Basis of Presentation and Preparation - Contingent Consideration and Concentration of Credit Risk (Details)	12 Months Ended
	Oct. 01, 2017 Institution
Concentration of Credit Risk
Financial institutions, in any such number of which investment exposure is limited	1
Accounts receivable due from various agencies of the U.S. federal government (as a percent)	23.00%
U.S. government
Concentration of Credit Risk
Revenue from customers (as a percent)	45.00%
U.S. commercial
Concentration of Credit Risk
Revenue from customers (as a percent)	28.00%
International
Concentration of Credit Risk
Revenue from customers (as a percent)	27.00%
Minimum
Contingent Consideration
Period for contingent earn-out payments	2 years
Maximum
Contingent Consideration
Period for contingent earn-out payments	3 years