Commitments and Contingencies - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Contingencies And Commitments [Line Items]
Lease expense	$ 100,000	$ 100,000	$ 100,000
Lease term	89 months
CDC [Member]
Contingencies And Commitments [Line Items]
Royalties received	18,750
Granted royalty on sales of the next BEMA product	1.00%
Net sales of next BEMA Product	7,500,000
Minimum [Member] | CDC [Member]
Contingencies And Commitments [Line Items]
Royalties received	$ 375,000