SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	3 Months Ended
Mar. 31, 2018
Text Block [Abstract]
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	NOTE 2. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES The Company adopted the New Revenue Accounting Standard on January 1, 2018 using the modified retrospective transition method. Below are the Company’s revised accounting policies reflecting the provisions of the New Revenue Accounting Standard and ASU 2016-01 (as codified under ASC Topic 321) further discussed in Note 1. All other significant accounting policies described in the Form 10-K for the year ended December 31, 2017 remain unchanged. Also refer to Note 3 of the condensed consolidated financial statements for certain quantitative disclosures relating to the Company’s revenue from contracts with customers. Revenue Recognition and Costs to Obtain or Fulfill a Contract with a Customer Revenue recognition: Revenue is recognized when control of promised goods or services is transferred to the customer, in an amount that reflects the consideration the Company expects to be entitled to in exchange for those goods or services. When contracts with customers contain multiple performance obligations, the Company accounts for individual performance obligations separately if they are distinct. The transaction price is allocated to each distinct performance obligation on a relative SSP basis. The Company determines the SSP by using the price charged for a deliverable when sold separately or uses management’s best estimate of SSP for goods or services not sold separately based on the maximum number of observable data points, including: internal factors relevant to its pricing practices such as costs and margin objectives; standalone sales prices of similar products; percentage of the fee charged for a primary product or service relative to a related product or service; and customer segment and geography. Additional consideration is also given to market conditions such as competitor pricing strategies and market trends. Sales, usage-based, value added and other taxes are excluded from revenues. MIS Revenue In the MIS segment, revenue arrangements are generally comprised of two distinct performance obligations, an initial rating and the related monitoring service. Revenue attributed to initial ratings of issued securities is generally recognized when the rating is delivered to the issuer. Revenue attributed to monitoring of issuers or issued securities is recognized ratably over the period in which the monitoring is performed, generally one year. In the case of certain structured finance products, primarily CMBS, issuers can elect to pay all of the annual monitoring fees upfront. These fees are deferred and recognized over the future monitoring periods based on the expected lives of the rated securities. MIS arrangements generally have standard contractual terms for which the stated payments are due at conclusion of the ratings process for initial ratings and either upfront or in arrears for monitoring services; and are signed by customers either on a per issue basis or at the beginning of the relationship with the customer. However, customer fee arrangements may be adjusted for which the Company accounts for as variable consideration at inception, which is constrained based on the Company’s assessment of the realization of the adjustment amount. The Company allocates the transaction price within arrangements that include both the initial rating and the related monitoring service based upon the relative SSP of each service. The Company generally uses management’s best estimate based on observable pricing points in determining SSP for its initial ratings as the Company rarely provides initial ratings separately without providing related monitoring services. The SSP for monitoring fees in these arrangements are generally based upon directly observable selling prices where the monitoring service is sold separately. MA Revenue In the MA segment, products and services offered by the Company include hosted research and data subscriptions, installed software subscriptions, perpetual installed software licenses and related maintenance, or PCS, and professional services. Subscription and PCS contracts are generally invoiced in advance of the contractual coverage period, which is principally one year, but can range from 3-5 years; while perpetual software licenses are generally invoiced upon delivery and professional services are invoiced as those services are provided. Payment terms and conditions vary by contract type, but primarily include a requirement of payment within 30 to 60 days. Revenue from research, data and other hosted subscriptions is recognized ratably over the related subscription period. A large portion of these services are invoiced in the months of November, December and January. Revenue from the sale of a software license, when considered distinct from the related software implementation services, is generally recognized at the time the product master or first copy is delivered or transferred to the customer. However, in instances where the software license (perpetual or subscription) and related implementation services are considered to be one combined performance obligation, revenue is recognized on a percentage-of-completion basis (input method) as implementation services are performed over time, which is consistent with the pattern of recognition for the software implementation services if considered to be a separate distinct performance obligation. The Company exercises judgment in determining the level of integration and interdependency between the promise to grant the software license and the promise to deliver the related implementation services. This determination influences whether the software license is considered distinct and accounted for separately, or not distinct and accounted for together with the implementation services and recognized over time. PCS is generally recognized ratably over the contractual period commencing when the software license is fully delivered. Revenue from installed software subscriptions, which includes PCS, is bifurcated into a software license performance obligation and a PCS performance obligation, which follow the patterns of recognition described above. For implementation services and other service projects within the ERS and ESA LOBs for which fees are fixed, the Company determined progress towards completion is most accurately measured on a percentage-of-completion basis (input method) as this approach utilizes the most directly observable data points and is therefore used to recognize the related revenue. For implementation services where price varies based on time expended, a time-based measure of progress towards completion of the performance obligation is utilized. Revenue from professional services rendered within the PS LOB is generally recognized as the services are performed. Products and services offered within the MA segment are sold either stand-alone or together in various combinations. In instances where an arrangement contains multiple performance obligations, the Company accounts for the individual performance obligations separately if they are considered distinct. Revenue is generally allocated to all performance obligations based upon the relative SSP at contract inception. Judgment is often required to determine the SSP for each distinct performance obligation. Revenue is recognized for each performance obligation based upon the conditions for revenue recognition noted above. In the MA segment, customers usually pay a fixed fee for the products and services based on signed contracts. However, accounting for variable consideration is applied mainly for: i) estimates for cancellation rights and price concessions and ii) T&M based services. The Company estimates the variable consideration associated with cancellation rights and price concessions based on the expected amount to be provided to customers and reduces the amount of revenue to be recognized. T&M based contracts represent about half of MA’s service projects within the ERS and ESA LOBs. The Company provides agreed upon services at a contracted daily or hourly rate. The commitment represents a series of goods and services that are substantially the same and have the same pattern of transfer to the customer. As such, if T&M services are sold with other MA products, the Company allocates the variable consideration entirely to the T&M performance obligation if the services are sold at standard pricing or at a similar discount level compared to other performance obligations in the same revenue contract. If these criteria are not met, the Company estimates variable consideration for each performance obligation upfront. Each form of variable consideration is included in the transaction price only to the extent that it is probable that a significant reversal of any incremental revenue will not occur. Costs to Obtain or Fulfill a Contract with a Customer: Costs incurred to obtain customer contracts, such as sales commissions, are deferred and recorded within other current assets and other assets when such costs are determined to be incremental to obtaining a contract, would not have been incurred otherwise and the Company expects to recover those costs. These costs are amortized to expense consistent with the recognition pattern of the related revenue. Depending on the line of business to which the contract relates, this may be based upon the average economic life of the products sold or average period for which services are provided, inclusive of anticipated contract renewals. Determining the estimated economic life of the products sold requires judgment with respect to anticipated future technological changes. The Company had a balance of $95.5 million in such deferred costs as of March 31, 2018 and recognized $8.6 million of related amortization during the three-month period ended March 31, 2018, which is included within SG&A expenses in the consolidated statement of operations. Costs incurred to obtain customer contracts are only in the MA segment. The Company also capitalizes work-in-process costs for in-progress MIS ratings, which is amortized consistent with the rendering of the related services to the customers. The Company had a balance of $10.2 million in such deferred costs as of March 31, 2018 and recognized $9.4 million of amortization of the costs deferred as of January 1, 2018 during the three-month period ended March 31, 2018, which is included within operating expenses in the consolidated statement of operations. In addition, within the MA segment, the Company capitalizes royalty costs related to third-party information data providers associated with hosted company information and business intelligence products. The Company had a balance of $32.4 million in such deferred costs as of March 31, 2018 and recognized $14.2 million of related amortization during the three-month period ended March 31, 2018, which is included within operating expenses in the consolidated statement of operations. Fair Value of Financial Instruments The Company’s financial instruments include cash, cash equivalents, trade receivables and payables, all of which are short-term in nature and, accordingly, approximate fair value. Additionally, the Company invests in certain short-term investments consisting primarily of certificates of deposit that are carried at cost, which approximates fair value due to their short-term maturities. The Company also has certain investments in closed-ended and open-ended mutual funds in India which are accounted for as equity securities with readily determinable fair values under ASC Topic 321. Beginning in the first quarter of 2018, the Company will measure these investments at fair value with both realized gains and losses and unrealized holding gains and losses for these investments included in net income. Prior to January 1, 2018, the investments in closed-ended and open-ended mutual funds in India were designated as ‘available for sale’ under Topic 320 of the ASC. Accordingly, unrealized gains and losses on these investments were recorded to other comprehensive income and were reclassified out of accumulated other comprehensive income to the statement of operations when the investment matured or was sold using a specific identification method. Also, the Company uses derivative instruments to manage certain financial exposures that occur in the normal course of business. These derivative instruments are carried at fair value on the Company’s consolidated balance sheets. Fair value is defined by the ASC as the price that would be received from selling an asset or paid to transfer a liability (i.e., an exit price) in an orderly transaction between market participants at the measurement date. The determination of this fair value is based on the principal or most advantageous market in which the Company could commence transactions and considers assumptions that market participants would use when pricing the asset or liability, such as inherent risk, transfer restrictions and risk of nonperformance. Also, determination of fair value assumes that market participants will consider the highest and best use of the asset. The ASC establishes a fair value hierarchy whereby the inputs contained in valuation techniques used to measure fair value are categorized into three broad levels as follows: Level 1: quoted market prices in active markets that the reporting entity has the ability to access at the date of the fair value measurement; Level 2: inputs other than quoted market prices described in Level 1 that are observable for the asset or liability, either directly or indirectly, such as quoted prices in active markets for similar assets or liabilities, quoted prices for identical or similar assets or liabilities in markets that are not active or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities; Level 3: unobservable inputs that are supported by little or no market activity and that are significant to the fair value measurement of the assets or liabilities.

NOTE 2. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

The Company adopted the New Revenue Accounting Standard on January 1, 2018 using the modified retrospective transition method. Below are the Company’s revised accounting policies reflecting the provisions of the New Revenue Accounting Standard and ASU 2016-01 (as codified under ASC Topic 321) further discussed in Note 1. All other significant accounting policies described in the Form 10-K for the year ended December 31, 2017 remain unchanged. Also refer to Note 3 of the condensed consolidated financial statements for certain quantitative disclosures relating to the Company’s revenue from contracts with customers.

Revenue Recognition and Costs to Obtain or Fulfill a Contract with a Customer

Revenue recognition:

Revenue is recognized when control of promised goods or services is transferred to the customer, in an amount that reflects the consideration the Company expects to be entitled to in exchange for those goods or services.

When contracts with customers contain multiple performance obligations, the Company accounts for individual performance obligations separately if they are distinct. The transaction price is allocated to each distinct performance obligation on a relative SSP basis. The Company determines the SSP by using the price charged for a deliverable when sold separately or uses management’s best estimate of SSP for goods or services not sold separately based on the maximum number of observable data points, including: internal factors relevant to its pricing practices such as costs and margin objectives; standalone sales prices of similar products; percentage of the fee charged for a primary product or service relative to a related product or service; and customer segment and geography. Additional consideration is also given to market conditions such as competitor pricing strategies and market trends.

Sales, usage-based, value added and other taxes are excluded from revenues.

MIS Revenue

In the MIS segment, revenue arrangements are generally comprised of two distinct performance obligations, an initial rating and the related monitoring service. Revenue attributed to initial ratings of issued securities is generally recognized when the rating is delivered to the issuer. Revenue attributed to monitoring of issuers or issued securities is recognized ratably over the period in which the monitoring is performed, generally one year. In the case of certain structured finance products, primarily CMBS, issuers can elect to pay all of the annual monitoring fees upfront. These fees are deferred and recognized over the future monitoring periods based on the expected lives of the rated securities.

MIS arrangements generally have standard contractual terms for which the stated payments are due at conclusion of the ratings process for initial ratings and either upfront or in arrears for monitoring services; and are signed by customers either on a per issue basis or at the beginning of the relationship with the customer. However, customer fee arrangements may be adjusted for which the Company accounts for as variable consideration at inception, which is constrained based on the Company’s assessment of the realization of the adjustment amount.

The Company allocates the transaction price within arrangements that include both the initial rating and the related monitoring service based upon the relative SSP of each service. The Company generally uses management’s best estimate based on observable pricing points in determining SSP for its initial ratings as the Company rarely provides initial ratings separately without providing related monitoring services. The SSP for monitoring fees in these arrangements are generally based upon directly observable selling prices where the monitoring service is sold separately.

MA Revenue

In the MA segment, products and services offered by the Company include hosted research and data subscriptions, installed software subscriptions, perpetual installed software licenses and related maintenance, or PCS, and professional services. Subscription and PCS contracts are generally invoiced in advance of the contractual coverage period, which is principally one year, but can range from 3-5 years; while perpetual software licenses are generally invoiced upon delivery and professional services are invoiced as those services are provided. Payment terms and conditions vary by contract type, but primarily include a requirement of payment within 30 to 60 days.

Revenue from research, data and other hosted subscriptions is recognized ratably over the related subscription period. A large portion of these services are invoiced in the months of November, December and January.

Revenue from the sale of a software license, when considered distinct from the related software implementation services, is generally recognized at the time the product master or first copy is delivered or transferred to the customer. However, in instances where the software license (perpetual or subscription) and related implementation services are considered to be one combined performance obligation, revenue is recognized on a percentage-of-completion basis (input method) as implementation services are performed over time, which is consistent with the pattern of recognition for the software implementation services if considered to be a separate distinct performance obligation. The Company exercises judgment in determining the level of integration and interdependency between the promise to grant the software license and the promise to deliver the related implementation services. This determination influences whether the software license is considered distinct and accounted for separately, or not distinct and accounted for together with the implementation services and recognized over time. PCS is generally recognized ratably over the contractual period commencing when the software license is fully delivered. Revenue from installed software subscriptions, which includes PCS, is bifurcated into a software license performance obligation and a PCS performance obligation, which follow the patterns of recognition described above.

For implementation services and other service projects within the ERS and ESA LOBs for which fees are fixed, the Company determined progress towards completion is most accurately measured on a percentage-of-completion basis (input method) as this approach utilizes the most directly observable data points and is therefore used to recognize the related revenue. For implementation services where price varies based on time expended, a time-based measure of progress towards completion of the performance obligation is utilized.

Revenue from professional services rendered within the PS LOB is generally recognized as the services are performed.

Products and services offered within the MA segment are sold either stand-alone or together in various combinations. In instances where an arrangement contains multiple performance obligations, the Company accounts for the individual performance obligations separately if they are considered distinct. Revenue is generally allocated to all performance obligations based upon the relative SSP at contract inception. Judgment is often required to determine the SSP for each distinct performance obligation. Revenue is recognized for each performance obligation based upon the conditions for revenue recognition noted above.

In the MA segment, customers usually pay a fixed fee for the products and services based on signed contracts. However, accounting for variable consideration is applied mainly for: i) estimates for cancellation rights and price concessions and ii) T&M based services.

The Company estimates the variable consideration associated with cancellation rights and price concessions based on the expected amount to be provided to customers and reduces the amount of revenue to be recognized. T&M based contracts represent about half of MA’s service projects within the ERS and ESA LOBs. The Company provides agreed upon services at a contracted daily or hourly rate. The commitment represents a series of goods and services that are substantially the same and have the same pattern of transfer to the customer. As such, if T&M services are sold with other MA products, the Company allocates the variable consideration entirely to the T&M performance obligation if the services are sold at standard pricing or at a similar discount level compared to other performance obligations in the same revenue contract. If these criteria are not met, the Company estimates variable consideration for each performance obligation upfront.

Each form of variable consideration is included in the transaction price only to the extent that it is probable that a significant reversal of any incremental revenue will not occur.

Costs to Obtain or Fulfill a Contract with a Customer:

Costs incurred to obtain customer contracts, such as sales commissions, are deferred and recorded within other current assets and other assets when such costs are determined to be incremental to obtaining a contract, would not have been incurred otherwise and the Company expects to recover those costs. These costs are amortized to expense consistent with the recognition pattern of the related revenue. Depending on the line of business to which the contract relates, this may be based upon the average economic life of the products sold or average period for which services are provided, inclusive of anticipated contract renewals. Determining the estimated economic life of the products sold requires judgment with respect to anticipated future technological changes. The Company had a balance of $95.5 million in such deferred costs as of March 31, 2018 and recognized $8.6 million of related amortization during the three-month period ended March 31, 2018, which is included within SG&A expenses in the consolidated statement of operations. Costs incurred to obtain customer contracts are only in the MA segment.

The Company also capitalizes work-in-process costs for in-progress MIS ratings, which is amortized consistent with the rendering of the related services to the customers. The Company had a balance of $10.2 million in such deferred costs as of March 31, 2018 and recognized $9.4 million of amortization of the costs deferred as of January 1, 2018 during the three-month period ended March 31, 2018, which is included within operating expenses in the consolidated statement of operations.

In addition, within the MA segment, the Company capitalizes royalty costs related to third-party information data providers associated with hosted company information and business intelligence products. The Company had a balance of $32.4 million in such deferred costs as of March 31, 2018 and recognized $14.2 million of related amortization during the three-month period ended March 31, 2018, which is included within operating expenses in the consolidated statement of operations.

Fair Value of Financial Instruments

The Company’s financial instruments include cash, cash equivalents, trade receivables and payables, all of which are short-term in nature and, accordingly, approximate fair value. Additionally, the Company invests in certain short-term investments consisting primarily of certificates of deposit that are carried at cost, which approximates fair value due to their short-term maturities.

The Company also has certain investments in closed-ended and open-ended mutual funds in India which are accounted for as equity securities with readily determinable fair values under ASC Topic 321. Beginning in the first quarter of 2018, the Company will measure these investments at fair value with both realized gains and losses and unrealized holding gains and losses for these investments included in net income.

Prior to January 1, 2018, the investments in closed-ended and open-ended mutual funds in India were designated as ‘available for sale’ under Topic 320 of the ASC. Accordingly, unrealized gains and losses on these investments were recorded to other comprehensive income and were reclassified out of accumulated other comprehensive income to the statement of operations when the investment matured or was sold using a specific identification method.

Also, the Company uses derivative instruments to manage certain financial exposures that occur in the normal course of business. These derivative instruments are carried at fair value on the Company’s consolidated balance sheets.

Fair value is defined by the ASC as the price that would be received from selling an asset or paid to transfer a liability (i.e., an exit price) in an orderly transaction between market participants at the measurement date. The determination of this fair value is based on the principal or most advantageous market in which the Company could commence transactions and considers assumptions that market participants would use when pricing the asset or liability, such as inherent risk, transfer restrictions and risk of nonperformance. Also, determination of fair value assumes that market participants will consider the highest and best use of the asset.

The ASC establishes a fair value hierarchy whereby the inputs contained in valuation techniques used to measure fair value are categorized into three broad levels as follows:

Level 1: quoted market prices in active markets that the reporting entity has the ability to access at the date of the fair value measurement;

Level 2: inputs other than quoted market prices described in Level 1 that are observable for the asset or liability, either directly or indirectly, such as quoted prices in active markets for similar assets or liabilities, quoted prices for identical or similar assets or liabilities in markets that are not active or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities;

Level 3: unobservable inputs that are supported by little or no market activity and that are significant to the fair value measurement of the assets or liabilities.