Net loss per share - Additional Information (Detail)	0 Months Ended	6 Months Ended
	Feb. 27, 2014	Jun. 30, 2014
Schedule Of Earnings Per Share [Line Items]
Conversion basis for reverse stock split		The Company effected a 1-for-19.2 reverse stock split
Conversion ratio of reverse stock split	0.052083	0.052083
Reorganization [Member]
Schedule Of Earnings Per Share [Line Items]
Common stock outstanding		5,845,260
Options outstanding		628,754
Warrants outstanding		11,363