Condensed Consolidating Financial Statements (Schedule of Condensed Consolidating Statements of Cash Flows) (Details) - USD ($) $ in Millions	9 Months Ended
	Jun. 26, 2015	Jun. 27, 2014
Cash Flows From Operating Activities:
Net cash provided by (used in) operating activities	$ 559.2	$ 168.1
Cash Flows From Investing Activities:
Capital expenditures	(92.5)	(80.1)
Intercompany loan investment	0.0	0.0
Investment in subsidiary	0.0	0.0
Acquisitions and intangibles, net of cash acquired	(1,176.3)	(1,303.2)
Restricted cash	(21.9)	4.1
Other	2.6	8.7
Net cash used in investing activities	(1,288.1)	(1,370.5)
Cash Flows From Financing Activities:
Issuance of external debt	1,720.0	1,296.8
Repayment of external debt and capital leases	(1,457.8)	(31.2)
Debt financing costs	(25.3)	(32.2)
Excess tax benefit from share-based compensation	30.4	5.2
Proceeds from exercise of share options	29.7	19.9
Repurchase of shares	(15.4)	(1.9)
Intercompany loan borrowings, net	0.0	0.0
Capital contribution	0.0	0.0
Other	28.1	0.0
Net cash provided by financing activities	253.5	1,256.6
Effect of currency rate changes on cash	(7.1)	(1.8)
Net increase (decrease) in cash and cash equivalents	(482.5)	52.4
Cash and cash equivalents at beginning of period	707.8	275.5
Cash and cash equivalents at end of period	225.3	327.9
Mallinckrodt plc
Cash Flows From Operating Activities:
Net cash provided by (used in) operating activities	164.2	9.9
Cash Flows From Investing Activities:
Capital expenditures	0.0	0.0
Intercompany loan investment	(178.6)	(26.3)
Investment in subsidiary	0.0	0.0
Acquisitions and intangibles, net of cash acquired	0.0	0.0
Restricted cash	0.0	0.0
Other	0.0	0.0
Net cash used in investing activities	(178.6)	(26.3)
Cash Flows From Financing Activities:
Issuance of external debt	0.0	0.0
Repayment of external debt and capital leases	0.0	0.0
Debt financing costs	0.0	0.0
Excess tax benefit from share-based compensation	0.0	0.0
Proceeds from exercise of share options	29.7	19.9
Repurchase of shares	(15.4)	(1.9)
Intercompany loan borrowings, net	0.0	(2.4)
Capital contribution	0.0	0.0
Other	0.0	0.0
Net cash provided by financing activities	14.3	15.6
Effect of currency rate changes on cash	0.0	0.0
Net increase (decrease) in cash and cash equivalents	(0.1)	(0.8)
Cash and cash equivalents at beginning of period	0.3	1.2
Cash and cash equivalents at end of period	0.2	0.4
Mallinckrodt International Finance S.A.
Cash Flows From Operating Activities:
Net cash provided by (used in) operating activities	(84.0)	(39.2)
Cash Flows From Investing Activities:
Capital expenditures	0.0	0.0
Intercompany loan investment	0.0	2.4
Investment in subsidiary	(1,659.9)	(1,300.0)
Acquisitions and intangibles, net of cash acquired	0.0	0.0
Restricted cash	0.0	0.0
Other	0.0	0.0
Net cash used in investing activities	(1,659.9)	(1,297.6)
Cash Flows From Financing Activities:
Issuance of external debt	1,640.0	1,296.8
Repayment of external debt and capital leases	(253.3)	0.0
Debt financing costs	(25.0)	(32.2)
Excess tax benefit from share-based compensation	0.0	0.0
Proceeds from exercise of share options	0.0	0.0
Repurchase of shares	0.0	0.0
Intercompany loan borrowings, net	413.6	140.8
Capital contribution	0.0	0.0
Other	0.0	0.0
Net cash provided by financing activities	1,775.3	1,405.4
Effect of currency rate changes on cash	0.0	0.0
Net increase (decrease) in cash and cash equivalents	31.4	68.6
Cash and cash equivalents at beginning of period	18.5	56.5
Cash and cash equivalents at end of period	49.9	125.1
Other Subsidiaries
Cash Flows From Operating Activities:
Net cash provided by (used in) operating activities	479.0	197.4
Cash Flows From Investing Activities:
Capital expenditures	(92.5)	(80.1)
Intercompany loan investment	(235.0)	(114.5)
Investment in subsidiary	0.0	0.0
Acquisitions and intangibles, net of cash acquired	(1,176.3)	(1,303.2)
Restricted cash	(21.9)	4.1
Other	2.6	8.7
Net cash used in investing activities	(1,523.1)	(1,485.0)
Cash Flows From Financing Activities:
Issuance of external debt	80.0	0.0
Repayment of external debt and capital leases	(1,204.5)	(31.2)
Debt financing costs	(0.3)	0.0
Excess tax benefit from share-based compensation	30.4	5.2
Proceeds from exercise of share options	0.0	0.0
Repurchase of shares	0.0	0.0
Intercompany loan borrowings, net	0.0	0.0
Capital contribution	1,659.9	1,300.0
Other	28.1	0.0
Net cash provided by financing activities	537.4	1,274.0
Effect of currency rate changes on cash	(7.1)	(1.8)
Net increase (decrease) in cash and cash equivalents	(513.8)	(15.4)
Cash and cash equivalents at beginning of period	689.0	217.8
Cash and cash equivalents at end of period	175.2	202.4
Eliminations
Cash Flows From Operating Activities:
Net cash provided by (used in) operating activities	0.0	0.0
Cash Flows From Investing Activities:
Capital expenditures	0.0	0.0
Intercompany loan investment	413.6	138.4
Investment in subsidiary	1,659.9	1,300.0
Acquisitions and intangibles, net of cash acquired	0.0	0.0
Restricted cash	0.0	0.0
Other	0.0	0.0
Net cash used in investing activities	2,073.5	1,438.4
Cash Flows From Financing Activities:
Issuance of external debt	0.0	0.0
Repayment of external debt and capital leases	0.0	0.0
Debt financing costs	0.0	0.0
Excess tax benefit from share-based compensation	0.0	0.0
Proceeds from exercise of share options	0.0	0.0
Repurchase of shares	0.0	0.0
Intercompany loan borrowings, net	(413.6)	(138.4)
Capital contribution	(1,659.9)	(1,300.0)
Other	0.0	0.0
Net cash provided by financing activities	(2,073.5)	(1,438.4)
Effect of currency rate changes on cash	0.0	0.0
Net increase (decrease) in cash and cash equivalents	0.0	0.0
Cash and cash equivalents at beginning of period	0.0	0.0
Cash and cash equivalents at end of period	$ 0.0	$ 0.0