XML 90 R66.htm IDEA: XBRL DOCUMENT v3.24.0.1
Contract Balances - Narrative (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2023
Dec. 31, 2022
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]    
Amounts due to third parties for reimbursable expenses $ 333,000 $ 406,300
Change in unbilled receivables (5,719)  
Change in unearned revenue (payments on account) (147,058)  
Increase in advance payments netted against unbilled contracts receivable (152,777)  
Bad debt expense 24,600 17,800
Revenue, remaining performance obligation, amount $ 14,800,000 $ 13,700,000
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-01-01    
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]    
Revenue, remaining performance obligation (in percent)   52.00%
Revenue, remaining performance obligation, expected timing of satisfaction, period 12 months  
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-01-01    
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]    
Revenue, remaining performance obligation (in percent) 52.00%  
Revenue, remaining performance obligation, expected timing of satisfaction, period   12 months