Quarterly report pursuant to Section 13 or 15(d)

Organization and Basis of Presentation - Narrative (Details)

v3.20.1
Organization and Basis of Presentation - Narrative (Details)
$ / shares in Units, $ in Thousands
3 Months Ended 6 Months Ended
Mar. 31, 2020
USD ($)
$ / shares
Mar. 31, 2020
USD ($)
segment
Oct. 01, 2019
USD ($)
Sep. 30, 2019
USD ($)
New Accounting Pronouncements or Change in Accounting Principle [Line Items]        
Goodwill $ 585,772 $ 585,772   $ 584,469
Billed, billable and unbilled accounts receivable 650,100 $ 650,100    
Number of operating segments | segment   3    
Bad debt expense 7,800      
Reduction of revenue (24,000)      
Reduction of net income $ (18,000)      
Reduction of diluted earnings per share | $ / shares $ (0.28)      
Total lease liabilities $ 187,995 $ 187,995    
Accounting Standards Update 2016-02        
New Accounting Pronouncements or Change in Accounting Principle [Line Items]        
Total lease liabilities     $ 214,500