Annual report pursuant to Section 13 and 15(d)

CERTAIN RELATIONSHIPS AND RELATED-PARTY TRANSACTIONS Certain Relationships and Related-Party Transactions (Details)

v3.8.0.1
CERTAIN RELATIONSHIPS AND RELATED-PARTY TRANSACTIONS Certain Relationships and Related-Party Transactions (Details)
$ in Thousands
12 Months Ended
Dec. 31, 2017
USD ($)
director
Dec. 31, 2016
USD ($)
Dec. 31, 2015
USD ($)
Related Party Transaction [Line Items]      
Related-party revenue $ 135,996 $ 123,521 $ 109,720
Related-party expenses 14,176 8,996 8,668
Related-party acquisition related   2,145  
Related-party payable $ 23,100 20,900  
Liberty Media [Member]      
Related Party Transaction [Line Items]      
Number of directors nominated by related party | director 2    
Equity Method Investee [Member]      
Related Party Transaction [Line Items]      
Related-party revenue $ 2,800 2,000 2,000
Related-party expenses $ 1,800 $ 3,200 $ 1,500