Annual report pursuant to Section 13 and 15(d)

Percentage Within Range by Which Enterprise Value Exceeded Carrying Value of Each Clusters Including Goodwill (Detail)

v2.4.0.6
Percentage Within Range by Which Enterprise Value Exceeded Carrying Value of Each Clusters Including Goodwill (Detail) (Goodwill-Broadcast, USD $)
In Thousands, unless otherwise specified
 12 Months Ended
Dec. 31, 2012
Entity
Dec. 31, 2011
Entity
Dec. 31, 2010
Entity
Less than 10%
      
Carrying Amounts and Fair Values of Financial Instruments [Line Items]      
Number of market clusters 2 1 2
Carrying value $ 18,836 $ 9,877 $ 19,502
>10% To 20%
      
Carrying Amounts and Fair Values of Financial Instruments [Line Items]      
Number of market clusters 1 2  
Carrying value 1,423 17,487  
>20% To 50 %
      
Carrying Amounts and Fair Values of Financial Instruments [Line Items]      
Number of market clusters 1 3 2
Carrying value 10,506 68,506 66,871
> than 50%
      
Carrying Amounts and Fair Values of Financial Instruments [Line Items]      
Number of market clusters 5 2 3
Carrying value $ 132,645 $ 5,178 $ 7,295