Derivative Instruments and Hedging Activities (Net Gains (Losses) Recognized In Income For Derivative Contracts) (Details) - USD ($) $ in Thousands	12 Months Ended
Sep. 29, 2018	Sep. 30, 2017	Oct. 01, 2016
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Net gain (loss) recognized in other (expense) income, net	$ 316	$ (876)	$ (950)

The amount of net gains or losses on a cash flow hedge reclassified in the period to other (expense) income from accumulated other comprehensive income.

No definition available.

Name:	mtsc_CashFlowHedgeGainLossReclassifiedNetLossGainRecognizedInOtherExpenseIncomeNet
Namespace Prefix:	mtsc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration