Reportable Segments - Financial Information (Details) $ in Thousands	3 Months Ended	6 Months Ended
Mar. 29, 2020 USD ($)	Mar. 31, 2019 USD ($)	Mar. 29, 2020 USD ($) segment	Mar. 31, 2019 USD ($)	Sep. 29, 2019 USD ($)
Financial information regarding reportable segments
Number of reportable segments \| segment			2
Revenue	$ 734,133	$ 722,621	$ 1,531,756	$ 1,440,052
Income from operations	47,530	47,545	110,832	103,256
Total Assets	2,343,150		2,343,150		$ 2,147,408
Operating segment \| GSG
Financial information regarding reportable segments
Revenue	436,903	417,526	894,307	829,497
Income from operations	35,347	44,803	77,395	82,217
Total Assets	546,090		546,090		587,040
Operating segment \| CIG
Financial information regarding reportable segments
Revenue	308,412	322,458	659,576	640,252
Income from operations	21,676	20,869	53,309	47,968
Total Assets	362,446		362,446		450,276
Operating segment \| RCM
Financial information regarding reportable segments
Revenue	5	(4,645)	150	(3,192)
Income from operations	(1)	(5,938)	1	(5,934)
Total Assets	14,285		14,285		15,608
Elimination of inter-segment revenue
Financial information regarding reportable segments
Revenue	(11,187)	(12,718)	(22,277)	(26,505)
Corporate
Financial information regarding reportable segments
Income from operations	(9,492)	$ (12,189)	(19,873)	$ (20,995)
Total Assets	$ 1,420,329		$ 1,420,329		$ 1,094,484

Sum of the carrying amounts as of the balance sheet date of all assets that are recognized. Assets are probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

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