v3.8.0.1
Commitments and contingencies - Leases (Details) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Capital and operating leases and notes payable      
Rent expense for leases $ 32,637 $ 27,140 $ 25,099
Interest expense associated with capital financing arrangements 302 158 58
Rent expense for leases of office facilities $ 2,936 $ 2,993 $ 2,995
Term of capital lease 3 years    
Capital Leases and Notes Payable      
2018 $ 6,035    
2019 4,701    
2020 2,179    
2021 0    
2022 0    
Thereafter 0    
Minimum lease payments 12,915    
Less: Amounts representing interest ranging from 2.0% to 7.7% (397)    
Minimum lease payments 12,518    
Current portion 5,771    
Non current portion 6,747    
Operating Leases and Venue Guarantees      
2018 12,850    
2019 10,758    
2020 10,077    
2021 7,650    
2022 8,494    
Thereafter 19,217    
Minimum lease payments $ 69,046    
Minimum      
Capital Leases and Notes Payable      
Interest rate (as a percent) 2.00%    
Maximum      
Capital Leases and Notes Payable      
Interest rate (as a percent) 7.70%    
Operating Leases and Venue Guarantees      
Initial term of operating leases 20 years    
Notes payable      
Capital and operating leases and notes payable      
Term of the debt 3 years