Borrowings (Details) € in Millions	3 Months Ended				6 Months Ended
	Dec. 30, 2017 EUR (€)	Dec. 30, 2017 USD ($)	Dec. 31, 2016 EUR (€)	Dec. 31, 2016 USD ($)	Apr. 01, 2017	Dec. 30, 2017 USD ($)	Sep. 30, 2017 USD ($)	Nov. 07, 2016 EUR (€)	Nov. 07, 2016 USD ($)	Aug. 01, 2016 EUR (€)
Debt [Line Items]
Repayments of Debt				$ 50,000,000
Aggregate principal of two term loans									$ (15,300,000)
Aggregate amount of several lines of credit									$ 18,100,000
Debt issuance cost related to repricing				500,000
Amortization of debt issuance cost		$ 3,815,000		600,000
Additional sources of cash available						$ 29,200,000
Debt Instrument, Unused Borrowing Capacity, Amount						21,400,000
Short-term borrowings						6,928,000	$ 5,078,000
Total contractual obligation due amount						529,591,000
Euro Member Countries, Euro
Debt [Line Items]
Domesticlineofcreditdrawn | €								€ 10.0
Credit Agreement November 7 2016 [Domain] | net leverage ratio [Domain]
Debt [Line Items]
Senior Secured Net leverage ratio to increase revolving commitment or borrow incremental term loan								2.75	2.75
Senior secured net leverage ratio to maintain compliance on the loan each quarter end								3.50	3.50
Rofin-Sinar
Debt [Line Items]
Lines of credit									$ 30,000,000
Swing line, maximum borrowing capacity									$ 10,000,000
Euro term loan
Debt [Line Items]
Amortization period of the debt issuance cost					7 years
Debt Issuance Costs for revolving credit facility				28,500,000
Euro term loan | Euro Member Countries, Euro
Debt [Line Items]
forward contract purchased for the term loan | €	€ 436.6							€ 670.0		€ 670.0
Voluntary payment of principle | €	75.0		€ 150.0
Euro currency rate range initially								0.035	0.035
Euro currency rate range after 1st year								0.03	0.03
Additional Euro currency rate								0.01	0.01
Quarter principal payment requirement for Euro term loan								0.0025	0.0025
Euro term loan | Minimum | Euro Member Countries, Euro
Debt [Line Items]
Applicable margin for Eurocurrency rate loan								0.0375	0.0375
Euro term loan | Maximum | Euro Member Countries, Euro
Debt [Line Items]
Euro currency rate range after 1st year								0.035	0.035
Applicable margin for Eurocurrency rate loan								0.0425	0.0425
Revolving line of credit [Domain]
Debt [Line Items]
Revolving facility to finance acquisition of Rofin	€ 10.0								$ 100,000,000
Revolving facility borrowing capapcity potential increase									150,000,000
cash excess that requires the loan repayment									$ 10,000,000
Debt Issuance Costs for revolving credit facility				$ 2,300,000
debt issuance cost amortization period			5 years	5 years
Base rate initially								0.025	0.025
Additional base rate								0.005	0.005
Interest rate of term loan								0.013	0.013
Interest rate of state of Connecticut term loan								0.01	0.01
Revolving line of credit [Domain] | Minimum
Debt [Line Items]
Base rate range after 1st year								0.02	0.02
Applicable margin for base rate revolving loan								0.0275	0.0275
Commitment fee accrues range on unused portion of revolving loan								0.0375	0.0375
Revolving line of credit [Domain] | Maximum
Debt [Line Items]
Base rate range after 1st year								0.025	0.025
Applicable margin for base rate revolving loan								0.0325	0.0325
Commitment fee accrues range on unused portion of revolving loan								0.005	0.005
Line of Credit, Foreign
Debt [Line Items]
Amounts drawn upon line of credit						6,000,000
Foreign Line of Credit [Member]
Debt [Line Items]
Short-term borrowings						$ 1,800,000