SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Summary of Significant Accounting Policies [Line Items]
Equity method investments carrying value	$ 473	$ 46
Share of equity earnings from investments in affiliates	$ 23	$ 26	$ 24
Percentage of total revenues generated by medicaid and medicare programs	17.00%	17.00%	18.00%
Purchase price discount ESPP	15.00%
Percentage of accounts receivable due from government payers	16.00%	14.00%
Percentage of receivables due from patients	17.00%	17.00%
Available-for-sale equity securities	$ 6	$ 9
Trading equity securities	49	49
Other investments	8	8
Total	63	66
Gross unrealized gains from available-for-sale equity securities	2
Trading equity securities gain or (loss)	0	3	$ 7
Unamortized debt issuance expense	25	20
Deferred tax liabilities, net, noncurrent	(157)	(204)
New Accounting Pronouncement, Early Adoption, Effect [Member]
Summary of Significant Accounting Policies [Line Items]
Unamortized debt issuance expense		$ 20
Deferred tax assets, net, current	168
Deferred tax assets, net, noncurrent	26
Deferred tax liabilities, net, noncurrent	$ 142
Minimum [Member]
Summary of Significant Accounting Policies [Line Items]
Equity method investment, ownership percentage	20.00%
Finite-lived intangible asset, useful life	5 years
Maximum [Member]
Summary of Significant Accounting Policies [Line Items]
Equity method investment, ownership percentage	49.00%
Finite-lived intangible asset, useful life	20 years
Building and Building Improvements [Member] | Maximum [Member]
Summary of Significant Accounting Policies [Line Items]
Property, plant and equipment, useful life	31 years 6 months
Laboratory Equipment and Furniture and Fixtures [Member] | Minimum [Member]
Summary of Significant Accounting Policies [Line Items]
Property, plant and equipment, useful life	3 years
Laboratory Equipment and Furniture and Fixtures [Member] | Maximum [Member]
Summary of Significant Accounting Policies [Line Items]
Property, plant and equipment, useful life	7 years
Internal Use Software [Member] | Minimum [Member]
Summary of Significant Accounting Policies [Line Items]
Property, plant and equipment, useful life	3 years
Internal Use Software [Member] | Maximum [Member]
Summary of Significant Accounting Policies [Line Items]
Property, plant and equipment, useful life	5 years