Property and Equipment, Net - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Property, Plant and Equipment [Line Items]
Depreciation expense	$ 12,644	$ 12,867	$ 25,644	$ 25,649