Summary of Preliminary Purchase Price Allocation (Detail) (USD $) In Thousands, unless otherwise specified	9 Months Ended	12 Months Ended			0 Months Ended		0 Months Ended		0 Months Ended		0 Months Ended		0 Months Ended
	Sep. 30, 2014	Dec. 31, 2013	Sep. 30, 2013	Dec. 31, 2012	Aug. 01, 2014 Wise Brother Media Inc	Aug. 01, 2014 Wise Brother Media Inc	Dec. 31, 2013 Green Bay Purchase	Dec. 31, 2013 Green Bay Purchase	Dec. 12, 2013 WestwoodOne Acquisition	Dec. 12, 2013 WestwoodOne Acquisition	Jan. 08, 2013 WFME Asset Exchange	Jan. 08, 2013 WFME Asset Exchange	Jan. 17, 2013 Pamal Broadcasting Asset Purchase	Jan. 17, 2013 Pamal Broadcasting Asset Purchase
Business Acquisition [Line Items]
Current assets										$ 91,171		$ 1,460
Property and equipment						50		1,111		23,714		62		783
Deferred income taxes						100
Other intangible assets						5,500
Broadcast licenses								4,354		150,900
Goodwill	1,255,519	1,256,741	1,204,953	1,195,594				2,637		104,912		11,461
Broadcast licenses	0	61,730									27,100		5,700
Other assets										4,946
Current liabilities						(75)				(69,144)
Other liabilities						(75)				(46,499)
Total purchase price					5,500		17,600				40,083		6,483
Less: Cash consideration									(45,000)		(40,000)
Less: Carrying value of station transferred												(52)
Less: Contingent consideration												(31)
Fair value of exercised put option								9,534
Total purchase price						5,500		17,636		260,000
Gain on asset exchange												$ 0