Earnings Per Share and Shareholders Equity (Details) - USD ($) shares in Thousands, $ in Millions	3 Months Ended		6 Months Ended
	Jul. 02, 2016	Jun. 27, 2015	Jul. 02, 2016	Jun. 27, 2015	Oct. 22, 2015
Numerator:
Net loss	$ (534.3)	$ (22.2)	$ (1,063.5)	$ (44.5)
Denominator:
Weighted average shares outstanding for basic EPS (in shares)	143,200	146,300	143,200	143,500
Dilutive effect of share-based awards (in shares)	0	0	0	0
Weighted average shares outstanding for diluted EPS (in shares)	143,200	146,300	143,200	143,500
Anti-dilutive share-based awards excluded from computation of diluted EPS (in shares)	0	0	0	0
Shares issued (in shares)	19	57	98	92
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Authorized repurchase amount (up to)	$ 0.0		$ 0.0
Remaining available for repurchase	$ 1,500.0		$ 1,500.0
Perrigo Co PLC
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Authorized repurchase amount (up to)					$ 2,000.0