Income Taxes - Additional Information (Detail) (USD $)	3 Months Ended		9 Months Ended		12 Months Ended	1 Months Ended	12 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012	Jan. 31, 2013 Income Taxes	Dec. 31, 2012 Federal	Dec. 31, 2012 California	Dec. 31, 2012 California Minimum	Dec. 31, 2012 California Maximum
Income Taxes [Line Items]
Income tax expense (benefit)	$ (7,000)	$ (60,000)	$ 86,000	$ 22,000
Net operating loss carry forwards							887,300,000	976,900,000
Net operating loss expiration period							20 years		10 years	20 years
Net operating loss carry forwards expiration year							2027	2017
Deferred tax asset valuation allowance	374,300,000		374,300,000		373,700,000
Income tax refund requested					24,800,000
IRS determined tax liability for 2005 AMT					2,600,000
Company determined tax liability for 2005 AMT					400,000
Accrued interest on company determined tax liability for 2005 AMT					30,000
Payment to IRS			$ 598,000	$ 138,000		$ 400,000