Quarterly report pursuant to Section 13 or 15(d)

Subsequent Events - Additional Information (Detail)

v3.10.0.1
Subsequent Events - Additional Information (Detail) - KCRO-AM and KOTK-AM [Member] - USD ($)
$ in Millions
Oct. 31, 2018
Jun. 30, 2018
Subsequent Event [Line Items]    
Business gross estimated gain loss on sale assets   $ 1.6
Subsequent Event [Member]    
Subsequent Event [Line Items]    
Proceeds from sale of other assets $ 1.4