $ / shares shares	Dec. 31, 2016 USD ($)	Nov. 17, 2016 USD ($) shares	Dec. 31, 2015 shares	Dec. 31, 2017 $ / shares shares	Feb. 28, 2014 shares
Stockholders' Equity
Authorized common stock (in shares)			400,000,000				400,000,000
Par value of common stock (in dollars per share) | $ / shares			$ 0.0001				$ 0.0001
Number of votes entitled by holders of common stock for each share of common stock | vote			1
Common stock, shares issued (in shares)			50,410,192				50,340,853
Number of shares issuable upon exercise of warrants (in shares)			15,983,072
Exercise price (in dollars per share) | $ / shares			$ 11.50
Number of warrants outstanding (in shares)			15,983,072
Aggregate value of publicly-traded shares of common stock that is authorized to be repurchased | $	$ 10,000,000
Effective period of the repurchase program	1 year
Stock repurchased (in shares)					661,381
Stock repurchased | $				$ 1,488,000	$ 3,900,000
Rohm and Haas
Stockholders' Equity
Number of shares of Series A Preferred Stock issued as condition to consummation of business combination (in shares)		1
Number of directors preferred stockholder is entitled to appoint if minimum ownership percentage of common stock is maintained | director		1
Minimum percentage of outstanding shares of voting and non-voting common stock to be held to entitle preferred stockholder to appoint director		10.00%
Public offering
Stockholders' Equity
Number of warrants outstanding (in shares)								9,823,072
Number of warrants repurchased (in shares)						1,201,928
Private placement
Stockholders' Equity
Number of warrants outstanding (in shares)								6,160,000
Number of shares issued (in shares)		4,878,048
Issue price of stock (in dollars per share) | $ / shares		$ 10.25
Value of shares issued | $		$ 50,000,000