Stock-Based Compensation - Schedule of Stock Option Activity (Details) - $ / shares	3 Months Ended	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2018
Shares
Options outstanding (in shares)	71,321	115,246
Forfeited (in shares)	0	0
Expired (in shares)	0	0
Exercised (in shares)	(4,750)	(48,675)
Options outstanding (in shares)	66,571	66,571
Weighted Average Exercise Price
Options outstanding, weighted average exercise price (in dollars per share)	$ 19.59	$ 20.73
Forfeited, weighted average exercise price (in dollars per share)	0.00	0.00
Expired, weighted average exercise price (in dollars per share)	0.00	0.00
Exercised, weighted average exercise price (in dollars per share)	24.26	22.74
Options outstanding, weighted average exercise price (in dollars per share)	19.26	19.26
Weighted Average Grant Date Fair Value
Options outstanding, weighted average grant date fair value (in dollars per share)	4.75	4.86
Forfeited, weighted average grant date fair value (in dollars per share)	0.00	0.00
Expired, weighted average grant date fair value (in dollars per share)	0.00	0.00
Exercised, weighted average grant date fair value (in dollars per share)	5.27	5.05
Options outstanding, weighted average grant date fair value (in dollars per share)	$ 4.71	$ 4.71