Marketable Securities (Details) - USD ($)	3 Months Ended	6 Months Ended
	Dec. 29, 2018	Dec. 28, 2019	Jun. 29, 2019
Marketable Securities [Line Items]
Amortized Cost Basis		$ 118,640,000	$ 116,440,000
Gross Unrealized Gains		4,274,000	3,579,000
Gross Unrealized Losses		(3,000)	0
Fair Value		122,911,000	120,019,000
Realized gain (loss) on marketable securities	$ 0	$ 0
Minimum
Marketable Securities [Line Items]
Debt securities maturities		1 year
Maximum
Marketable Securities [Line Items]
Debt securities maturities		11 years
Short-Term Marketable Securities
Marketable Securities [Line Items]
Fair Value		$ 15,047,000	12,006,000
Long-Term Marketable Securities
Marketable Securities [Line Items]
Fair Value		107,864,000	108,013,000
Corporate bonds
Marketable Securities [Line Items]
Amortized Cost Basis		89,872,000	87,540,000
Gross Unrealized Gains		2,122,000	1,734,000
Gross Unrealized Losses		(3,000)	0
Fair Value		91,991,000	89,274,000
Corporate bonds | Short-Term Marketable Securities
Marketable Securities [Line Items]
Fair Value		15,047,000	12,006,000
Corporate bonds | Long-Term Marketable Securities
Marketable Securities [Line Items]
Fair Value		76,944,000	77,268,000
Government bonds
Marketable Securities [Line Items]
Amortized Cost Basis		28,768,000	28,900,000
Gross Unrealized Gains		2,152,000	1,845,000
Gross Unrealized Losses		0	0
Fair Value		30,920,000	30,745,000
Government bonds | Short-Term Marketable Securities
Marketable Securities [Line Items]
Fair Value		0	0
Government bonds | Long-Term Marketable Securities
Marketable Securities [Line Items]
Fair Value		$ 30,920,000	$ 30,745,000