SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)	9 Months Ended
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)	Sep. 30, 2015
Accounting Policies [Abstract]
Basis of Presentation	The interim unaudited consolidated financial statements reflect all adjustments which in the opinion of management are necessary for a fair statement of results of operations, comprehensive income, financial condition, cash flows and stockholders' equity for the periods presented. Except as otherwise disclosed, all such adjustments are of a normal recurring nature. Operating results for the interim periods are not necessarily indicative of the results that may be expected for the full year. These interim unaudited consolidated financial statements should be read in conjunction with the audited consolidated financial statements included in the Company’s 2014 Annual Report on Form 10-K. The year-end balance sheet data was derived from the audited financial statements as of December 31, 2014, but does not include all the disclosures required by accounting principles generally accepted in the United States (“GAAP”).
Reclassifications	Prior to the Company's clinical trials central laboratory services joint venture, Q² Solutions, the earnings of the Company's equity method investees consisted of earnings that were not directly taxable to the investees, in which case it was appropriate to present equity in earnings of equity method investees before income tax expense on the consolidated statements of operations. The earnings of Q² Solutions, which closed on July 1, 2015, includes earnings that are directly taxable to the joint venture. As a result of the Q² Solutions transaction, the current period presentation of equity in earnings of equity method investees is required to be presented below income tax expense on the consolidated statements of operations. The Company's equity in earnings of equity method investees on the consolidated statements of operations for the three and nine months ended September 30, 2014 have been reclassified to conform with the current period presentation. In addition as a result of the current period presentation of investment in equity method investees on the consolidated balance sheet, the Company's investment in equity method investees as of December 31, 2014 has been reclassified to conform with the current period presentation. For further details regarding the Company's investment in Q² Solutions, see Note 6. As a result of the classification of certain non-core assets as held for sale on the consolidated balance sheet in the current period, current assets held for sale on the consolidated balance sheet at December 31, 2014 were reclassified to conform with the current period presentation. For further details regarding assets held for sale, see Note 6. As a result of the early adoption of the accounting standard update (“ASU”) associated with classification of debt issuance costs, certain reclassifications have been made to the prior period financial statements to conform with the current period presentation. For further details regarding the impact of the ASU, see Adoption of New Accounting Standards.
Use Of Estimates	The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates.
Earnings Per Share	The Company's unvested restricted stock units that contain non-forfeitable rights to dividends are participating securities and, therefore, are included in the earnings allocation in computing earnings per share using the two-class method. Basic earnings per common share is calculated by dividing net income, adjusted for earnings allocated to participating securities, by the weighted average number of common shares outstanding. Diluted earnings per common share is calculated by dividing net income, adjusted for earnings allocated to participating securities, by the weighted average number of common shares outstanding after giving effect to all potentially dilutive common shares outstanding during the period. Potentially dilutive common shares include the dilutive effect of outstanding stock options and performance share units granted under the Company's Amended and Restated Employee Long-Term Incentive Plan and its Amended and Restated Non-Employee Director Long-Term Incentive Plan. Earnings allocable to participating securities include the portion of dividends declared as well as the portion of undistributed earnings during the period allocable to participating securities.
New Accounting Standards	Adoption of New Accounting Standards On January 1, 2015, the Company adopted a new accounting standard issued by the Financial Accounting Standards Board ("FASB") related to the presentation and reporting of discontinued operations, including the disposals of components of an entity. The standard changes the criteria for reporting discontinued operations and requires expanded disclosures about discontinued operations that will provide financial statement users with more information about the assets, liabilities, income, and expenses of discontinued operations. The new standard also requires disclosure of the pre-tax income attributable to a disposal of a significant part of an organization that does not qualify for discontinued operations reporting. The impact of this standard on the Company’s results of operations, financial position, cash flows and disclosures will be assessed as part of any future disposal activity. In April 2015, the FASB issued an ASU which requires that debt issuance costs be presented in the balance sheet as a direct reduction to the carrying amount of the associated debt liability, consistent with debt discounts. The Company adopted this standard in the second quarter of 2015 and applied the standard retrospectively. Adoption of this standard has resulted in the reclassification of $20 million of unamortized debt issuance costs from other assets to a reduction of long-term debt on the consolidated balance sheet at December 31, 2014. New Accounting Pronouncements In May 2014, the FASB issued an ASU on revenue recognition. This ASU outlines a single comprehensive model to use in accounting for revenue arising from contracts with customers. This standard supersedes existing revenue recognition requirements and eliminates most industry-specific guidance from GAAP. The core principle of the revenue recognition standard is to require an entity to recognize as revenue the amount that reflects the consideration to which it expects to be entitled in exchange for goods or services as it transfers control to its customers. The standard requires additional disclosures including those that are qualitative and quantitative disclosures about the nature, amount, timing and uncertainty of revenue and cash flows arising from contracts with customers. In August 2015, the FASB deferred the effective date of this ASU to the first quarter of 2018, with early adoption permitted beginning in the first quarter of 2017. The ASU can be applied using a full retrospective method or a modified retrospective method of adoption. The Company is currently assessing the impact of the adoption of this ASU on the Company’s results of operations, financial position and cash flows. In February 2015, the FASB issued an ASU which makes targeted amendments to the current consolidation guidance for variable interest entities and limited partnerships and similar entities. The ASU is effective for the Company in the first quarter of 2016 with the option of using a full retrospective or a modified retrospective method. The Company does not expect the adoption of this standard to have a material impact on its results of operations, financial position and cash flows. In April 2015, the FASB issued an ASU which provides guidance in determining whether a cloud computing arrangement includes a software license. If it is determined that a cloud computing arrangement does include a software license, the software element of the arrangement should be accounted for consistent with the acquisition of other software licenses. If the arrangement does not include a software license, it should be accounted for as a service contract. The ASU is effective for the Company in the first quarter of 2016 and can be applied prospectively to all arrangements entered into or materially modified after the effective date or retrospectively. The Company does not expect the adoption of this ASU to have a material impact on its results of operations, financial position and cash flows. In September 2015, the FASB issued an ASU which requires that an acquirer recognize adjustments to provisional amounts in a business combination that are identified during the measurement period in the reporting period in which the adjustment amounts are determined, including the cumulative effect of the change in provisional amount as if the accounting had been completed at the acquisition date. The ASU is effective for the Company in the first quarter of 2016 with early adoption permitted and will be applied prospectively to adjustments to provisional amounts after the effective date. The Company does not expect the adoption of this ASU to have a material impact on its results of operations, financial position and cash flows.
Derivative Financial Instruments	The Company uses derivative financial instruments to manage its exposure to market risks for changes in interest rates and, from time to time, foreign currencies. This strategy includes the use of interest rate swap agreements, forward starting interest rate swap agreements, treasury lock agreements and foreign currency forward contracts to manage its exposure to movements in interest and currency rates. The Company has established policies and procedures for risk assessment and the approval, reporting and monitoring of derivative financial instrument activities. These policies prohibit holding or issuing derivative financial instruments for speculative purposes. The Company does not enter into derivative financial instruments that contain credit-risk-related contingent features or requirements to post collateral.
Interest Rate Risk	The Company is exposed to interest rate risk on its cash and cash equivalents and its debt obligations. Interest income earned on cash and cash equivalents may fluctuate as interest rates change; however, due to their relatively short maturities, the Company does not hedge these assets or their investment cash flows and the impact of interest rate risk is not material. The Company's debt obligations consist of fixed-rate and variable-rate debt instruments. The Company's primary objective is to achieve the lowest overall cost of funding while managing the variability in cash outflows within an acceptable range. In order to achieve this objective, the Company has entered into interest rate swaps. Interest rate swaps involve the periodic exchange of payments without the exchange of underlying principal or notional amounts. Net settlements between the counterparties are recognized as an adjustment to interest expense, net.