Fair Value Measurements - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended		12 Months Ended
	Sep. 30, 2018	Sep. 30, 2018	Oct. 01, 2017	Apr. 01, 2018	Apr. 02, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of deferred compensation plan assets	$ 18,700	$ 18,700		$ 16,900
Fair value of convertible notes	561,700	561,700		422,000
Payments to acquire assets		0	$ 12,956
Term B Loan
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of debt	198,500	198,500		199,600
Synkera Technologies, Inc.
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total purchase price					$ 2,800
Cash paid at closing					1,500
Contingent consideration liability					1,300
Contingent cash consideration (up to)					$ 1,500
Payments for achievement of certain milestones	700
Synkera Technologies, Inc. | Measured on a Recurring Basis | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent consideration liability	600	600		1,300
SpectraBeam, LLC
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Payments for achievement of certain milestones	2,100
SpectraBeam, LLC | Measured on a Recurring Basis | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent consideration liability	$ 2,000	$ 2,000		4,100
Developed technology | SpectraBeam, LLC
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent consideration liability				4,100
Total purchase consideration				17,000
Payments to acquire assets				$ 12,900