Stock-Based Compensation (Details 2) - $ / shares	6 Months Ended
	Jun. 30, 2017	Dec. 31, 2016	Jun. 30, 2016	Dec. 31, 2015
Stock options outstanding (in shares)	152,769	216,859	270,434	298,740
Outstanding options, weighted-average exercise price (in dollars per share)	$ 9.36	$ 8.80	$ 9.85	$ 9.97
Outstanding options, weighted-average remaining contractual life (Year)	1 year 9 months 18 days
Stock options exercisable (in shares)	110,036
Exercisable options, weighted-average exercise price (in dollars per share)	$ 8.06
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)	101,405
Outstanding options, weighted-average exercise price (in dollars per share)	$ 5.76
Outstanding options, weighted-average remaining contractual life (Year)	1 year 6 months 11 days
Stock options exercisable (in shares)	66,707
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)	1 year 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 3 months 7 days
Stock options exercisable (in shares)	1,565
Exercisable options, weighted-average exercise price (in dollars per share)	$ 22.64
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 7 months 13 days
Stock options exercisable (in shares)	375
Exercisable options, weighted-average exercise price (in dollars per share)	$ 49.91