Accumulated Other Comprehensive Income (Loss) - Reclassification Out of AOCI By Component (Details) - USD ($)	3 Months Ended
	Jul. 01, 2018	Jul. 02, 2017
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance, beginning	$ 645,372,000
Other comprehensive income (loss) before reclassifications	(2,679,000)
Net current-period other comprehensive income (loss)	(2,679,000)
Balance, ending	630,563,000
Interest income and other, net	1,671,000	$ 2,982,000
Accumulated other comprehensive income (loss)
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance, beginning	(4,763,000)
Balance, ending	(7,442,000)
Cumulative translation adjustments
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance, beginning	(2,151,000)
Other comprehensive income (loss) before reclassifications	(2,708,000)
Net current-period other comprehensive income (loss)	(2,708,000)
Balance, ending	(4,859,000)
Unrealized gain (loss) on available-for-sale investments
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance, beginning	(2,677,000)
Other comprehensive income (loss) before reclassifications	29,000
Net current-period other comprehensive income (loss)	29,000
Balance, ending	(2,648,000)
Unrealized gain (loss) on available-for-sale investments | Reclassification out of accumulated other comprehensive income
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Interest income and other, net	0
Pension adjustments
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance, beginning	65,000
Other comprehensive income (loss) before reclassifications	0
Net current-period other comprehensive income (loss)	0
Balance, ending	$ 65,000