Revenue Recognition - Trade and Barter Transactions Expenses (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Revenue Recognition [Line Items]
Total net revenue	$ 236,239	$ 253,898
Broadcast [Member] | Advertising Barter Transactions [Member]
Revenue Recognition [Line Items]
Total net revenue	2,810	5,625
Cost	2,952	5,055
Publishing [Member]
Revenue Recognition [Line Items]
Total net revenue	18,519	21,394
Publishing [Member] | Advertising Barter Transactions [Member]
Revenue Recognition [Line Items]
Total net revenue	38	63
Cost	$ 1	$ 20