Subsequent Events - Additional Information (Detail) (7.875% Senior Secured Notes, due July 15, 2019 [Member], HGI [Member], USD $)	Jul. 23, 2013	Jun. 30, 2013	Dec. 30, 2012	Sep. 30, 2012
7.875% Senior Secured Notes, due July 15, 2019 [Member] | HGI [Member]
Subsequent Event [Line Items]
Debt Instrument, Face Amount	$ 225,000,000		$ 700,000,000.0
Long-term debt, interest rate	7.875%	7.875%	7.875%
Long-term debt, percentage	101.50%		99.36%