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The aggregate costs related to goods produced and sold and services rendered by an entity during the reporting period. This excludes costs incurred during the reporting period related to financial services rendered and other revenue generating activities.

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Number of segments reported by the entity. A reportable segment is a component of an entity for which there is an accounting requirement to report separate financial information on that component in the entity's financial statements.

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Amount, excluding tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value added and excise.

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The aggregate total costs related to selling a firm's product and services, as well as all other general and administrative expenses. Direct selling expenses (for example, credit, warranty, and advertising) are expenses that can be directly linked to the sale of specific products. Indirect selling expenses are expenses that cannot be directly linked to the sale of specific products, for example telephone expenses, Internet, and postal charges. General and administrative expenses include salaries of non-sales personnel, rent, utilities, communication, etc.

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BASIS OF PRESENTATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Narrative (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018 USD ($) Country	Sep. 30, 2017 USD ($)	Sep. 30, 2018 USD ($) segment Country	Sep. 30, 2017 USD ($)	Jan. 01, 2018 USD ($)	Dec. 31, 2017 USD ($)
Accounting Policies [Abstract]
Number of countries in which entity operates \| Country	31		31
Number of reportable segments \| segment			3
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Retained earnings	$ 1,994,003		$ 1,994,003			$ 1,597,897
Other noncurrent assets	365,144		365,144			207,297
Deferred income tax liabilities	516,357		516,357			$ 436,879
Revenues	857,670	$ 1,038,907	2,485,811	$ 2,920,910
Cost of service	265,013	493,883	781,943	1,418,969
Selling, general and administrative expenses	369,495	$ 372,553	1,133,799	$ 1,092,648
Difference between Revenue Guidance in Effect before and after Topic 606 \| Accounting Standards Update 2014-09
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Retained earnings					$ 51,000
Other noncurrent assets					64,600
Deferred income tax liabilities					$ 15,600
Revenues	291,300		825,500
Cost of service	273,600		774,500
Selling, general and administrative expenses	$ 17,700		$ 51,000