Investments Investments (Details Textual 2) - USD ($) $ in Thousands	12 Months Ended
	Dec. 28, 2019	Dec. 29, 2018
Other Investment Not Readily Marketable [Line Items]
Non-marketable investments	$ 138,212	$ 118,734
Other equity investments not readily marketable [Member]
Other Investment Not Readily Marketable [Line Items]
Non-marketable investments	1,900	2,800
Net gains on equity securities without readily determinable fair value	2,100	3,300
Unrealized gains (losses) for the period that relate to equity securities without readily determinable fair values still held at the reporting date.	$ 900	$ 100