Stock-Based Compensation (Details 3) - Performance Shares [Member]	12 Months Ended
	Dec. 31, 2017 $ / shares shares
Number of Units (in shares)
Outstanding and unvested, beginning of period | shares	124,394
Granted | shares	104,590
Vested | shares	0
Forfeited | shares	(39,916)
Outstanding and unvested, end of period | shares	189,068
Weighted average grant date fair value
Outstanding and unvested, beginning of period (in dollars per share) | $ / shares	$ 31.08
Granted (in dollars per share) | $ / shares	23.65
Vested (in dollars per share) | $ / shares	0.00
Forfeited (in dollars per share) | $ / shares	27.74
Outstanding and unvested, end of period (in dollars per share) | $ / shares	$ 27.68