Accumulated Other Comprehensive Income (Loss) - Components of Reclassification Out of Comprehensive Income (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Dec. 31, 2017	Jan. 01, 2017	Dec. 31, 2017	Jan. 01, 2017
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Interest income and other, net	$ 1,570	$ 407	$ 6,500	$ 3,679
Unrealized holding loss on available-for-sale investments | Reclassification out of accumulated other comprehensive income
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Interest income and other, net			$ 38