Stock-Based Compensation (Details 2) - $ / shares	9 Months Ended
	Sep. 30, 2017	Dec. 31, 2016	Sep. 30, 2016	Dec. 31, 2015
Stock options outstanding (in shares)	152,439	216,859	269,545	298,740
Outstanding options, weighted-average exercise price (in dollars per share)	$ 9.36	$ 8.80	$ 10.03	$ 9.97
Outstanding options, weighted-average remaining contractual life (Year)	1 year 6 months 14 days
Stock options exercisable (in shares)	110,581
Exercisable options, weighted-average exercise price (in dollars per share)	$ 8.28
Range 1 [Member]
Outstanding options, exercise price range, lower limit (in dollars per share)	5.76
Outstanding options, exercise price range, upper limit (in dollars per share)	$ 10.72
Stock options outstanding (in shares)	101,075
Outstanding options, weighted-average exercise price (in dollars per share)	$ 5.76
Outstanding options, weighted-average remaining contractual life (Year)	1 year 3 months 4 days
Stock options exercisable (in shares)	66,377
Exercisable options, weighted-average exercise price (in dollars per share)	$ 5.76
Range 2 [Member]
Outstanding options, exercise price range, lower limit (in dollars per share)	10.73
Outstanding options, exercise price range, upper limit (in dollars per share)	$ 11.40
Stock options outstanding (in shares)	41,389
Outstanding options, weighted-average exercise price (in dollars per share)	$ 10.84
Outstanding options, weighted-average remaining contractual life (Year)	9 months 7 days
Stock options exercisable (in shares)	41,389
Exercisable options, weighted-average exercise price (in dollars per share)	$ 10.84
Range 3 [Member]
Outstanding options, exercise price range, lower limit (in dollars per share)	11.41
Outstanding options, exercise price range, upper limit (in dollars per share)	$ 24.86
Stock options outstanding (in shares)	3,225
Outstanding options, weighted-average exercise price (in dollars per share)	$ 22.79
Outstanding options, weighted-average remaining contractual life (Year)	6 years 7 days
Stock options exercisable (in shares)	2,065
Exercisable options, weighted-average exercise price (in dollars per share)	$ 23.18
Range 4 [Member]
Outstanding options, exercise price range, lower limit (in dollars per share)	24.87
Outstanding options, exercise price range, upper limit (in dollars per share)	$ 49.91
Stock options outstanding (in shares)	6,750
Outstanding options, weighted-average exercise price (in dollars per share)	$ 47.83
Outstanding options, weighted-average remaining contractual life (Year)	8 years 4 months 13 days
Stock options exercisable (in shares)	750
Exercisable options, weighted-average exercise price (in dollars per share)	$ 49.49