Stockholders' Equity (Narrative) (Details) (USD $)	0 Months Ended	3 Months Ended								3 Months Ended				3 Months Ended		0 Months Ended			3 Months Ended
	Sep. 24, 2013	Mar. 31, 2014 employee	Mar. 31, 2014 Stock Option	Mar. 31, 2014 Restricted Stock	Mar. 31, 2014 Restricted Stock Research and development	Mar. 31, 2014 Restricted Stock General and administrative	Mar. 31, 2014 Common Stock	Mar. 31, 2014 Series C-1 Preferred Stock	Dec. 31, 2013 Series C-1 Preferred Stock	Mar. 31, 2014 Series C-1 Preferred Stock Common Stock	Mar. 31, 2014 Series D-1 Preferred Stock Common Stock	Mar. 31, 2014 Series F Preferred Stock	Dec. 31, 2013 Series F Preferred Stock	Mar. 31, 2014 Consultant Restricted Stock	Mar. 31, 2014 Consultant Common Stock	Sep. 24, 2013 2013 Equity Plan	Mar. 31, 2014 2013 Equity Plan	Jan. 02, 2014 2013 Equity Plan	Mar. 31, 2014 One-year Anniversary Date of Grant	Mar. 31, 2014 Quarterly
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares of common stock issued							2,852,626			2,797,029	52,621			2,976	2,976
Preferred stock, shares authorized		8,000,000						11,000	11,000			10,000	10,000
Preferred stock, par value		$ 0.0001						$ 0.0001	$ 0.0001			$ 0.0001	$ 0.0001
Preferred stock, shares issued								5,393	7,016			3,066	3,250
Equity plan, term	10 years
Automatic annual increase based on outstanding shares of Common Stock as of the last day of the previous year end, percent																10.00%
Shares available for grant																	367,441	422,441
Number of employees granted stock options		5
Options Granted, Number of Shares		55,000
Award vesting rights, percentage																			25.00%
Period of share-based payment awards																				3 years
Options Granted, Weighted-Average Exercise Price		$ 7.51
Unamortized share-based compensation expense			$ 600,000
Recognized weighted average period			44 months		22 months	32 months
Shares canceled				39,811
Unamortized share-based compensation expense					$ 2,189,000	$ 11,384,000