Income Taxes - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009	Dec. 31, 2008
Income Taxes [Line Items]
Income tax provision, federal rate	35.00%	35.00%	35.00%
Unrecognized tax benefit	$ 1,180,000	$ 1,180,000	$ 1,180,000	$ 1,180,000
State Jurisdiction
Income Taxes [Line Items]
Operating loss carryforwards, decrease in valuation allowance	(4,800,000)
Operating loss carryforwards	173,700,000
State Jurisdiction | Minimum
Income Taxes [Line Items]
Income tax, years under examination	2008
State Jurisdiction | Maximum
Income Taxes [Line Items]
Income tax, years under examination	2011
State and Local Jurisdiction
Income Taxes [Line Items]
Operating loss carryforwards, valuation allowance	12,300,000
Local Jurisdiction
Income Taxes [Line Items]
Operating loss carryforwards	$ 140,800,000
Internal Revenue Service (IRS) | Minimum
Income Taxes [Line Items]
Income tax, years under examination	2008
Internal Revenue Service (IRS) | Maximum
Income Taxes [Line Items]
Income tax, years under examination	2011