Condensed Consolidated Balance Sheets (Parenthetical) $ in Millions	Sep. 27, 2019 USD ($) $ / shares shares	Sep. 27, 2019 € / shares	Dec. 28, 2018 USD ($) $ / shares shares	Dec. 28, 2018 € / shares
Allowance for doubtful accounts | $	$ 4.5		$ 5.0
Preferred shares, par value (in usd per share) | $ / shares	$ 0.20		$ 0.20
Preferred shares, shares authorized (in shares)	500,000,000		500,000,000
Preferred shares, shares issued (in shares)	0		0
Preferred shares, shares outstanding (in shares)	0		0
Ordinary shares, par value (in usd per share) | $ / shares	$ 0.20		$ 0.20
Ordinary shares, shares authorized (in shares)	500,000,000		500,000,000
Ordinary shares, shares issued (in shares)	93,427,563		92,705,747
Ordinary shares, shares outstanding (in shares)	84,078,103		83,323,877
Ordinary shares held in treasury at cost (in shares)	9,349,460		9,381,870
Ordinary A
Ordinary shares, par value (in usd per share) | € / shares		€ 1.00		€ 1.00
Ordinary shares, shares authorized (in shares)	40,000		40,000
Ordinary shares, shares issued (in shares)	0		0
Ordinary A shares, shares outstanding (in shares)	0		0