Annual report pursuant to Section 13 and 15(d)

ACQUISITIONS - Narrative (Details)

v3.10.0.1
ACQUISITIONS - Narrative (Details)
$ in Thousands, € in Millions
9 Months Ended 12 Months Ended
Feb. 01, 2018
USD ($)
Nov. 28, 2017
USD ($)
Mar. 01, 2017
USD ($)
Mar. 01, 2017
EUR (€)
Feb. 28, 2017
USD ($)
Jan. 13, 2017
USD ($)
Jan. 13, 2017
EUR (€)
Jan. 03, 2017
USD ($)
Jan. 03, 2017
EUR (€)
Nov. 30, 2016
USD ($)
Nov. 30, 2016
EUR (€)
Feb. 01, 2016
USD ($)
Jun. 30, 2018
USD ($)
Sep. 30, 2018
USD ($)
Sep. 30, 2017
USD ($)
Sep. 30, 2016
USD ($)
Business Acquisition [Line Items]                                
Cash payment to acquire business                           $ 121,065 $ 98,235 $ 6,937
Goodwill                           $ 948,894 $ 897,794 $ 851,489
Star Granite Bronze International, Inc                                
Business Acquisition [Line Items]                                
Total purchase price of Star Granite and Bronze International, Inc. $ 34,713                              
Cash payment to acquire business 29,713                              
Shares issued in business acquisition 5,000                              
Annual sales of business before acquisition $ 31,000                              
Compass Engineering Group, Inc                                
Business Acquisition [Line Items]                                
Cash payment to acquire business   $ 51,887                            
Annual sales of business before acquisition   $ 24,000                            
Series of Individually Immaterial Business Acquisitions                                
Business Acquisition [Line Items]                                
Cash payment to acquire business                         $ 39,465      
GJ Creative Limited                                
Business Acquisition [Line Items]                                
Purchase price of acquisition     $ 37,596 € 30.5                        
Annual sales of business before acquisition     $ 30,000                          
RAF Technology, Inc.                                
Business Acquisition [Line Items]                                
Purchase price of acquisition         $ 8,717                      
VCG (Holdings) Limited                                
Business Acquisition [Line Items]                                
Purchase price of acquisition           $ 10,695 € 8.8                  
Ungricht                                
Business Acquisition [Line Items]                                
Purchase price of acquisition               $ 25,185 € 24.0              
Annual sales of business before acquisition               $ 35                
Guidance Automation Limited                                
Business Acquisition [Line Items]                                
Purchase price of acquisition                   $ 9,974 € 8.0          
Digital Design, Inc.                                
Business Acquisition [Line Items]                                
Purchase price of acquisition                       $ 8,773