Income Taxes - Additional Information (Detail) (USD $)	3 Months Ended	12 Months Ended
	Sep. 30, 2013	Dec. 31, 2013	Dec. 31, 2012
Operating Loss Carryforwards [Line Items]
Deferred tax asset valuation allowance		$ 27,673,000	$ 24,102,000
Increase in valuation allowance	2,200,000	3,600,000
Tax credit carryforwards		2,700,000
Period of increase in ownership percentage		3 years
Domestic Tax Authority [Member]
Operating Loss Carryforwards [Line Items]
Net operating loss carryforward		55,600,000
Expired state net operating losses		3,300,000
State and Local Jurisdiction [Member]
Operating Loss Carryforwards [Line Items]
Net operating loss carryforward		9,300,000
Federal and state net operating loss carryforwards		$ 42,500,000
Federal net operating loss carryforwards expiry date		$42.5 million will expire in 2022 and 2023