Property and Equipment, Net (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Property, Plant and Equipment [Line Items]
Depreciation and amortization expense	$ 123,138	$ 108,629	$ 83,137
Internal-use software
Property, Plant and Equipment [Line Items]
Stock-based compensation capitalized as part of internal-use software	100	100	300
Property and equipment, types
Property, Plant and Equipment [Line Items]
Depreciation and amortization expense	$ 2,000	$ 1,600	$ 1,300