Summary of Significant Accounting Policies - Schedule of Earnings Per Share, Basic and Diluted (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Numerator:
Net income (loss) attributable to common stockholders	$ 17,929	$ (6,439)	$ (12,602)
Denominator:
Weighted average common shares outstanding, basic (in shares)	25,353,966	22,837,263	22,548,932
Weighted average common shares outstanding, diluted (in shares)	26,269,727	22,837,263	22,548,932
Basic (in dollars per share)	$ 0.71	$ (0.28)	$ (0.56)
Diluted (in dollars per share)	$ 0.68	$ (0.28)	$ (0.56)
Antidilutive securities (in shares)	5,135,558	1,792,607	1,919,542
Restricted stock units
Denominator:
Antidilutive securities (in shares)	438,712
Stock Options
Denominator:
Antidilutive securities (in shares)	477,048