XML 66 R53.htm IDEA: XBRL DOCUMENT v3.21.2
Leases (Details)
£ in Thousands, ft² in Thousands, $ in Thousands
1 Months Ended 3 Months Ended 9 Months Ended
Oct. 31, 2021
USD ($)
ft²
Sep. 30, 2021
USD ($)
ft²
Sep. 30, 2021
GBP (£)
Sep. 30, 2020
USD ($)
Sep. 30, 2021
USD ($)
ft²
Sep. 30, 2020
USD ($)
Dec. 31, 2020
USD ($)
Lessee, Lease, Description [Line Items]              
Operating Lease, Cost   $ 12,563   $ 12,248 $ 37,063 $ 36,272  
Variable Lease, Cost   1,502   1,841 5,120 4,696  
Operating Lease, Payments         31,714 22,469  
Operating Lease, Incentive Payments Received         8,924 10,267  
Lessee, Additional Payments for Operating Leases Not Yet Commenced   $ 199,237     $ 199,237    
Minimum [Member]              
Lessee, Lease, Description [Line Items]              
Lessee, Operating Lease, Lease Not yet Commenced, Term of Contract   1 year     1 year    
Maximum [Member]              
Lessee, Lease, Description [Line Items]              
Lessee, Operating Lease, Lease Not yet Commenced, Term of Contract   13 years     13 years    
Office Equipment [Member]              
Lessee, Lease, Description [Line Items]              
Operating Lease, Cost   $ 1,332   $ 1,170 $ 3,983 $ 3,497  
Building [Member] | UNITED KINGDOM              
Lessee, Lease, Description [Line Items]              
Net Rentable Area | ft²   14     14    
Building [Member] | United States [Member] | Subsequent Event [Member]              
Lessee, Lease, Description [Line Items]              
Net Rentable Area | ft² 30            
Building [Member] | Annual Expense | UNITED KINGDOM              
Lessee, Lease, Description [Line Items]              
Operating Lease, Cost | £     £ 1,081        
Building [Member] | Annual Expense | United States [Member] | Subsequent Event [Member]              
Lessee, Lease, Description [Line Items]              
Operating Lease, Cost $ 2,200            
Letter of Credit [Member]              
Lessee, Lease, Description [Line Items]              
Other Assets   $ 5,616     $ 5,616   $ 5,550