Accounts Receivable - Net and Revenue Recognition (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended		12 Months Ended
	Apr. 01, 2018	Apr. 02, 2017	Apr. 01, 2018	Apr. 02, 2017	Oct. 01, 2017
Accounts Receivable - Net and Revenue Recognition
Period for billing and collecting unbilled receivables			12 months
Period for earning majority of billings in excess of costs			12 months
Unbilled accounts receivable related to claims and requests for equitable adjustment on contracts	$ 65.0		$ 65.0		$ 59.0
Gains (losses) from claim settlement			0.0
Billed accounts receivable related to U.S. federal government contracts	89.3		89.3		45.4
U.S. federal government unbilled receivables	104.5		$ 104.5		$ 109.7
Threshold percentage for disclosure of accounts receivable from a single client			10.00%		10.00%
Net unfavorable operating income adjustments				$ 8.0
Liabilities for anticipated losses	4.4		$ 4.4		$ 8.1
Estimated cost to complete the related contracts	4.6		4.6
CIG
Accounts Receivable - Net and Revenue Recognition
Net unfavorable operating income adjustments	$ 0.7		$ 1.4	2.3
RCM
Accounts Receivable - Net and Revenue Recognition
Gains (losses) from claim settlement				(3.2)
Reduction in the revenue related to the evaluation of the claims				4.5
Net unfavorable operating income adjustments		$ 4.0		$ 5.7