DISCONTINUED OPERATIONS AND OTHER BUSINESS DISPOSITIONS (Details) $ in Thousands	3 Months Ended								12 Months Ended			17 Months Ended
	Dec. 31, 2019 USD ($) numberofcountries	Sep. 30, 2019 USD ($)	Jun. 30, 2019 USD ($)	Mar. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Sep. 30, 2018 USD ($)	Jun. 30, 2018 USD ($)	Mar. 31, 2018 USD ($)	Dec. 31, 2019 USD ($) numberofcountries	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Mar. 31, 2018 numberofcountries	Dec. 31, 2016
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of Countries in which Entity Operates | numberofcountries	15								15
Number of Countries Exited in connection with Discontinued Operations | numberofcountries												12
Percentage of controlling stake													83.00%
Disposal Group, Including Discontinued Operation, Additional Disclosures [Abstract]
Less: transaction costs									$ (700)
Less: Indemnification liabilities	$ 3,200								3,200
Disposal Group, Including Discontinued Operation, Income Statement Disclosures [Abstract]
Revenues									2,218,915	$ 2,636,746	$ 2,843,877
Total cost of revenue									(1,032,786)	(1,316,145)	(1,510,016)
Marketing expense									(339,355)	(395,737)	(400,918)
Selling, general and administrative expense									806,945	870,961	901,829
Restructuring									(31)	136	(18,828)
Other income, net									(53,329)	(53,008)	6,710
Provision for income taxes									0	0	0
Income (loss) from discontinued operations, net of tax	$ 435	$ 0	$ 0	$ 2,162	$ 0	$ 0	$ 0	$ 0	2,597	0	(1,974)
Service
Disposal Group, Including Discontinued Operation, Income Statement Disclosures [Abstract]
Revenues									1,126,357	1,205,487	1,266,452
Total cost of revenue									(114,462)	(120,077)	(160,810)
Product
Disposal Group, Including Discontinued Operation, Income Statement Disclosures [Abstract]
Revenues									1,092,558	1,431,259	1,577,425
Total cost of revenue									(918,324)	$ (1,196,068)	(1,349,206)
Discontinued Operations, Disposed of by Sale
Disposal Group, Including Discontinued Operation, Additional Disclosures [Abstract]
Fair value of minority investments retained or acquired											2,021
Cash proceeds received											3,462
Cash proceeds receivable											2,000
Less: transaction costs											(1,394)
Total net consideration received											6,089
Cumulative translation gain reclassified to earnings											14,718
Less: Net book value upon closing of the transactions											14,958
Less: Indemnification liabilities											5,365
Less: Unfavorable contract liability for transition services											2,114
Loss on dispositions									0		(1,630)
Disposal Group, Including Discontinued Operation, Income Statement Disclosures [Abstract]
Marketing expense									0		(1,239)
Selling, general and administrative expense									2,597		12,007
Restructuring									0		(778)
Other income, net									0		3,852
Income (loss) from discontinued operations before loss on dispositions and provision for income taxes									2,597		(263)
Provision for income taxes									0		(81)
Discontinued Operations, Disposed of by Sale | Service
Disposal Group, Including Discontinued Operation, Income Statement Disclosures [Abstract]
Revenues									0		12,602
Total cost of revenue									0		(2,557)
Discontinued Operations, Disposed of by Sale | Product
Disposal Group, Including Discontinued Operation, Income Statement Disclosures [Abstract]
Revenues									0		2,962
Total cost of revenue									$ 0		$ (3,098)