Quarterly report pursuant to Section 13 or 15(d)

Acquisitions - 2017 Acquisitions (Details)

v3.8.0.1
Acquisitions - 2017 Acquisitions (Details) - USD ($)
$ in Thousands
1 Months Ended 3 Months Ended
Oct. 31, 2017
Sep. 30, 2017
Aug. 31, 2017
Jun. 30, 2017
Feb. 28, 2017
Jan. 31, 2017
Mar. 31, 2018
Mar. 31, 2017
Dec. 31, 2017
Dec. 31, 2016
Business Acquisition [Line Items]                    
Goodwill             $ 751,017   $ 751,052  
Gain (loss) recognized due to change in fair value of cash consideration             (402) $ (121)    
Payments of acquisition-related consideration             776 6,461    
LRO                    
Business Acquisition [Line Items]                    
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net             299,923      
Cash, net of cash acquired         $ 298,000          
Deferred cash payment amount related to acquisition         1,600          
Reimbursable legal fees     50.00%              
Total purchase price         299,900          
Deferred cash obligations, net         1,500          
Liabilities assumed         400          
Goodwill         203,200   203,171      
Gross contractual amount of acquired receivables         4,700          
Estimated uncollectable amount of acquired receivables         200          
Acquisition costs         $ 13,800          
PEX                    
Business Acquisition [Line Items]                    
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net             6,031      
Cash, net of cash acquired $ 5,100                  
Deferred cash payment amount related to acquisition 1,000                  
Total purchase price 6,000                  
Cash acquired 100                  
Deferred cash obligations, net $ 900                  
Length of time for acquisition contingent cash payment to be made 24 months                  
Goodwill $ 3,200           3,242      
Acquisition costs $ 400                  
On-Site                    
Business Acquisition [Line Items]                    
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net             253,430      
Cash, net of cash acquired   $ 225,300                
Deferred cash payment amount related to acquisition   $ 29,600                
Length of time for acquisition deferred cash payment to be made   12 months                
Total purchase price   $ 253,400                
Cash acquired   1,700                
Deferred cash obligations, net   $ 28,100                
Length of time for acquisition contingent cash payment to be made   36 months                
Goodwill   $ 184,500         184,534      
Gross contractual amount of acquired receivables   5,600                
Estimated uncollectable amount of acquired receivables   900                
Acquisition costs   $ 1,800                
AUM                    
Business Acquisition [Line Items]                    
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net             69,412      
Cash, net of cash acquired       $ 64,800            
Deferred cash payment amount related to acquisition       $ 5,100            
Length of time for acquisition deferred cash payment to be made       4 years            
Cash acquired       $ 100            
Deferred cash obligations, net       4,600            
Goodwill       45,900     45,907      
Gross contractual amount of acquired receivables       2,700            
Estimated uncollectable amount of acquired receivables       300            
Acquisition costs       $ 300            
Axiometrics                    
Business Acquisition [Line Items]                    
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net             73,757      
Cash, net of cash acquired           $ 66,100        
Deferred cash payment amount related to acquisition           $ 7,500        
Length of time for acquisition deferred cash payment to be made           2 years        
Deferred cash obligations, net           $ 6,900        
Length of time for acquisition contingent cash payment to be made           12 months        
Goodwill           $ 54,200 54,190      
Acquisition costs           300        
Contingent cash obligation/payment           5,000        
Contingent consideration liability           $ 800        
2017 Acquisitions                    
Business Acquisition [Line Items]                    
Deferred cash obligation             44,000   44,800  
Deferred cash obligation discount             (1,200)   (2,300)  
Gain (loss) recognized due to change in fair value of cash consideration             100      
Payments of acquisition-related consideration             200      
Developed product technologies | LRO                    
Business Acquisition [Line Items]                    
Amortized useful life of acquired intangible assets         7 years          
Developed product technologies | PEX                    
Business Acquisition [Line Items]                    
Amortized useful life of acquired intangible assets 7 years                  
Developed product technologies | On-Site                    
Business Acquisition [Line Items]                    
Amortized useful life of acquired intangible assets   5 years                
Developed product technologies | AUM                    
Business Acquisition [Line Items]                    
Amortized useful life of acquired intangible assets       3 years            
Developed product technologies | Axiometrics                    
Business Acquisition [Line Items]                    
Amortized useful life of acquired intangible assets           5 years        
Client relationships | LRO                    
Business Acquisition [Line Items]                    
Amortized useful life of acquired intangible assets         10 years          
Client relationships | PEX                    
Business Acquisition [Line Items]                    
Amortized useful life of acquired intangible assets 9 years                  
Client relationships | On-Site                    
Business Acquisition [Line Items]                    
Amortized useful life of acquired intangible assets   10 years                
Client relationships | AUM                    
Business Acquisition [Line Items]                    
Amortized useful life of acquired intangible assets       10 years            
Client relationships | Axiometrics                    
Business Acquisition [Line Items]                    
Amortized useful life of acquired intangible assets           10 years        
Trade names | LRO                    
Business Acquisition [Line Items]                    
Amortized useful life of acquired intangible assets         2 years          
Trade names | PEX                    
Business Acquisition [Line Items]                    
Amortized useful life of acquired intangible assets 6 years                  
Trade names | On-Site                    
Business Acquisition [Line Items]                    
Amortized useful life of acquired intangible assets   2 years                
Trade names | AUM                    
Business Acquisition [Line Items]                    
Amortized useful life of acquired intangible assets       2 years            
Trade names | Axiometrics                    
Business Acquisition [Line Items]                    
Amortized useful life of acquired intangible assets           3 years        
Non-compete agreements | AUM                    
Business Acquisition [Line Items]                    
Amortized useful life of acquired intangible assets       5 years            
Hart-Scott-Rodino Antitrust Improvements Act Review Process | LRO                    
Business Acquisition [Line Items]                    
Acquisition costs         $ 10,700          
Recurring                    
Business Acquisition [Line Items]                    
Liabilities measured at fair value             104   414  
Contingent Consideration | Recurring | Axiometrics                    
Business Acquisition [Line Items]                    
Liabilities measured at fair value             104   167  
Level 3 | Recurring                    
Business Acquisition [Line Items]                    
Liabilities measured at fair value             104   414  
Level 3 | Contingent Consideration                    
Business Acquisition [Line Items]                    
Liabilities measured at fair value             104 $ 1,516 414 $ 541
Level 3 | Contingent Consideration | Recurring | Axiometrics                    
Business Acquisition [Line Items]                    
Liabilities measured at fair value             104   167  
Level 3 | Contingent Consideration | Recurring | 2017 Acquisitions                    
Business Acquisition [Line Items]                    
Liabilities measured at fair value             $ 100   $ 200