CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (DEFICIT) (Parenthetical) - shares	3 Months Ended
	Sep. 29, 2019	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2018	Jul. 01, 2018	Apr. 01, 2018
Treasury stock, acquired (in shares)	1,856	851	56,934	5,499	6,193	33,805
Common Class A
Issuance of shares under stock plans	6,260	2,320	168,610	43,860	34,830	94,184
Shares issued in conversion					15,000