Commitments and Contingencies - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2015 USD ($) ft²	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)
Contingencies And Commitments [Line Items]
Lease commitment with media research and rating providers, aggregate amount	$ 26,900,000
Non-cancelable operating lease expiration term	2016-12
Total rent expense under operating leases	$ 10,900,000	$ 9,900,000	$ 9,800,000
Bonus paid to executives		$ 200,000	$ 200,000
Bonus accrued to executives	$ 200,000
Santa Monica
Contingencies And Commitments [Line Items]
Area under operating leases for corporate headquarters | ft²	16,000
Lease Expiration Year	2021
Los Angeles
Contingencies And Commitments [Line Items]
Area under operating leases for corporate headquarters | ft²	41,000
Lease Expiration Year	2026
Facilities and Broadcast Equipment
Contingencies And Commitments [Line Items]
Non-cancelable operating lease expiration term	2059-12
Minimum
Contingencies And Commitments [Line Items]
Lease commitment with media research and rating providers, annual commitment range	$ 6,600,000
Maximum
Contingencies And Commitments [Line Items]
Lease commitment with media research and rating providers, annual commitment range	$ 13,300,000