Stockholders' Equity - Schedule of Pre-2017 Non-Qualified Stock Options Nonvested Share Activity (Details)	9 Months Ended
	Sep. 30, 2018 $ / shares shares
Number of Shares
Vested (in shares) | shares	(42,500)
Weighted Average Grant Date Fair Value Per Share
Vested (in dollars per share) | $ / shares	$ 35.01
Pre-2017 Non-Qualified Stock Options
Number of Shares
Non-vested, beginning balance (in shares) | shares	288,902
Vested (in shares) | shares	(126,801)
Non-vested, ending balance (in shares) | shares	162,101
Weighted Average Grant Date Fair Value Per Share
Non-vested, beginning balance (in dollars per share) | $ / shares	$ 7.87
Vested (in dollars per share) | $ / shares	7.93
Non-vested, ending balance (in dollars per share) | $ / shares	$ 7.82