Stockholders' Equity (Details)	3 Months Ended	12 Months Ended
	Mar. 31, 2017 vote director $ / shares shares	Dec. 31, 2015 shares	Dec. 31, 2016 $ / 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 outstanding (in shares)	50,280,826		50,037,206
Number of shares issuable upon exercise of warrants (in shares)	15,983,072
Exercise price (in dollars per share) | $ / shares	$ 11.5
Number of warrants outstanding (in shares)	15,983,072
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
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