Condensed Statements of Convertible Preferred Stock and Stockholders' (Deficit) Equity (USD $) In Thousands, except Share data	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Deficit [Member]	Convertible Preferred Stock [Member]	Beneficial Conversion Feature on Convertible Promissory Notes [Member]
Balance, Value at Dec. 31, 2012					$ 58,522	$ 2,050
Balance, Value at Dec. 31, 2012	(58,133)	3	1,248	(59,384)
Balance, Shares at Dec. 31, 2012					26,636,118
Balance, Shares at Dec. 31, 2012		3,328,698
Issuance of Junior A convertible preferred stock, net, Value					7,642
Issuance of Junior A convertible preferred stock, net, Shares					2,105,263
Preferred stock converted to common shares, Value	4,466	1	3,574	891	(4,466)
Preferred stock converted to common shares, Shares		959,545			(2,246,743)
Beneficial conversion feature on convertible promissory notes						1,382
Reclassification of beneficial conversion feature	2,483		2,483			(2,483)
Stock-based compensation expense	51		51
Net (loss) income	2,705			2,705
Balance, Value at Jun. 30, 2013	(48,428)	4	7,356	(55,788)
Balance, Value at Jun. 30, 2013					61,698	949
Balance, Shares at Jun. 30, 2013		4,288,243
Balance, Shares at Jun. 30, 2013					26,494,638
Balance, Value at Dec. 31, 2013	65,586				65,586
Balance, Value at Dec. 31, 2013	(54,075)	4	8,377	(62,456)
Balance, Shares at Dec. 31, 2013	29,186,929				29,186,929
Balance, Shares at Dec. 31, 2013		4,288,243
Preferred stock converted to common shares, Value	65,586	13	65,573		(65,586)
Preferred stock converted to common shares, Shares		12,554,171			(29,186,929)
Sale of common stock in initial public offering, net of underwriting discounts and commissions and offering expenses, Value	56,247	6	56,241
Sale of common stock in initial public offering, net of underwriting discounts and commissions and offering expenses, Shares		5,750,000
Stock-based compensation expense	809		809
Shares issued upon exercise of stock options, Value	29		29
Shares issued upon exercise of stock options, Shares	46,000	46,000
Net (loss) income	(7,028)			(7,028)
Balance, Value at Jun. 30, 2014	61,568	23	131,029	(69,484)
Balance, Value at Jun. 30, 2014	$ 0				$ 0	$ 0
Balance, Shares at Jun. 30, 2014		22,638,414
Balance, Shares at Jun. 30, 2014	0				0