Annual report pursuant to Section 13 and 15(d)

Business segments - Schedule of Segment Reporting Results By Segment (Details)

v3.5.0.2
Business segments - Schedule of Segment Reporting Results By Segment (Details)
$ in Thousands
3 Months Ended 12 Months Ended
Sep. 30, 2016
USD ($)
Jun. 30, 2016
USD ($)
Mar. 31, 2016
USD ($)
Dec. 31, 2015
USD ($)
Sep. 30, 2015
USD ($)
Jun. 30, 2015
USD ($)
Mar. 31, 2015
USD ($)
Dec. 31, 2014
USD ($)
Sep. 30, 2016
USD ($)
segment
Sep. 30, 2015
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Sep. 30, 2014
USD ($)
Segment Reporting [Abstract]                      
Number of business segments | segment                 3    
Financial information for each of the Company's business segments                      
Revenue $ 623,091 $ 617,094 $ 606,453 $ 556,722 $ 578,683 $ 572,301 $ 481,794 $ 467,043 $ 2,403,360 $ 2,099,821 $ 1,700,912
Gross profit 152,930 151,379 147,667 110,215 125,307 143,798 124,345 119,267 562,191 512,717 452,123
Selling, general and administrative expense                 268,259 238,792 220,925
Operating income 81,308 84,609 77,900 42,786 61,527 71,067 62,007 65,231 286,603 259,832 225,308
Amortization of intangible assets                 (13,377) (9,348) (5,890)
Acquisition-related expenses                 (832) (4,745) 0
Gain on sale of a business                 $ 6,880 $ 0 $ 0
Percentage of total revenue                 11.90% 12.40% 13.20%
Depreciation and amortization                 $ 58,404 $ 46,849 $ 42,778
Other/Corporate                      
Financial information for each of the Company's business segments                      
Selling, general and administrative expense (622) 2,127 0 650 (102) 8 95 5 2,155 6 614
Other                 (2,155) (6) (614)
Segment Reconciling Items                      
Financial information for each of the Company's business segments                      
Amortization of intangible assets (3,449) (3,517) (3,262) (3,149) (3,166) (3,275) (1,432) (1,475) (13,377) (9,348) (5,890)
Acquisition-related expenses (257) 0 (529) (46) $ 172 $ 2,459 $ 1,514 $ 600 (832) (4,745) 0
Gain on sale of a business $ 427 $ 6,453 $ 0 $ 0         6,880 0 0
Health Services                      
Financial information for each of the Company's business segments                      
Revenue                 1,298,304 1,109,238 906,650
Gross profit                 292,181 254,108 213,728
Selling, general and administrative expense                 107,155 99,815 98,172
Operating income                 $ 185,026 $ 154,293 $ 115,556
Percentage of total revenue                 14.30% 13.90% 12.70%
Depreciation and amortization                 $ 31,916 $ 27,694 $ 23,994
U.S. Federal Services                      
Financial information for each of the Company's business segments                      
Revenue                 591,728 502,484 341,840
Gross profit                 138,168 118,646 110,793
Selling, general and administrative expense                 74,792 59,252 47,695
Operating income                 $ 63,376 $ 59,394 $ 63,098
Percentage of total revenue                 10.70% 11.80% 18.50%
Depreciation and amortization                 $ 9,953 $ 10,363 $ 9,557
Human Services                      
Financial information for each of the Company's business segments                      
Revenue                 513,328 488,099 452,422
Gross profit                 131,842 139,963 127,602
Selling, general and administrative expense                 84,157 79,719 74,444
Operating income                 $ 47,685 $ 60,244 $ 53,158
Percentage of total revenue                 9.30% 12.30% 11.70%
Depreciation and amortization                 $ 16,535 $ 8,792 $ 9,227