Stock-Based Compensation (Details 2) - $ / shares	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
$0.79 to $1.00
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options Outstanding, Exercise Price Range, Lower Range Limit (in dollars per share)	$ 0.79	$ 0.79
Options Outstanding, Exercise Price Range, Upper Range Limit (in dollars per share)	$ 1.00	$ 1.00
Options Outstanding, Number of Options (in shares)	50,000	50,000
Options Outstanding, Weighted Average Remaining Contractual Term	3 years 4 days	4 years 4 days
Options Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 0.79	$ 0.79
Options Exercisable, Number of Options (in shares)	50,000	50,000
Options Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 0.79	$ 0.79
1.01 to 1.50
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options Outstanding, Exercise Price Range, Lower Range Limit (in dollars per share)	1.01	1.01	$ 1.01
Options Outstanding, Exercise Price Range, Upper Range Limit (in dollars per share)	$ 1.50	$ 1.50	$ 1.50
Options Outstanding, Number of Options (in shares)	1,808,400	1,862,400	1,887,500
Options Outstanding, Weighted Average Remaining Contractual Term	5 years 1 month 11 days	6 years 1 month 20 days	7 years 1 month 20 days
Options Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 1.07	$ 1.07	$ 1.07
Options Exercisable, Number of Options (in shares)	1,808,400	1,851,400	1,448,664
Options Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 1.07	$ 1.07	$ 1.08
1.51 to 10.67
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options Outstanding, Exercise Price Range, Lower Range Limit (in dollars per share)	1.51	1.51
Options Outstanding, Exercise Price Range, Upper Range Limit (in dollars per share)	$ 10.67	$ 10.67
Options Outstanding, Number of Options (in shares)	2,246,969	1,680,334
Options Outstanding, Weighted Average Remaining Contractual Term	8 years 3 months 35 days	8 years 11 months 16 days
Options Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 7.82	$ 8.10
Options Exercisable, Number of Options (in shares)	805,803	289,997
Options Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 7.15	$ 4.02
$0.79 to $10.67
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options Outstanding, Exercise Price Range, Lower Range Limit (in dollars per share)	0.79	0.79
Options Outstanding, Exercise Price Range, Upper Range Limit (in dollars per share)	$ 10.67	$ 10.67
Options Outstanding, Number of Options (in shares)	4,105,369	3,592,734
Options Outstanding, Weighted Average Remaining Contractual Term	6 years 8 months 70 days	7 years 5 months 5 days
Options Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 4.76	$ 4.36
Options Exercisable, Number of Options (in shares)	2,664,203	2,191,397
Options Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 2.90	$ 1.45
$0.76 to $1.00
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options Outstanding, Exercise Price Range, Lower Range Limit (in dollars per share)			0.76
Options Outstanding, Exercise Price Range, Upper Range Limit (in dollars per share)			$ 1.00
Options Outstanding, Number of Options (in shares)			97,000
Options Outstanding, Weighted Average Remaining Contractual Term			3 years 14 days
Options Outstanding, Weighted Average Exercise Price (in dollars per share)			$ 0.78
Options Exercisable, Number of Options (in shares)			97,000
Options Exercisable, Weighted Average Exercise Price (in dollars per share)			$ 0.78
1.51 to 10.55
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options Outstanding, Exercise Price Range, Lower Range Limit (in dollars per share)			1.51
Options Outstanding, Exercise Price Range, Upper Range Limit (in dollars per share)			$ 10.55
Options Outstanding, Number of Options (in shares)			452,334
Options Outstanding, Weighted Average Remaining Contractual Term			8 years 8 months 5 days
Options Outstanding, Weighted Average Exercise Price (in dollars per share)			$ 5.02
Options Exercisable, Number of Options (in shares)			110,333
Options Exercisable, Weighted Average Exercise Price (in dollars per share)			$ 1.78
$0.76 to $10.55
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options Outstanding, Exercise Price Range, Lower Range Limit (in dollars per share)			0.76
Options Outstanding, Exercise Price Range, Upper Range Limit (in dollars per share)			$ 10.55
Options Outstanding, Number of Options (in shares)			2,436,834
Options Outstanding, Weighted Average Remaining Contractual Term			7 years 3 months 4 days
Options Outstanding, Weighted Average Exercise Price (in dollars per share)			$ 1.79
Options Exercisable, Number of Options (in shares)			1,655,997
Options Exercisable, Weighted Average Exercise Price (in dollars per share)			$ 1.11