Marketable Securities - Available for Sale Securities (Details) - USD ($) $ in Thousands	Dec. 26, 2021	Dec. 27, 2020
Debt Securities, Available-for-sale [Line Items]
Net unrealized gain (loss) in AOCI	$ (383,202)	$ (410,181)
Short-term AFS securities
Amortized cost, short-term AFS securities	340,252	308,490
Gross unrealized gains, short-term AFS securities	937	604
Gross unrealized losses, short-term AFS securities	(114)	(14)
Fair value, short-term AFS securities	341,075	309,080
Long-term AFS securities
Amortized cost, long-term AFS securities	415,951	283,143
Gross unrealized gains, long-term AFS securities	149	3,716
Gross unrealized losses, long-term AFS securities	(2,720)	(28)
Fair value, long-term AFS securities	413,380	286,831
U.S. Treasury securities
Short-term AFS securities
Amortized cost, short-term AFS securities	148,899	79,467
Gross unrealized gains, short-term AFS securities	692	39
Gross unrealized losses, short-term AFS securities	(43)	(3)
Fair value, short-term AFS securities	149,548	79,503
Long-term AFS securities
Amortized cost, long-term AFS securities	119,695	95,511
Gross unrealized gains, long-term AFS securities	0	2,054
Gross unrealized losses, long-term AFS securities	(549)	0
Fair value, long-term AFS securities	119,146	97,565
Corporate debt securities
Short-term AFS securities
Amortized cost, short-term AFS securities	107,158	129,805
Gross unrealized gains, short-term AFS securities	245	504
Gross unrealized losses, short-term AFS securities	(69)	(8)
Fair value, short-term AFS securities	107,334	130,301
Long-term AFS securities
Amortized cost, long-term AFS securities	242,764	134,296
Gross unrealized gains, long-term AFS securities	149	1,643
Gross unrealized losses, long-term AFS securities	(1,858)	(5)
Fair value, long-term AFS securities	241,055	135,934
Certificates of deposit
Short-term AFS securities
Amortized cost, short-term AFS securities	55,551	36,525
Gross unrealized gains, short-term AFS securities	0	0
Gross unrealized losses, short-term AFS securities	0	0
Fair value, short-term AFS securities	55,551	36,525
Commercial paper
Short-term AFS securities
Amortized cost, short-term AFS securities	21,145	37,580
Gross unrealized gains, short-term AFS securities	0	0
Gross unrealized losses, short-term AFS securities	0	0
Fair value, short-term AFS securities	21,145	37,580
Municipal securities
Short-term AFS securities
Amortized cost, short-term AFS securities	3,999
Gross unrealized gains, short-term AFS securities	0
Gross unrealized losses, short-term AFS securities	(2)
Fair value, short-term AFS securities	3,997
Long-term AFS securities
Amortized cost, long-term AFS securities	13,994	4,994
Gross unrealized gains, long-term AFS securities	0	0
Gross unrealized losses, long-term AFS securities	(61)	(10)
Fair value, long-term AFS securities	13,933	4,984
U.S. governmental agency securities
Short-term AFS securities
Amortized cost, short-term AFS securities	3,500	25,113
Gross unrealized gains, short-term AFS securities	0	61
Gross unrealized losses, short-term AFS securities		(3)
Fair value, short-term AFS securities	3,500	25,171
Long-term AFS securities
Amortized cost, long-term AFS securities	39,498	48,342
Gross unrealized gains, long-term AFS securities	0	19
Gross unrealized losses, long-term AFS securities	(252)	(13)
Fair value, long-term AFS securities	39,246	48,348
Debt Securities
Debt Securities, Available-for-sale [Line Items]
Net unrealized gain (loss) in AOCI	$ 1,700	$ 4,300