Income Taxes - Additional Information (Detail) (USD $)	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013	Mar. 31, 2013
Deferred Tax Assets Liabilities [Line Items]
Tax benefit recognized	$ 0		$ 0
Benefit for income taxes	(527,000)	(406,000)	(510,000)	(6,337,000)
Federal research tax credit						549,000
Valuation allowance, deferred tax assets	20,179,000		20,179,000
Deferred tax assets valuation allowance increase					10,241,000
Expected cash refunds to be generated	1,600,000		1,600,000
Internal Revenue Service [Member]
Deferred Tax Assets Liabilities [Line Items]
Benefit for income taxes	(552,000)
Net tax benefit refunded from completion of examination	$ 17,000		$ 17,000