Common Stock and Share-Based Compensation - Stock Option Activity (Details)	9 Months Ended
	Sep. 30, 2018 USD ($) $ / shares shares
Options
Options outstanding at beginning of period (shares) | shares	700,467
Forfeited and canceled (shares) | shares	(299,914)
Exercised (shares) | shares	0
Options outstanding at end of period (shares) | shares	400,553
Weighted Average Exercise Price
Options outstanding at beginning of period (USD per share) | $ / shares	$ 17.21
Forfeited and canceled (USD per share) | $ / shares	20.61
Exercised (USD per share) | $ / shares	0.00
Options outstanding at end of period (USD per share) | $ / shares	$ 14.65
Options outstanding and exercisable at end of period - Weighted average contractual life	1 year 3 months 4 days
Options outstanding and exercisable at end of period - Aggregate intrinsic value | $	$ 0