Guarantor Financial Information (Consolidating Balance Sheets) (Details) - USD ($) $ in Millions	Jun. 30, 2018	Dec. 31, 2017	Jun. 30, 2017	Dec. 31, 2016
Current assets:
Cash and cash equivalents	$ 259.7	$ 472.4	$ 263.7
Restricted cash	35.0	39.4	34.2
Accounts receivable, net	3,005.1	3,009.8
Inventories	3,353.3	3,291.5
Held for sale and other current assets	3,135.3	795.3
Intercompany receivables	0.0	0.0
Short term intercompany loan receivable	0.0	0.0
Total current assets	9,788.4	7,608.4
Investments	527.8	241.1
Property, plant and equipment (PP&E), net	6,426.6	6,635.4
Goodwill	19,043.7	19,831.7	19,482.1	$ 17,888.2
Intangible assets, net	30,110.5	33,046.1	$ 33,434.3	$ 34,697.5
Deferred tax asset	158.3	188.8
Long term intercompany loan receivable	0.0	0.0
Other non-current assets	166.8	205.4
Total assets	66,222.1	67,756.9
Current liabilities:
Accounts payable and accrued expenses	3,888.5	4,184.5
Short term borrowings and capital leases	1,192.9	2,788.7
Intercompany payables	0.0	0.0
Short term intercompany loan payable	0.0	0.0
Other current liabilities	1,225.9	908.8
Total current liabilities	6,307.3	7,882.0
Long term borrowings and capital leases	16,722.0	16,752.4
Deferred tax liability	4,367.3	4,748.2
Long term intercompany loan payable	0.0	0.0
Other non-current liabilities	2,065.1	2,197.9
Total liabilities	29,461.7	31,580.5
Total equity	36,760.4	36,176.4
Total liabilities and equity	66,222.1	67,756.9
Eliminations
Current assets:
Cash and cash equivalents	0.0	0.0
Restricted cash	0.0	0.0
Accounts receivable, net	0.0	0.0
Inventories	0.0	0.0
Held for sale and other current assets	0.0	0.0
Intercompany receivables	(6,372.3)	(4,802.5)
Short term intercompany loan receivable	(1,154.9)	(2,006.3)
Total current assets	(7,527.2)	(6,808.8)
Investments	(95,623.7)	(94,947.2)
Property, plant and equipment (PP&E), net	0.0	0.0
Goodwill	0.0	0.0
Intangible assets, net	0.0	0.0
Deferred tax asset	(304.1)	(304.1)
Long term intercompany loan receivable	(14,331.8)	(13,659.5)
Other non-current assets	0.0	0.0
Total assets	(117,786.8)	(115,719.6)
Current liabilities:
Accounts payable and accrued expenses	0.0	0.0
Short term borrowings and capital leases	0.0	0.0
Intercompany payables	(6,372.3)	(4,802.5)
Short term intercompany loan payable	(1,154.9)	(2,006.3)
Other current liabilities	0.0	0.0
Total current liabilities	(7,527.2)	(6,808.8)
Long term borrowings and capital leases	0.0	0.0
Deferred tax liability	(304.1)	(304.1)
Long term intercompany loan payable	(14,331.8)	(13,659.5)
Other non-current liabilities	0.0	0.0
Total liabilities	(22,163.1)	(20,772.4)
Total equity	(95,623.7)	(94,947.2)
Total liabilities and equity	(117,786.8)	(115,719.6)
Shire plc (Parent Guarantor)
Current assets:
Cash and cash equivalents	0.0	0.0
Restricted cash	0.0	0.0
Accounts receivable, net	0.0	0.0
Inventories	0.0	0.0
Held for sale and other current assets	0.0	0.0
Intercompany receivables	0.0	0.0
Short term intercompany loan receivable	0.0	0.0
Total current assets	0.0	0.0
Investments	44,091.9	43,204.3
Property, plant and equipment (PP&E), net	0.0	0.0
Goodwill	0.0	0.0
Intangible assets, net	0.0	0.0
Deferred tax asset	0.0	0.0
Long term intercompany loan receivable	0.0	0.0
Other non-current assets	0.0	0.0
Total assets	44,091.9	43,204.3
Current liabilities:
Accounts payable and accrued expenses	7.6	0.2
Short term borrowings and capital leases	0.0	0.0
Intercompany payables	3,691.3	3,585.3
Short term intercompany loan payable	0.0	0.0
Other current liabilities	611.4	573.5
Total current liabilities	4,310.3	4,159.0
Long term borrowings and capital leases	0.0	0.0
Deferred tax liability	0.0	0.0
Long term intercompany loan payable	3,021.2	2,868.9
Other non-current liabilities	0.0	0.0
Total liabilities	7,331.5	7,027.9
Total equity	36,760.4	36,176.4
Total liabilities and equity	44,091.9	43,204.3
Baxalta Inc. (Baxalta Notes Subsidiary Issuer and SAIIDAC Notes Subsidiary Guarantor)
Current assets:
Cash and cash equivalents	0.0	0.5
Restricted cash	0.0	0.0
Accounts receivable, net	0.0	0.0
Inventories	0.0	0.0
Held for sale and other current assets	78.9	95.2
Intercompany receivables	0.0	0.0
Short term intercompany loan receivable	0.0	0.0
Total current assets	78.9	95.7
Investments	38,702.9	38,924.6
Property, plant and equipment (PP&E), net	4.8	7.6
Goodwill	0.0	0.0
Intangible assets, net	0.0	0.0
Deferred tax asset	304.1	304.1
Long term intercompany loan receivable	2,276.0	1,609.3
Other non-current assets	0.0	0.0
Total assets	41,366.7	40,941.3
Current liabilities:
Accounts payable and accrued expenses	11.2	18.1
Short term borrowings and capital leases	0.0	748.8
Intercompany payables	2,681.0	1,217.2
Short term intercompany loan payable	0.0	0.0
Other current liabilities	11.9	10.7
Total current liabilities	2,704.1	1,994.8
Long term borrowings and capital leases	4,287.3	4,308.9
Deferred tax liability	0.0	0.0
Long term intercompany loan payable	0.0	0.0
Other non-current liabilities	91.9	70.0
Total liabilities	7,083.3	6,373.7
Total equity	34,283.4	34,567.6
Total liabilities and equity	41,366.7	40,941.3
Non-Guarantor Non-Issuer Subsidiaries
Current assets:
Cash and cash equivalents	259.7	471.9
Restricted cash	35.0	39.4
Accounts receivable, net	3,005.1	3,009.8
Inventories	3,353.3	3,291.5
Held for sale and other current assets	3,054.9	698.5
Intercompany receivables	6,260.4	4,682.3
Short term intercompany loan receivable	0.0	0.0
Total current assets	15,968.4	12,193.4
Investments	13,356.7	13,059.4
Property, plant and equipment (PP&E), net	6,421.8	6,627.8
Goodwill	19,043.7	19,831.7
Intangible assets, net	30,110.5	33,046.1
Deferred tax asset	158.3	188.8
Long term intercompany loan receivable	0.0	0.0
Other non-current assets	164.7	202.6
Total assets	85,224.1	85,149.8
Current liabilities:
Accounts payable and accrued expenses	3,785.0	4,080.3
Short term borrowings and capital leases	38.0	33.6
Intercompany payables	0.0	0.0
Short term intercompany loan payable	1,154.9	2,006.3
Other current liabilities	602.6	324.6
Total current liabilities	5,580.5	6,444.8
Long term borrowings and capital leases	378.9	393.3
Deferred tax liability	4,671.4	5,052.3
Long term intercompany loan payable	11,310.6	10,790.6
Other non-current liabilities	1,973.2	2,127.9
Total liabilities	23,914.6	24,808.9
Total equity	61,309.5	60,340.9
Total liabilities and equity	85,224.1	85,149.8
Non-Guarantor Subsidiaries of Baxalta Notes
Current assets:
Cash and cash equivalents	259.7	471.9
Restricted cash	35.0	39.4
Accounts receivable, net	3,005.1	3,009.8
Inventories	3,353.3	3,291.5
Held for sale and other current assets	3,056.4	700.1
Intercompany receivables	6,372.3	4,802.5
Short term intercompany loan receivable	1,154.9	2,006.3
Total current assets	17,236.7	14,321.5
Investments	13,356.7	13,059.4
Property, plant and equipment (PP&E), net	6,421.8	6,627.8
Goodwill	19,043.7	19,831.7
Intangible assets, net	30,110.5	33,046.1
Deferred tax asset	158.3	188.8
Long term intercompany loan receivable	12,055.8	12,050.2
Other non-current assets	166.8	205.4
Total assets	98,550.3	99,330.9
Current liabilities:
Accounts payable and accrued expenses	3,869.7	4,166.2
Short term borrowings and capital leases	1,192.9	2,039.9
Intercompany payables	0.0	0.0
Short term intercompany loan payable	1,154.9	2,006.3
Other current liabilities	602.6	324.6
Total current liabilities	6,820.1	8,537.0
Long term borrowings and capital leases	12,434.7	12,443.5
Deferred tax liability	4,671.4	5,052.3
Long term intercompany loan payable	11,310.6	10,790.6
Other non-current liabilities	1,973.2	2,127.9
Total liabilities	37,210.0	38,951.3
Total equity	61,340.3	60,379.6
Total liabilities and equity	98,550.3	99,330.9
SAIIDAC (SAIIDAC Notes Subsidiary Issuer)
Current assets:
Cash and cash equivalents	0.0	0.0
Restricted cash	0.0	0.0
Accounts receivable, net	0.0	0.0
Inventories	0.0	0.0
Held for sale and other current assets	1.5	1.6
Intercompany receivables	111.9	120.2
Short term intercompany loan receivable	1,154.9	2,006.3
Total current assets	1,268.3	2,128.1
Investments	0.0	0.0
Property, plant and equipment (PP&E), net	0.0	0.0
Goodwill	0.0	0.0
Intangible assets, net	0.0	0.0
Deferred tax asset	0.0	0.0
Long term intercompany loan receivable	12,055.8	12,050.2
Other non-current assets	2.1	2.8
Total assets	13,326.2	14,181.1
Current liabilities:
Accounts payable and accrued expenses	84.7	85.9
Short term borrowings and capital leases	1,154.9	2,006.3
Intercompany payables	0.0	0.0
Short term intercompany loan payable	0.0	0.0
Other current liabilities	0.0	0.0
Total current liabilities	1,239.6	2,092.2
Long term borrowings and capital leases	12,055.8	12,050.2
Deferred tax liability	0.0	0.0
Long term intercompany loan payable	0.0	0.0
Other non-current liabilities	0.0	0.0
Total liabilities	13,295.4	14,142.4
Total equity	30.8	38.7
Total liabilities and equity	$ 13,326.2	$ 14,181.1