Goodwill and Intangibles, Net, Measured on Non-Recurring Basis Using Market Approach (Detail) (Fair Value, Measurements, Nonrecurring, Fair Value, Inputs, Level 3, USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Fair Value, Measurements, Nonrecurring | Fair Value, Inputs, Level 3
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Goodwill (annual impairment assessment)	$ 264,186	$ 90,466
Acquired intangible assets (periodic assessment, as necessary)	102,325	58,755
Fair Value Assets And Liabilities Measured On Recurring Basis, Total	$ 366,511	$ 149,221