Annual report pursuant to Section 13 and 15(d)

Commitments and contingencies (Details)

v3.3.0.814
Commitments and contingencies (Details) - USD ($)
$ in Thousands
 3 Months Ended 12 Months Ended
Sep. 30, 2015
Jun. 30, 2015
Mar. 31, 2015
Dec. 31, 2014
Sep. 30, 2014
Jun. 30, 2014
Mar. 31, 2014
Dec. 31, 2013
Sep. 30, 2015
Sep. 30, 2014
Sep. 30, 2013
Apr. 30, 2012
Performance bonds                        
Performance bond commitments $ 27,300               $ 27,300      
Operating Lease expense                 67,100 $ 61,800 $ 49,000  
Operating sublease income                 500      
Minimum future lease commitments under leases                        
2016 70,892               70,892      
2017 56,876               56,876      
2018 40,892               40,892      
2019 29,693               29,693      
2020 18,505               18,505      
Thereafter 4,919               4,919      
Total minimum lease payments 221,777               221,777      
Deferred revenue recorded 52,954       $ 32,257       52,954 32,257    
Additional revenue recognized from significant contract 578,683 $ 572,301 $ 481,794 $ 467,043 435,406 $ 419,899 $ 439,015 $ 406,592 2,099,821 1,700,912 1,331,279  
Additional cost recognized for significant contract                 1,587,104 1,248,789 945,246  
Operating profit 61,527 $ 71,067 $ 62,007 $ 65,231 $ 51,808 $ 55,223 $ 64,980 $ 53,297 $ 259,832 $ 225,308 185,155  
Percentage of employees covered by collective bargaining agreements                 18.00%      
Sublease income 1,200               $ 1,200      
PSI | Loss contract                        
Minimum future lease commitments under leases                        
Deferred revenue recorded                       $ 15,100
Additional revenue recognized from significant contract                     16,000  
Additional cost recognized for significant contract                     5,100  
Operating profit                     $ 10,900  
Office space                        
Minimum future lease commitments under leases                        
2016 66,172               66,172      
2017 52,745               52,745      
2018 37,475               37,475      
2019 27,004               27,004      
2020 16,971               16,971      
Thereafter 4,919               4,919      
Total minimum lease payments 205,286               205,286      
Equipment                        
Minimum future lease commitments under leases                        
2016 4,720               4,720      
2017 4,131               4,131      
2018 3,417               3,417      
2019 2,689               2,689      
2020 1,534               1,534      
Total minimum lease payments $ 16,491               $ 16,491