Guarantor Financial Information (Consolidating Statements of Income) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Revenues:
Product sales	$ 3,533.8	$ 3,315.4	$ 10,537.9	$ 7,264.8
Royalties and other revenues	163.8	136.7	477.8	325.7
Total revenues	3,697.6	3,452.1	11,015.7	7,590.5
Costs and expenses:
Cost of sales	1,001.4	1,736.2	3,437.3	2,762.9
Research and development	402.8	511.1	1,324.5	1,023.0
Selling, general and administrative	859.7	875.6	2,647.7	2,025.8
Amortization of acquired intangible assets	482.4	354.9	1,280.5	702.5
Integration and acquisition costs	237.0	284.5	696.7	738.6
Reorganization costs	5.4	101.4	24.5	115.7
Gain/(loss) on sale of product rights	0.3	(5.7)	(0.4)	(12.2)
Total operating expenses	2,989.0	3,858.0	9,410.8	7,356.3
Operating income/(loss) from continuing operations	708.6	(405.9)	1,604.9	234.2
Interest (expense)/income, net	(140.3)	(177.6)	(419.7)	(306.9)
Other income/(expense), net	(0.2)	(13.7)	6.8	(16.2)
Total other expense, net	(140.5)	(191.3)	(412.9)	(323.1)
Income/(loss) from continuing operations before income taxes and equity in (losses)/earnings of equity method investees	568.1	(597.2)	1,192.0	(88.9)
Income taxes	(13.5)	229.6	(44.6)	218.4
Equity in income/(losses) of equity method investees, net of taxes	(3.4)	(0.9)	0.1	(1.9)
Income/(loss) from continuing operations, net of taxes	551.2	(368.5)	1,147.5	127.6
(Loss)/gain from discontinued operations, net of taxes	(0.4)	(18.3)	18.6	(257.5)
Net income/(loss)	550.8	(386.8)	1,166.1	(129.9)
Comprehensive income/(loss)	1,319.8	(135.2)	3,632.8	(80.3)
Eliminations
Revenues:
Product sales	0.0	0.0	0.0	0.0
Royalties and other revenues	0.0	0.0	0.0	0.0
Total revenues	0.0	0.0	0.0	0.0
Costs and expenses:
Cost of sales	0.0	0.0	0.0	0.0
Research and development	0.0	0.0	0.0	0.0
Selling, general and administrative	0.0	0.0	0.0	0.0
Amortization of acquired intangible assets	0.0	0.0	0.0	0.0
Integration and acquisition costs	0.0	0.0	0.0	0.0
Reorganization costs	0.0	0.0	0.0	0.0
Gain/(loss) on sale of product rights	0.0	0.0	0.0	0.0
Total operating expenses	0.0	0.0	0.0	0.0
Operating income/(loss) from continuing operations	0.0	0.0	0.0	0.0
Interest (expense)/income, net	0.0	0.0	0.0	0.0
Other income/(expense), net	0.0	0.0	0.0	0.0
Total other expense, net	0.0	0.0	0.0	0.0
Income/(loss) from continuing operations before income taxes and equity in (losses)/earnings of equity method investees	0.0	0.0	0.0	0.0
Income taxes	0.0	0.0	0.0	0.0
Equity in income/(losses) of equity method investees, net of taxes	(524.3)	871.0	(1,340.9)	667.5
Income/(loss) from continuing operations, net of taxes	(524.3)	871.0	(1,340.9)	667.5
(Loss)/gain from discontinued operations, net of taxes	0.0	0.0	0.0	0.0
Net income/(loss)	(524.3)	871.0	(1,340.9)	667.5
Comprehensive income/(loss)	(1,995.8)	871.0	(6,130.6)	1,055.8
Shire plc (Parent Guarantor)
Revenues:
Product sales	0.0	0.0	0.0	0.0
Royalties and other revenues	0.0	0.0	0.0	0.0
Total revenues	0.0	0.0	0.0	0.0
Costs and expenses:
Cost of sales	0.0	0.0	0.0	0.0
Research and development	0.0	0.0	0.0	0.0
Selling, general and administrative	6.1	(2.5)	24.2	33.3
Amortization of acquired intangible assets	0.0	0.0	0.0	0.0
Integration and acquisition costs	0.0		164.7	0.0
Reorganization costs	0.0	0.0	0.0	0.0
Gain/(loss) on sale of product rights	0.0	0.0	0.0	0.0
Total operating expenses	6.1	(2.5)	188.9	33.3
Operating income/(loss) from continuing operations	(6.1)	2.5	(188.9)	(33.3)
Interest (expense)/income, net	(48.0)	(23.2)	(109.1)	(67.7)
Other income/(expense), net	0.0	(0.1)	1.8	0.8
Total other expense, net	(48.0)	(23.3)	(107.3)	(66.9)
Income/(loss) from continuing operations before income taxes and equity in (losses)/earnings of equity method investees	(54.1)	(20.8)	(296.2)	(100.2)
Income taxes	0.9	0.0	1.7	1.9
Equity in income/(losses) of equity method investees, net of taxes	604.0	(366.0)	1,460.6	(31.6)
Income/(loss) from continuing operations, net of taxes	550.8	(386.8)	1,166.1	(129.9)
(Loss)/gain from discontinued operations, net of taxes	0.0	0.0	0.0	0.0
Net income/(loss)	550.8	(386.8)	1,166.1	(129.9)
Comprehensive income/(loss)	1,319.8	(135.2)	3,632.8	(80.3)
SAIIDAC (SAIIDAC Notes Subsidiary Issuer)
Revenues:
Product sales	0.0	0.0	0.0	0.0
Royalties and other revenues	0.0	0.0	0.0	0.0
Total revenues	0.0	0.0	0.0	0.0
Costs and expenses:
Cost of sales	0.0	0.0	0.0	0.0
Research and development	0.0	0.0	0.0	0.0
Selling, general and administrative	0.0	0.0	0.0	0.0
Amortization of acquired intangible assets	0.0	0.0	0.0	0.0
Integration and acquisition costs	0.0	0.0	0.0	0.0
Reorganization costs	0.0	0.0	0.0	0.0
Gain/(loss) on sale of product rights	0.0	0.0	0.0	0.0
Total operating expenses	0.0	0.0	0.0	0.0
Operating income/(loss) from continuing operations	0.0	0.0	0.0	0.0
Interest (expense)/income, net	3.0	61.7	14.5	41.5
Other income/(expense), net	0.0	0.0	0.0	0.0
Total other expense, net	3.0	61.7	14.5	41.5
Income/(loss) from continuing operations before income taxes and equity in (losses)/earnings of equity method investees	3.0	61.7	14.5	41.5
Income taxes	0.6	(15.4)	(3.6)	(10.3)
Equity in income/(losses) of equity method investees, net of taxes	0.0	0.0	0.0	0.0
Income/(loss) from continuing operations, net of taxes	3.6	46.3	10.9	31.2
(Loss)/gain from discontinued operations, net of taxes	0.0	0.0	0.0	0.0
Net income/(loss)	3.6	46.3	10.9	31.2
Comprehensive income/(loss)	3.6	46.3	10.9	31.2
Baxalta Inc. (Baxalta Notes Subsidiary Issuer and SAIIDAC Notes Subsidiary Guarantor)
Revenues:
Product sales	0.0	0.0	0.0	0.0
Royalties and other revenues	0.0	0.0	0.0	0.0
Total revenues	0.0	0.0	0.0	0.0
Costs and expenses:
Cost of sales	0.0	0.0	0.0	0.0
Research and development	0.0	0.0	0.0	0.4
Selling, general and administrative	4.0	10.8	15.3	19.4
Amortization of acquired intangible assets	0.0	0.0	0.0	0.0
Integration and acquisition costs	9.2	50.0	52.3	259.7
Reorganization costs	0.0	0.0	0.0	0.0
Gain/(loss) on sale of product rights	0.0	0.0	0.0	0.0
Total operating expenses	13.2	60.8	67.6	279.5
Operating income/(loss) from continuing operations	(13.2)	(60.8)	(67.6)	(279.5)
Interest (expense)/income, net	(23.6)	(26.1)	(66.5)	(32.4)
Other income/(expense), net	4.4	(0.1)	4.3	7.6
Total other expense, net	(19.2)	(26.2)	(62.2)	(24.8)
Income/(loss) from continuing operations before income taxes and equity in (losses)/earnings of equity method investees	(32.4)	(87.0)	(129.8)	(304.3)
Income taxes	(8.9)	18.9	(45.0)	77.7
Equity in income/(losses) of equity method investees, net of taxes	(79.8)	(505.0)	(119.7)	(635.9)
Income/(loss) from continuing operations, net of taxes	(121.1)	(573.1)	(294.5)	(862.5)
(Loss)/gain from discontinued operations, net of taxes	0.0	0.0	0.0	0.0
Net income/(loss)	(121.1)	(573.1)	(294.5)	(862.5)
Comprehensive income/(loss)	581.0	(333.4)	2,031.5	(809.0)
Non-Guarantor Non-Issuer Subsidiaries
Revenues:
Product sales	3,533.8	3,315.4	10,537.9	7,264.8
Royalties and other revenues	163.8	136.7	477.8	325.7
Total revenues	3,697.6	3,452.1	11,015.7	7,590.5
Costs and expenses:
Cost of sales	1,001.4	1,736.2	3,437.3	2,762.9
Research and development	402.8	511.1	1,324.5	1,022.6
Selling, general and administrative	849.6	867.3	2,608.2	1,973.1
Amortization of acquired intangible assets	482.4	354.9	1,280.5	702.5
Integration and acquisition costs	227.8	234.5	479.7	478.9
Reorganization costs	5.4	101.4	24.5	115.7
Gain/(loss) on sale of product rights	0.3	(5.7)	(0.4)	(12.2)
Total operating expenses	2,969.7	3,799.7	9,154.3	7,043.5
Operating income/(loss) from continuing operations	727.9	(347.6)	1,861.4	547.0
Interest (expense)/income, net	(71.7)	(190.0)	(258.6)	(248.3)
Other income/(expense), net	(4.6)	(13.5)	0.7	(24.6)
Total other expense, net	(76.3)	(203.5)	(257.9)	(272.9)
Income/(loss) from continuing operations before income taxes and equity in (losses)/earnings of equity method investees	651.6	(551.1)	1,603.5	274.1
Income taxes	(6.1)	226.1	2.3	149.1
Equity in income/(losses) of equity method investees, net of taxes	(3.3)	(0.9)	0.1	(1.9)
Income/(loss) from continuing operations, net of taxes	642.2	(325.9)	1,605.9	421.3
(Loss)/gain from discontinued operations, net of taxes	(0.4)	(18.3)	18.6	(257.5)
Net income/(loss)	641.8	(344.2)	1,624.5	163.8
Comprehensive income/(loss)	1,411.2	(583.9)	4,088.2	(278.0)
Non-Guarantor Subsidiaries of Baxalta Notes
Revenues:
Product sales	3,533.8	3,315.4	10,537.9	7,264.8
Royalties and other revenues	163.8	136.7	477.8	325.7
Total revenues	3,697.6	3,452.1	11,015.7	7,590.5
Costs and expenses:
Cost of sales	1,001.4	1,736.2	3,437.3	2,762.9
Research and development	402.8	511.1	1,324.5	1,022.6
Selling, general and administrative	849.6	867.3	2,608.2	1,973.1
Amortization of acquired intangible assets	482.4	354.9	1,280.5	702.5
Integration and acquisition costs	227.8	234.5	479.7	478.9
Reorganization costs	5.4	101.4	24.5	115.7
Gain/(loss) on sale of product rights	0.3	(5.7)	(0.4)	(12.2)
Total operating expenses	2,969.7	3,799.7	9,154.3	7,043.5
Operating income/(loss) from continuing operations	727.9	(347.6)	1,861.4	547.0
Interest (expense)/income, net	(68.7)	(128.3)	(244.1)	(206.8)
Other income/(expense), net	(4.6)	(13.5)	0.7	(24.6)
Total other expense, net	(73.3)	(141.8)	(243.4)	(231.4)
Income/(loss) from continuing operations before income taxes and equity in (losses)/earnings of equity method investees	654.6	(489.4)	1,618.0	315.6
Income taxes	(5.5)	210.7	(1.3)	138.8
Equity in income/(losses) of equity method investees, net of taxes	(3.3)	(0.9)	0.1	(1.9)
Income/(loss) from continuing operations, net of taxes	645.8	(279.6)	1,616.8	452.5
(Loss)/gain from discontinued operations, net of taxes	(0.4)	(18.3)	18.6	(257.5)
Net income/(loss)	645.4	(297.9)	1,635.4	195.0
Comprehensive income/(loss)	$ 1,414.8	$ (537.6)	$ 4,099.1	$ (246.8)