CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares	Jun. 29, 2019	Dec. 29, 2018	Jun. 30, 2018
Stockholders’ equity:
Preferred stock, par value (dollars per share)	$ 1.00	$ 1.00	$ 1.00
Preferred stock, shares authorized (in shares)	40,000	40,000	40,000
Preferred stock, shares issued (in shares)	0	0	0
Common stock, par value (dollars per share)	$ 0.008	$ 0.008	$ 0.008
Common stock, shares authorized (in shares)	400,000,000	400,000,000	400,000,000
Common stock, shares issued (in shares)	173,238,000	171,887,000	170,728,000
Common stock, shares outstanding (in shares)	119,723,000	121,828,000	121,811,000
Treasury stock, shares (in shares)	53,515,000	50,059,000	48,917,000