Condensed Consolidating Financial Statements (Schedule of Condensed Consolidating Balance Sheets) (Details) - USD ($) $ in Millions	Jun. 24, 2016	Sep. 25, 2015	Jun. 26, 2015	Sep. 26, 2014
Current Assets:
Cash and cash equivalents	$ 521.9	$ 365.9	$ 225.3	$ 707.8
Accounts receivable, net	500.0	548.5
Inventories	357.7	281.8
Deferred income taxes	115.7	142.7
Prepaid expenses and other current assets	131.0	207.3
Current assets held for sale	0.0	299.9
Intercompany receivables	0.0	0.0
Total current assets	1,626.3	1,846.1
Property, plant and equipment, net	1,012.0	991.3
Goodwill	3,645.5	3,649.4
Intangible assets, net	9,258.5	9,666.3
Investment in subsidiaries	0.0	0.0
Intercompany loans receivable	0.0	0.0
Other assets	290.9	251.0
Total Assets	15,833.2	16,404.1
Current Liabilities:
Current maturities of long-term debt	21.7	22.3
Accounts payable	125.4	133.0
Accrued payroll and payroll-related costs	110.5	103.7
Accrued interest	69.9	80.2
Accrued and other current liabilities	642.0	517.4
Current liabilities held for sale	0.0	72.8
Intercompany payables	0.0	0.0
Total current liabilities	969.5	929.4
Long-term debt	6,279.0	6,474.3
Pension and postretirement benefits	136.4	116.7
Environmental liabilities	73.2	73.3
Deferred income taxes	2,772.5	3,132.4
Other income tax liabilities	95.3	121.3
Intercompany loans payable	0.0	0.0
Other liabilities	298.5	245.5
Total Liabilities	10,624.4	11,092.9
Shareholders' Equity	5,208.8	5,311.2
Total Liabilities and Shareholders' Equity	15,833.2	16,404.1
Mallinckrodt plc
Current Assets:
Cash and cash equivalents	0.1	0.1	0.2	0.3
Accounts receivable, net	0.0	0.0
Inventories	0.0	0.0
Deferred income taxes	0.0	0.0
Prepaid expenses and other current assets	0.7	1.3
Current assets held for sale		0.0
Intercompany receivables	69.2	39.1
Total current assets	70.0	40.5
Property, plant and equipment, net	0.0	0.0
Goodwill	0.0	0.0
Intangible assets, net	0.0	0.0
Investment in subsidiaries	7,549.6	14,797.7
Intercompany loans receivable	202.8	174.4
Other assets	0.0	0.0
Total Assets	7,822.4	15,012.6
Current Liabilities:
Current maturities of long-term debt	0.0	0.0
Accounts payable	0.0	0.0
Accrued payroll and payroll-related costs	0.0	0.1
Accrued interest	0.0	0.0
Accrued and other current liabilities	1.3	1.8
Current liabilities held for sale		0.0
Intercompany payables	2,612.3	9,699.5
Total current liabilities	2,613.6	9,701.4
Long-term debt	0.0	0.0
Pension and postretirement benefits	0.0	0.0
Environmental liabilities	0.0	0.0
Deferred income taxes	0.0	0.0
Other income tax liabilities	0.0	0.0
Intercompany loans payable	0.0	0.0
Other liabilities	0.0	0.0
Total Liabilities	2,613.6	9,701.4
Shareholders' Equity	5,208.8	5,311.2
Total Liabilities and Shareholders' Equity	7,822.4	15,012.6
Mallinckrodt International Finance S.A.
Current Assets:
Cash and cash equivalents	88.8	152.1	49.9	18.5
Accounts receivable, net	0.0	0.0
Inventories	0.0	0.0
Deferred income taxes	0.0	0.0
Prepaid expenses and other current assets	0.3	0.2
Current assets held for sale		0.0
Intercompany receivables	14.7	128.6
Total current assets	103.8	280.9
Property, plant and equipment, net	0.0	0.0
Goodwill	0.0	0.0
Intangible assets, net	0.0	0.0
Investment in subsidiaries	20,026.8	18,838.6
Intercompany loans receivable	0.0	0.0
Other assets	0.0	0.1
Total Assets	20,130.6	19,119.6
Current Liabilities:
Current maturities of long-term debt	19.7	20.0
Accounts payable	0.0	0.2
Accrued payroll and payroll-related costs	0.0	0.0
Accrued interest	69.5	77.1
Accrued and other current liabilities	8.6	0.3
Current liabilities held for sale		0.0
Intercompany payables	638.0	0.0
Total current liabilities	735.8	97.6
Long-term debt	6,023.2	6,299.4
Pension and postretirement benefits	0.0	0.0
Environmental liabilities	0.0	0.0
Deferred income taxes	0.0	0.0
Other income tax liabilities	0.0	0.0
Intercompany loans payable	2,549.4	2,672.6
Other liabilities	6.8	0.0
Total Liabilities	9,315.2	9,069.6
Shareholders' Equity	10,815.4	10,050.0
Total Liabilities and Shareholders' Equity	20,130.6	19,119.6
Other Subsidiaries
Current Assets:
Cash and cash equivalents	433.0	213.7	175.2	689.0
Accounts receivable, net	500.0	548.5
Inventories	357.7	281.8
Deferred income taxes	115.7	142.7
Prepaid expenses and other current assets	130.0	205.8
Current assets held for sale		299.9
Intercompany receivables	3,250.2	9,699.5
Total current assets	4,786.6	11,391.9
Property, plant and equipment, net	1,012.0	991.3
Goodwill	3,645.5	3,649.4
Intangible assets, net	9,258.5	9,666.3
Investment in subsidiaries	10,815.4	10,050.0
Intercompany loans receivable	2,346.6	2,498.2
Other assets	290.9	250.9
Total Assets	32,155.5	38,498.0
Current Liabilities:
Current maturities of long-term debt	2.0	2.3
Accounts payable	125.4	132.8
Accrued payroll and payroll-related costs	110.5	103.6
Accrued interest	0.4	3.1
Accrued and other current liabilities	632.1	515.3
Current liabilities held for sale		72.8
Intercompany payables	83.8	167.7
Total current liabilities	954.2	997.6
Long-term debt	255.8	174.9
Pension and postretirement benefits	136.4	116.7
Environmental liabilities	73.2	73.3
Deferred income taxes	2,772.5	3,132.4
Other income tax liabilities	95.3	121.3
Intercompany loans payable	0.0	0.0
Other liabilities	291.7	245.5
Total Liabilities	4,579.1	4,861.7
Shareholders' Equity	27,576.4	33,636.3
Total Liabilities and Shareholders' Equity	32,155.5	38,498.0
Eliminations
Current Assets:
Cash and cash equivalents	0.0	0.0	$ 0.0	$ 0.0
Accounts receivable, net	0.0	0.0
Inventories	0.0	0.0
Deferred income taxes	0.0	0.0
Prepaid expenses and other current assets	0.0	0.0
Current assets held for sale		0.0
Intercompany receivables	(3,334.1)	(9,867.2)
Total current assets	(3,334.1)	(9,867.2)
Property, plant and equipment, net	0.0	0.0
Goodwill	0.0	0.0
Intangible assets, net	0.0	0.0
Investment in subsidiaries	(38,391.8)	(43,686.3)
Intercompany loans receivable	(2,549.4)	(2,672.6)
Other assets	0.0	0.0
Total Assets	(44,275.3)	(56,226.1)
Current Liabilities:
Current maturities of long-term debt	0.0	0.0
Accounts payable	0.0	0.0
Accrued payroll and payroll-related costs	0.0	0.0
Accrued interest	0.0	0.0
Accrued and other current liabilities	0.0	0.0
Current liabilities held for sale		0.0
Intercompany payables	(3,334.1)	(9,867.2)
Total current liabilities	(3,334.1)	(9,867.2)
Long-term debt	0.0	0.0
Pension and postretirement benefits	0.0	0.0
Environmental liabilities	0.0	0.0
Deferred income taxes	0.0	0.0
Other income tax liabilities	0.0	0.0
Intercompany loans payable	(2,549.4)	(2,672.6)
Other liabilities	0.0	0.0
Total Liabilities	(5,883.5)	(12,539.8)
Shareholders' Equity	(38,391.8)	(43,686.3)
Total Liabilities and Shareholders' Equity	$ (44,275.3)	$ (56,226.1)