Stockholders' Equity - Summary of Option Activity under 2010 Plan and 2013 Plan (Details) - USD ($)	3 Months Ended		12 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Options
Number of Shares, Options outstanding at beginning of period	463,600
Number of Shares, Options granted	62,500	0
Number of Shares, Options outstanding at end of period	526,100		463,600
Number of Shares, Options exercisable at end of period	141,134
Weighted Average Exercise Price, Options
Weighted Average Exercise Price, Options outstanding at beginning of period	$ 11.23
Weighted Average Exercise Price, Options granted	17.92
Weighted Average Exercise Price, Options outstanding at end of period	12.31		$ 11.23
Weighted Average Exercise Price, Options exercisable at end of period	$ 3.62
Weighted Average Remaining Contract Term, Options
Weighted Average Remaining Contractual Term, Options outstanding at beginning of period	9 years 2 months 4 days		9 years 6 months
Weighted Average Remaining Contractual Term, Options exercisable at end of period	7 years 10 months 9 days
Aggregate Intrinsic Value, Options outstanding at beginning of period	$ 0
Aggregate Intrinsic Value, Options outstanding at end of period	3,700,000		$ 0
Aggregate Intrinsic Value, Options excersiable at end of period	$ 2,200,000