SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)	9 Months Ended
Sep. 30, 2019
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 2018 Annual Report on Form 10-K. The year-end balance sheet data was derived from the audited consolidated financial statements as of December 31, 2018, but does not include all the disclosures required by accounting principles generally accepted in the United States (“GAAP”).
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 Pronouncements	Adoption of New Accounting Standards On January 1, 2019, the Company adopted a new accounting standard issued by the Financial Accounting Standards Board ("FASB") on accounting for leases using the modified retrospective method. This new accounting standard requires a lessee to recognize an asset and liability for most leases on its balance sheet. The Company elected the optional transition method that allowed for a cumulative-effect adjustment to the opening balance of retained earnings recorded on January 1, 2019 and did not restate previously reported results in the comparative periods. The Company also elected the package of practical expedients, which among other things, allowed it to carry forward its historical lease classification. As a result of adoption of the new standard, the Company recorded operating lease assets and lease liabilities of approximately $500 million and $550 million, respectively as of January 1, 2019. The operating lease liability was determined based on the present value of the remaining minimum rental payments and the operating lease asset was determined based on the value of the lease liability, adjusted for the deferred rent balances of approximately $50 million, which were previously included in accounts payable and accrued expenses as well as other liabilities. Accounting for the Company's finance leases remains substantially unchanged. The adoption of the new standard did not materially impact the Company's consolidated results of operations or cash flows. In addition, the adoption of this new accounting standard resulted in increased qualitative and quantitative disclosures regarding the amount, timing, and uncertainty of cash flows arising from leases. For further details, see Note 9. On January 1, 2019, the Company adopted a new accounting standard issued by the FASB that includes the overnight index swap rate based on the Secured Overnight Financing Rate as an additional benchmark interest rate for hedge accounting purposes. Adoption of this new accounting standard applies prospectively to new or redesignated hedges entered into after the adoption date and, therefore, did not have an impact on the Company's existing interest rate swap agreements. New Accounting Standards To Be Adopted In August 2018, the FASB issued an Accounting Standard Update (“ASU”) that aligns the requirements for deferring implementation costs incurred in a cloud computing arrangement that is a service contract with the requirements for capitalizing implementation costs incurred to develop or obtain internal-use software. This ASU is effective for the Company in the first quarter of 2020 with early adoption permitted and can be applied either retrospectively or prospectively to all implementation costs incurred after the date 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 June 2016, the FASB issued an ASU that changes the impairment model for most financial instruments, including trade receivables, from an incurred loss method to a new forward-looking approach, based on expected losses. The estimate of expected credit losses will require entities to incorporate considerations of historical information, current information and reasonable and supportable forecasts. This ASU is effective for the Company in the first quarter of 2020 and must be adopted using a modified retrospective transition approach. 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.
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.

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)

9 Months Ended

Sep. 30, 2019

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 2018 Annual Report on Form 10-K. The year-end balance sheet data was derived from the audited consolidated financial statements as of December 31, 2018, but does not include all the disclosures required by accounting principles generally accepted in the United States (“GAAP”).

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 Pronouncements

Adoption of New Accounting Standards

On January 1, 2019, the Company adopted a new accounting standard issued by the Financial Accounting Standards Board ("FASB") on accounting for leases using the modified retrospective method. This new accounting standard requires a lessee to recognize an asset and liability for most leases on its balance sheet. The Company elected the optional transition method that allowed for a cumulative-effect adjustment to the opening balance of retained earnings recorded on January 1, 2019 and did not restate previously reported results in the comparative periods. The Company also elected the package of practical expedients, which among other things, allowed it to carry forward its historical lease classification.

As a result of adoption of the new standard, the Company recorded operating lease assets and lease liabilities of approximately $500 million and $550 million, respectively as of January 1, 2019. The operating lease liability was determined based on the present value of the remaining minimum rental payments and the operating lease asset was determined based on the value of the lease liability, adjusted for the deferred rent balances of approximately $50 million, which were previously included in accounts payable and accrued expenses as well as other liabilities. Accounting for the Company's finance leases remains substantially unchanged. The adoption of the new standard did not materially impact the Company's consolidated results of operations or cash flows.

In addition, the adoption of this new accounting standard resulted in increased qualitative and quantitative disclosures regarding the amount, timing, and uncertainty of cash flows arising from leases. For further details, see Note 9.

On January 1, 2019, the Company adopted a new accounting standard issued by the FASB that includes the overnight index swap rate based on the Secured Overnight Financing Rate as an additional benchmark interest rate for hedge accounting purposes. Adoption of this new accounting standard applies prospectively to new or redesignated hedges entered into after the adoption date and, therefore, did not have an impact on the Company's existing interest rate swap agreements.

New Accounting Standards To Be Adopted

In August 2018, the FASB issued an Accounting Standard Update (“ASU”) that aligns the requirements for deferring implementation costs incurred in a cloud computing arrangement that is a service contract with the requirements for capitalizing implementation costs incurred to develop or obtain internal-use software. This ASU is effective for the Company in the first quarter of 2020 with early adoption permitted and can be applied either retrospectively or prospectively to all implementation costs incurred after the date 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 June 2016, the FASB issued an ASU that changes the impairment model for most financial instruments, including trade receivables, from an incurred loss method to a new forward-looking approach, based on expected losses. The estimate of expected credit losses will require entities to incorporate considerations of historical information, current information and reasonable and supportable forecasts. This ASU is effective for the Company in the first quarter of 2020 and must be adopted using a modified retrospective transition approach. 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.

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.