Stockholders' Equity - Stock Options Outstanding and Exercisable (Details)	12 Months Ended
	Dec. 31, 2016 $ / shares shares
Range One
Stock options outstanding and exercisable
Range of Exercise Prices, Lower Range Limit	$ 3.46
Range of Exercise Prices, Upper Range Limit	$ 3.92
Options Outstanding, Number of Shares | shares	47,935
Options Outstanding, Weighted Average Remaining Contractual Life (years)	2 years 2 months 5 days
Options Outstanding, Weighted Average Exercise Price	$ 3.84
Options Vested and Exercisable, Number of Shares Exercisable | shares	47,164
Options Vested and Exercisable, Weighted Average Exercise Price	$ 3.84
Range Two
Stock options outstanding and exercisable
Range of Exercise Prices, Lower Range Limit	3.95
Range of Exercise Prices, Upper Range Limit	$ 5.92
Options Outstanding, Number of Shares | shares	73,182
Options Outstanding, Weighted Average Remaining Contractual Life (years)	2 years 10 months 13 days
Options Outstanding, Weighted Average Exercise Price	$ 5.01
Options Vested and Exercisable, Number of Shares Exercisable | shares	60,241
Options Vested and Exercisable, Weighted Average Exercise Price	$ 4.86
Range Three
Stock options outstanding and exercisable
Range of Exercise Prices, Lower Range Limit	6.00
Range of Exercise Prices, Upper Range Limit	$ 8.16
Options Outstanding, Number of Shares | shares	82,169
Options Outstanding, Weighted Average Remaining Contractual Life (years)	5 years 2 months 9 days
Options Outstanding, Weighted Average Exercise Price	$ 7.38
Options Vested and Exercisable, Number of Shares Exercisable | shares	35,615
Options Vested and Exercisable, Weighted Average Exercise Price	$ 7.08
Range Four
Stock options outstanding and exercisable
Range of Exercise Prices, Lower Range Limit	8.29
Range of Exercise Prices, Upper Range Limit	$ 8.58
Options Outstanding, Number of Shares | shares	60,799
Options Outstanding, Weighted Average Remaining Contractual Life (years)	4 years 2 months 1 day
Options Outstanding, Weighted Average Exercise Price	$ 8.45
Options Vested and Exercisable, Number of Shares Exercisable | shares	38,325
Options Vested and Exercisable, Weighted Average Exercise Price	$ 8.45
Range Five
Stock options outstanding and exercisable
Range of Exercise Prices, Lower Range Limit	8.60
Range of Exercise Prices, Upper Range Limit	$ 10.33
Options Outstanding, Number of Shares | shares	59,500
Options Outstanding, Weighted Average Remaining Contractual Life (years)	4 years 11 months 16 days
Options Outstanding, Weighted Average Exercise Price	$ 9.39
Options Vested and Exercisable, Number of Shares Exercisable | shares	27,067
Options Vested and Exercisable, Weighted Average Exercise Price	$ 9.10
Range Six
Stock options outstanding and exercisable
Range of Exercise Prices, Lower Range Limit	10.45
Range of Exercise Prices, Upper Range Limit	$ 10.45
Options Outstanding, Number of Shares | shares	400
Options Outstanding, Weighted Average Remaining Contractual Life (years)	5 years 2 months 1 day
Options Outstanding, Weighted Average Exercise Price	$ 10.45
Options Vested and Exercisable, Number of Shares Exercisable | shares	200
Options Vested and Exercisable, Weighted Average Exercise Price	$ 10.45
Range Seven
Stock options outstanding and exercisable
Range of Exercise Prices, Lower Range Limit	10.73
Range of Exercise Prices, Upper Range Limit	$ 10.73
Options Outstanding, Number of Shares | shares	61,223
Options Outstanding, Weighted Average Remaining Contractual Life (years)	5 years 1 month 24 days
Options Outstanding, Weighted Average Exercise Price	$ 10.73
Options Vested and Exercisable, Number of Shares Exercisable | shares	26,098
Options Vested and Exercisable, Weighted Average Exercise Price	$ 10.73
Range Eight
Stock options outstanding and exercisable
Range of Exercise Prices, Lower Range Limit	11.04
Range of Exercise Prices, Upper Range Limit	$ 11.04
Options Outstanding, Number of Shares | shares	15,800
Options Outstanding, Weighted Average Remaining Contractual Life (years)	5 years 2 months 1 day
Options Outstanding, Weighted Average Exercise Price	$ 11.04
Options Vested and Exercisable, Number of Shares Exercisable | shares	885
Options Vested and Exercisable, Weighted Average Exercise Price	$ 11.04
Range Nine
Stock options outstanding and exercisable
Range of Exercise Prices, Lower Range Limit	12.85
Range of Exercise Prices, Upper Range Limit	$ 12.85
Options Outstanding, Number of Shares | shares	32,500
Options Outstanding, Weighted Average Remaining Contractual Life (years)	6 years 9 months 26 days
Options Outstanding, Weighted Average Exercise Price	$ 12.85
Options Vested and Exercisable, Number of Shares Exercisable | shares	118
Options Vested and Exercisable, Weighted Average Exercise Price	$ 12.85
Range Ten
Stock options outstanding and exercisable
Range of Exercise Prices, Lower Range Limit	16.29
Range of Exercise Prices, Upper Range Limit	$ 16.29
Options Outstanding, Number of Shares | shares	37,477
Options Outstanding, Weighted Average Remaining Contractual Life (years)	6 years 6 months 26 days
Options Outstanding, Weighted Average Exercise Price	$ 16.29
Options Vested and Exercisable, Number of Shares Exercisable | shares	686
Options Vested and Exercisable, Weighted Average Exercise Price	$ 16.29
Range Eleven
Stock options outstanding and exercisable
Range of Exercise Prices, Lower Range Limit	3.46
Range of Exercise Prices, Upper Range Limit	$ 16.29
Options Outstanding, Number of Shares | shares	470,985
Options Outstanding, Weighted Average Remaining Contractual Life (years)	4 years 6 months 29 days
Options Outstanding, Weighted Average Exercise Price	$ 8.69
Options Vested and Exercisable, Number of Shares Exercisable | shares	236,399
Options Vested and Exercisable, Weighted Average Exercise Price	$ 6.77