Acquisitions and Dispositions - Additional Information (Detail) (USD $)	9 Months Ended		0 Months Ended		0 Months Ended		9 Months Ended	12 Months Ended	0 Months Ended	3 Months Ended	9 Months Ended		0 Months Ended	9 Months Ended		0 Months Ended				0 Months Ended
	Sep. 30, 2014 Affiliate Market	Sep. 30, 2013	Aug. 01, 2014 Wise Brother Media Inc	Sep. 30, 2014 Wise Brother Media Inc	Dec. 31, 2013 Green Bay Purchase Station	Apr. 10, 2009 Green Bay Purchase Station	Sep. 30, 2014 Green Bay Purchase	Dec. 31, 2013 Green Bay Purchase Station	Dec. 12, 2013 WestwoodOne Acquisition	Sep. 30, 2014 WestwoodOne Acquisition	Sep. 30, 2014 WestwoodOne Acquisition	Dec. 12, 2013 WestwoodOne Acquisition Station	Nov. 14, 2013 Townsquare Transaction Station Market	Sep. 30, 2014 Townsquare Transaction	Nov. 14, 2013 Townsquare Transaction Market	Jan. 08, 2013 WFME Asset Exchange	Jan. 08, 2013 WFME Asset Exchange	Sep. 30, 2014 WFME Asset Exchange Maximum	Dec. 31, 2013 WFME Asset Exchange Maximum	Jan. 17, 2013 Pamal Broadcasting Asset Purchase
Business Acquisition [Line Items]
Number of radio stations acquired					5	5		5					5
Total purchase price			$ 5,500,000		$ 17,600,000											$ 40,083,000				$ 6,483,000
Revenue growth rates (percentage)					2.50%				2.00%				2.00%
Discount rate used in fair value calculations (percentage)					10.00%				10.00%				10.00%
Purchase accounting adjustment to reflect final determination of fair value							2,600,000							3,600,000
Number of radio stations	9,000											10,000
Acquisition purchase price paid in cash									45,000,000							40,000,000
Repayments of outstanding debt	106,125,000	88,931,000							215,000,000
Add: Cash received									235,000,000				235,000,000
Amount of purchase price placed in escrow												22,500,000
Revenues attributable to acquiree included in condensed consolidated statement of operations										56,500,000	190,500,000
Number of radio stations sold													53
Number of markets	90														12
Number of radio stations exchanged													15
Number of markets for radio stations exchanged															2
Total purchase price if certain future conditions are met				200,000													10,000,000
Estimated fair value of contingent consideration																	$ 31,000	$ 100,000	$ 100,000
Future market revenue growth rates for residual year																2.00%
Weighted average cost of capital																10.00%