BUSINESS COMBINATIONS - Narrative (Details)				1 Months Ended	3 Months Ended			6 Months Ended		12 Months Ended
	Apr. 01, 2015 USD ($) product $ / shares	Feb. 23, 2015 USD ($)	Jan. 23, 2014 USD ($) $ / shares	May. 31, 2015	Jun. 30, 2015 USD ($)	Sep. 30, 2014 USD ($)	Jun. 30, 2014 USD ($)	Jun. 30, 2015 USD ($)	Jun. 30, 2014 USD ($)	Dec. 31, 2014 USD ($)	Mar. 31, 2015	Feb. 10, 2015 USD ($)	Jul. 07, 2014 USD ($)
Business Acquisition [Line Items]
Acquisition-related contingent consideration					$ 191,400,000			$ 191,400,000		$ 141,800,000
Purchase price net of cash received					13,090,900,000		$ 68,000,000	13,885,900,000	$ 374,300,000
Acquisition of businesses, contingent and deferred consideration obligations at fair value					387,700,000		27,400,000	674,600,000	49,100,000
Acquisition-related costs					9,500,000		600,000	19,300,000	2,100,000
Pro forma acquisition accounting adjustment on inventory sold subsequent to acquisition date					45,000,000		$ 3,000,000	69,000,000	$ 8,000,000
1.5% Convertible Notes Due March 2019 | Convertible Debt
Business Acquisition [Line Items]
Estimated fair value of warrant transactions	$ 1,080,000,000
Stated interest rate on debt (as a percent)	1.50%										1.50%
2.75% Convertible Notes Due May 2015 | Convertible Debt
Business Acquisition [Line Items]
Stated interest rate on debt (as a percent)	2.75%										2.75%
Salix
Business Acquisition [Line Items]
Inventory adjustments	$ 108,000,000
Estimated fair value of derivatives	$ 1,270,000,000
Weighted- average useful lives (Years)	11 years
Estimated cost to complete development	$ 90,000,000
Accrual for potential losses and legal costs	336,000,000
Accrual for returns and rebates	251,000,000
Range of potential milestone payments, low	0
Range of potential milestone payment, high	650,000,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Contingent Liability	327,900,000
Acquisition related contingent consideration, current	$ 11,000,000
Number of products in product portfolio (more than) | product	20
Deferred tax assets	$ 237,000,000
Deferred tax liabilities	$ 3,750,000,000
Par value per share of common stock (in dollars per share) | $ / shares	$ 0.001
Aggregate purchase price	$ 13,132,000,000
Current liabilities	$ 1,764,200,000
Acquisition-related costs					13,000,000			13,000,000
Revenues of acquiree since acquisition date								313,000,000
Net earnings (loss), net of tax of acquiree since acquisition date								$ (200,000,000)
Per share consideration (in usd per share) | $ / shares	$ 173.00
Estimated insurance recoveries	$ 80,000,000
Salix | Xifaxan [Member]
Business Acquisition [Line Items]
IPR&D asset fair value	$ 4,790,000,000
Salix | 1.5% Convertible Notes Due March 2019 | Convertible Debt
Business Acquisition [Line Items]
Stated interest rate on debt (as a percent)	1.50%
Salix | 2.75% Convertible Notes Due May 2015 | Convertible Debt
Business Acquisition [Line Items]
Stated interest rate on debt (as a percent)	2.75%
Other 2015 Acquisitions
Business Acquisition [Line Items]
Weighted- average useful lives (Years)								8 years
Aggregate purchase price					1,071,900,000			$ 1,071,900,000
Acquisition of businesses, contingent and deferred consideration obligations at fair value								112,000,000
Current liabilities					92,800,000			92,800,000
Non-current liabilities					96,000,000			96,000,000
Acquisition-related costs								7,000,000
Revenues of acquiree since acquisition date								366,000,000
Net earnings (loss), net of tax of acquiree since acquisition date								91,000,000
Dendreon
Business Acquisition [Line Items]
Purchase price net of cash received		$ 415,000,000
Gross purchase price		495,000,000
Cash received from Acquisition		80,000,000
Stock consideration transferred		$ 50,000,000
Marathon
Business Acquisition [Line Items]
Acquisition-related contingent consideration					6,000,000			$ 6,000,000
Aggregate purchase price												$ 286,000,000
Assumed liability owed to a third party												64,000,000
Current liabilities												41,000,000
Non-current liabilities												$ 46,000,000
2014 Acquisitions
Business Acquisition [Line Items]
Weighted- average useful lives (Years)								10 years
Acquisition of businesses, contingent and deferred consideration obligations at fair value										133,000,000
Current liabilities					$ 173,800,000			$ 173,800,000
Total fair value of consideration transferred										$ 1,420,000,000
PreCision Dermatology, Inc.
Business Acquisition [Line Items]
Acquisition-related contingent consideration													$ 25,000,000
Aggregate purchase price													$ 459,000,000
PreCision Dermatology, Inc. | Other (Income) Expense
Business Acquisition [Line Items]
Post-combination expense						$ 20,000,000
Solta Medical, Inc.
Business Acquisition [Line Items]
Aggregate purchase price			$ 293,000,000
Per share consideration (in usd per share) | $ / shares			$ 2.92
Repayments of long-term debt			$ 44,000,000
Restricted Stock | Salix
Business Acquisition [Line Items]
Per share consideration (in usd per share) | $ / shares	$ 173.00
Development and Sales Based Milestones | Salix
Business Acquisition [Line Items]
Range of potential milestone payment, high	$ 250,000,000
Acquired IPR&D | Salix
Business Acquisition [Line Items]
Weighted- average useful lives (Years)				10 years
Acquired IPR&D | Maximum | Salix
Business Acquisition [Line Items]
Fair value discount rate								10.00%
Acquired IPR&D | Minimum | Salix
Business Acquisition [Line Items]
Fair value discount rate								11.00%