Stock Incentive Plan - Narrative (Details) - USD ($)	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares of authorized stock for stock incentive plan (in shares)	350,000
Stock-based compensation expense	$ 253,000	$ 128,000
Stock options exercised (in shares)	0
Shares issued upon exercise of stock options (in shares)		11,975
Proceeds from stock option exercises		$ 0
Shares withheld for stock option exercises and related income taxes, amount withheld		$ 932,000
Options granted (in shares)	0	0
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share based compensation options contractual term	10 years
Stock incentive plan vesting period, years	3 years
Stock-based compensation expense	$ 76,000	$ 32,000
Cashless Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Proceeds from stock option exercises		800,000
Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock incentive plan vesting period, years	3 years
Stock-based compensation expense	$ 177,000	$ 96,000
Restricted units granted (in shares)	0	0