Property and Equipment, Net (Parenthetical) (Detail) (USD $)	3 Months Ended				9 Months Ended			12 Months Ended
	Sep. 30, 2013	Sep. 30, 2012		Jun. 30, 2012	Sep. 30, 2013	Sep. 30, 2012		Dec. 31, 2012
Property Plant And Equipment [Line Items]
Impairment of long-lived assets	$ 325,000	$ 870,000	[1]	$ 23,900,000	$ 325,000	$ 24,785,000	[1]	$ 24,785,000
Asset impairment					50,000
Software
Property Plant And Equipment [Line Items]
Impairment of long-lived assets	$ 200,000

[1] Certain amounts shown in the table above have changed as compared to amounts reported in prior periods as noted in Item 1, Financial Statements, Note 1 of Notes to Condensed Consolidated Financial Statements, Reclassifications and Restatements.