Condensed Consolidating Financial Statements (Schedule of Condensed Consolidating Balance Sheets) (Details) - USD ($) $ in Millions	Dec. 25, 2015	Sep. 25, 2015	Dec. 26, 2014	Sep. 26, 2014
Current Assets:
Cash and cash equivalents	$ 521.9	$ 365.9	$ 899.0	$ 707.8
Accounts receivable, net	485.9	548.5
Inventories	284.9	281.8
Deferred income taxes	116.3	142.7
Prepaid expenses and other current assets	215.6	207.3
Current assets held for sale	0.8	299.9
Intercompany receivables	0.0	0.0
Total current assets	1,625.4	1,846.1
Property, plant and equipment, net	993.0	991.3
Goodwill	3,645.2	3,649.4
Intangible assets, net	9,491.7	9,666.3
Investment in subsidiaries	0.0	0.0
Intercompany loans receivable	0.0	0.0
Other assets	284.0	251.0
Total Assets	16,039.3	16,404.1
Current Liabilities:
Current maturities of long-term debt	21.9	22.3
Accounts payable	118.2	133.0
Accrued payroll and payroll-related costs	79.6	103.7
Interest Payable	72.7	80.2
Accrued and other current liabilities	592.5	517.4
Disposal Group, Including Discontinued Operation, Liabilities, Current	3.4	72.8
Intercompany payables	0.0	0.0
Total current liabilities	888.3	929.4
Long-term debt	6,409.6	6,474.3
Pension and postretirement benefits	114.9	116.7
Environmental liabilities	72.0	73.3
Deferred income taxes	2,999.0	3,132.4
Other income tax liabilities	109.8	121.3
Intercompany loans payable	0.0	0.0
Other liabilities	253.1	245.5
Total Liabilities	10,846.7	11,092.9
Shareholders' Equity	5,192.6	5,311.2
Total Liabilities and Shareholders' Equity	16,039.3	16,404.1
Mallinckrodt plc
Current Assets:
Cash and cash equivalents	0.3	0.1	1.2	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	0.9	1.3
Current assets held for sale	0.0	0.0
Intercompany receivables	39.0	39.1
Total current assets	40.2	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	14,942.3	14,797.7
Intercompany loans receivable	0.0	174.4
Other assets	0.0	0.0
Total Assets	14,982.5	15,012.6
Current Liabilities:
Current maturities of long-term debt	0.0	0.0
Accounts payable	0.2	0.0
Accrued payroll and payroll-related costs	0.1	0.1
Interest Payable	0.0	0.0
Accrued and other current liabilities	3.1	1.8
Disposal Group, Including Discontinued Operation, Liabilities, Current	0.0	0.0
Intercompany payables	9,728.1	9,699.5
Total current liabilities	9,731.5	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	58.4	0.0
Other liabilities	0.0	0.0
Total Liabilities	9,789.9	9,701.4
Shareholders' Equity	5,192.6	5,311.2
Total Liabilities and Shareholders' Equity	14,982.5	15,012.6
Mallinckrodt International Finance S.A.
Current Assets:
Cash and cash equivalents	158.5	152.1	139.4	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	0.1	0.2
Current assets held for sale	0.0	0.0
Intercompany receivables	0.5	128.6
Total current assets	159.1	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	18,948.8	18,838.6
Intercompany loans receivable	58.4	0.0
Other assets	0.0	0.1
Total Assets	19,166.3	19,119.6
Current Liabilities:
Current maturities of long-term debt	19.9	20.0
Accounts payable	0.2	0.2
Accrued payroll and payroll-related costs	0.0	0.0
Interest Payable	72.4	77.1
Accrued and other current liabilities	7.3	0.3
Disposal Group, Including Discontinued Operation, Liabilities, Current	0.0	0.0
Intercompany payables	628.5	0.0
Total current liabilities	728.3	97.6
Long-term debt	6,173.5	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	2,001.9	2,672.6
Other liabilities	7.3	0.0
Total Liabilities	8,911.0	9,069.6
Shareholders' Equity	10,255.3	10,050.0
Total Liabilities and Shareholders' Equity	19,166.3	19,119.6
Other Subsidiaries
Current Assets:
Cash and cash equivalents	363.1	213.7	758.4	689.0
Accounts receivable, net	485.9	548.5
Inventories	284.9	281.8
Deferred income taxes	116.3	142.7
Prepaid expenses and other current assets	214.6	205.8
Current assets held for sale	0.8	299.9
Intercompany receivables	10,356.6	9,699.5
Total current assets	11,822.2	11,391.9
Property, plant and equipment, net	993.0	991.3
Goodwill	3,645.2	3,649.4
Intangible assets, net	9,491.7	9,666.3
Investment in subsidiaries	10,255.3	10,050.0
Intercompany loans receivable	2,001.9	2,498.2
Other assets	284.0	250.9
Total Assets	38,493.3	38,498.0
Current Liabilities:
Current maturities of long-term debt	2.0	2.3
Accounts payable	117.8	132.8
Accrued payroll and payroll-related costs	79.5	103.6
Interest Payable	0.3	3.1
Accrued and other current liabilities	582.1	515.3
Disposal Group, Including Discontinued Operation, Liabilities, Current	3.4	72.8
Intercompany payables	39.5	167.7
Total current liabilities	824.6	997.6
Long-term debt	236.1	174.9
Pension and postretirement benefits	114.9	116.7
Environmental liabilities	72.0	73.3
Deferred income taxes	2,999.0	3,132.4
Other income tax liabilities	109.8	121.3
Intercompany loans payable	0.0	0.0
Other liabilities	245.8	245.5
Total Liabilities	4,602.2	4,861.7
Shareholders' Equity	33,891.1	33,636.3
Total Liabilities and Shareholders' Equity	38,493.3	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	0.0
Intercompany receivables	(10,396.1)	(9,867.2)
Total current assets	(10,396.1)	(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	(44,146.4)	(43,686.3)
Intercompany loans receivable	(2,060.3)	(2,672.6)
Other assets	0.0	0.0
Total Assets	(56,602.8)	(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
Interest Payable	0.0	0.0
Accrued and other current liabilities	0.0	0.0
Disposal Group, Including Discontinued Operation, Liabilities, Current	0.0	0.0
Intercompany payables	(10,396.1)	(9,867.2)
Total current liabilities	(10,396.1)	(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	(2,060.3)	(2,672.6)
Other liabilities	0.0	0.0
Total Liabilities	(12,456.4)	(12,539.8)
Shareholders' Equity	(44,146.4)	(43,686.3)
Total Liabilities and Shareholders' Equity	$ (56,602.8)	$ (56,226.1)