Condensed Consolidating Financial Statements (Schedule of Condensed Consolidating Balance Sheets) (Details) - USD ($) $ in Millions	Sep. 29, 2017	Dec. 30, 2016	Sep. 30, 2016
Current Assets:
Cash and cash equivalents	$ 371.8	$ 342.0	$ 280.5
Accounts receivable, net	464.3	431.0
Inventories	341.3	350.7
Prepaid expenses and other current assets	121.1	131.9
Notes receivable	154.0	0.0
Current assets held for sale	0.0	310.9
Intercompany receivables	0.0	0.0
Total current assets	1,452.5	1,566.5
Property, plant and equipment, net	962.4	881.5
Goodwill	3,459.5	3,498.1
Intangible assets, net	8,545.9	9,000.5
Investment in subsidiaries	0.0	0.0
Intercompany loans receivable	0.0	0.0
Other assets	191.6	259.7
Total Assets	14,611.9	15,206.3
Current Liabilities:
Current maturities of long-term debt	318.2	271.2
Accounts payable	104.9	112.1
Accrued payroll and payroll-related costs	84.4	76.1
Accrued interest	78.1	68.7
Income taxes payable	28.1	101.7
Accrued and other current liabilities	440.4	557.1
Current liabilities held for sale	0.0	120.3
Intercompany payables	0.0	0.0
Total current liabilities	1,054.1	1,307.2
Long-term debt	5,517.4	5,880.8
Pension and postretirement benefits	67.5	136.4
Environmental liabilities	73.1	73.0
Deferred income taxes	2,294.1	2,398.1
Other income tax liabilities	78.5	70.4
Intercompany loans payable	0.0	0.0
Other liabilities	414.2	356.1
Total Liabilities	9,498.9	10,222.0
Shareholders' Equity	5,113.0	4,984.3
Total Liabilities and Shareholders' Equity	14,611.9	15,206.3
Mallinckrodt plc
Current Assets:
Cash and cash equivalents	0.7	0.5	0.3
Accounts receivable, net	0.0	0.0
Inventories	0.0	0.0
Prepaid expenses and other current assets	0.3	1.0
Notes receivable	0.0	0.0
Current assets held for sale	0.0	0.0
Intercompany receivables	127.9	59.7
Total current assets	128.9	61.2
Property, plant and equipment, net	0.0	0.0
Goodwill	0.0	0.0
Intangible assets, net	0.0	0.0
Investment in subsidiaries	4,923.4	5,534.1
Intercompany loans receivable	744.8	3.5
Other assets	0.0	0.0
Total Assets	5,797.1	5,598.8
Current Liabilities:
Current maturities of long-term debt	0.0	0.0
Accounts payable	0.0	0.1
Accrued payroll and payroll-related costs	0.0	0.0
Accrued interest	0.0	0.0
Income taxes payable	0.0	0.0
Accrued and other current liabilities	1.3	1.9
Current liabilities held for sale	0.0	0.0
Intercompany payables	682.8	612.5
Total current liabilities	684.1	614.5
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	684.1	614.5
Shareholders' Equity	5,113.0	4,984.3
Total Liabilities and Shareholders' Equity	5,797.1	5,598.8
Mallinckrodt International Finance S.A.
Current Assets:
Cash and cash equivalents	37.6	44.5	25.0
Accounts receivable, net	0.0	0.0
Inventories	0.0	0.0
Prepaid expenses and other current assets	0.2	0.0
Notes receivable	0.0	0.0
Current assets held for sale	0.0	0.0
Intercompany receivables	246.8	65.1
Total current assets	284.6	109.6
Property, plant and equipment, net	0.0	0.0
Goodwill	0.0	0.0
Intangible assets, net	0.0	0.0
Investment in subsidiaries	21,531.2	20,624.1
Intercompany loans receivable	0.0	0.0
Other assets	0.0	0.0
Total Assets	21,815.8	20,733.7
Current Liabilities:
Current maturities of long-term debt	318.0	19.7
Accounts payable	0.0	0.1
Accrued payroll and payroll-related costs	0.0	0.0
Accrued interest	77.5	53.9
Income taxes payable	0.0	0.0
Accrued and other current liabilities	0.4	7.5
Current liabilities held for sale	0.0	0.0
Intercompany payables	0.0	467.1
Total current liabilities	395.9	548.3
Long-term debt	5,303.3	5,860.6
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	5,454.8	3,329.4
Other liabilities	7.7	7.0
Total Liabilities	11,161.7	9,745.3
Shareholders' Equity	10,654.1	10,988.4
Total Liabilities and Shareholders' Equity	21,815.8	20,733.7
Other Subsidiaries
Current Assets:
Cash and cash equivalents	333.5	297.0	255.2
Accounts receivable, net	464.3	431.0
Inventories	341.3	350.7
Prepaid expenses and other current assets	120.6	130.9
Notes receivable	154.0	0.0
Current assets held for sale	0.0	310.9
Intercompany receivables	694.1	1,081.3
Total current assets	2,107.8	2,601.8
Property, plant and equipment, net	962.4	881.5
Goodwill	3,459.5	3,498.1
Intangible assets, net	8,545.9	9,000.5
Investment in subsidiaries	10,654.1	10,988.5
Intercompany loans receivable	4,710.0	3,325.9
Other assets	191.6	259.7
Total Assets	30,631.3	30,556.0
Current Liabilities:
Current maturities of long-term debt	0.2	251.5
Accounts payable	104.9	111.9
Accrued payroll and payroll-related costs	84.4	76.1
Accrued interest	0.6	14.8
Income taxes payable	28.1	101.7
Accrued and other current liabilities	438.7	547.7
Current liabilities held for sale	0.0	120.3
Intercompany payables	386.0	126.5
Total current liabilities	1,042.9	1,350.5
Long-term debt	214.1	20.2
Pension and postretirement benefits	67.5	136.4
Environmental liabilities	73.1	73.0
Deferred income taxes	2,294.1	2,398.1
Other income tax liabilities	78.5	70.4
Intercompany loans payable	0.0	0.0
Other liabilities	406.5	349.1
Total Liabilities	4,176.7	4,397.7
Shareholders' Equity	26,454.6	26,158.3
Total Liabilities and Shareholders' Equity	30,631.3	30,556.0
Eliminations
Current Assets:
Cash and cash equivalents	0.0	0.0	$ 0.0
Accounts receivable, net	0.0	0.0
Inventories	0.0	0.0
Prepaid expenses and other current assets	0.0	0.0
Notes receivable	0.0	0.0
Current assets held for sale	0.0	0.0
Intercompany receivables	(1,068.8)	(1,206.1)
Total current assets	(1,068.8)	(1,206.1)
Property, plant and equipment, net	0.0	0.0
Goodwill	0.0	0.0
Intangible assets, net	0.0	0.0
Investment in subsidiaries	(37,108.7)	(37,146.7)
Intercompany loans receivable	(5,454.8)	(3,329.4)
Other assets	0.0	0.0
Total Assets	(43,632.3)	(41,682.2)
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
Income taxes payable	0.0	0.0
Accrued and other current liabilities	0.0	0.0
Current liabilities held for sale	0.0	0.0
Intercompany payables	(1,068.8)	(1,206.1)
Total current liabilities	(1,068.8)	(1,206.1)
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	(5,454.8)	(3,329.4)
Other liabilities	0.0	0.0
Total Liabilities	(6,523.6)	(4,535.5)
Shareholders' Equity	(37,108.7)	(37,146.7)
Total Liabilities and Shareholders' Equity	(43,632.3)	(41,682.2)
Ordinary A
Condensed Consolidating Financial Statements
Ordinary A shares	$ 0.0	$ 0.0