Income Taxes - Additional Information (Detail) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011	Apr. 05, 2012
Income Tax Examination [Line Items]
Income tax (benefit) expenses	$ (298,000)	$ 52,000	$ (550,000)	$ 132,000
Effective income tax rate	3.80%	(1.20%)	2.20%	(0.20%)
Net deferred tax liabilities primarily related to timing differences for the amortization of intangible assets					$ 1,800,000
Federal income tax returns
Income Tax Examination [Line Items]
Income tax examination year			2008
State income tax returns
Income Tax Examination [Line Items]
Income tax examination year			2007