Depreciation and Amortization - Depreciation and Amortization Expense Excluded from Operating Expenses and Statements of Operations (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Component Of Other Income And Expense [Line Items]
Depreciation and amortization	$ 62,675	$ 73,183	$ 203,250	$ 219,492
Direct advertising expenses [Member]
Component Of Other Income And Expense [Line Items]
Depreciation and amortization	58,562	69,040	191,100	207,265
General and administrative expenses [Member]
Component Of Other Income And Expense [Line Items]
Depreciation and amortization	1,082	1,151	3,183	2,921
Corporate expenses [Member]
Component Of Other Income And Expense [Line Items]
Depreciation and amortization	$ 3,031	$ 2,992	$ 8,967	$ 9,306