BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Restricted Cash and Restricted Cash Equivalents) (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Cash flows from operating activities:
Prepaid expenses and other assets	$ (8,432)	$ 1,061	$ (2,391)
Net cash provided by operating activities	292,218	192,820	167,217
Cash flows from investing activities:
Decrease in restricted cash and time deposits, net	418	0	29,597
Acquisition of businesses, net of cash acquired	(74,268)	(6,810)	(5,500)
Net cash used in investing activities	(112,123)	(36,151)	(9,320)
Effect of exchange rate changes on cash, cash equivalents and restricted cash	(14,240)	11,776	(3,387)
Net increase in cash, cash equivalents and restricted cash	188,856	218,191	164,977
Cash, cash equivalents and restricted cash, beginning of period	582,585	362,025
Cash, cash equivalents and restricted cash, beginning of period	582,855	364,664	199,687
Cash, cash equivalents and restricted cash, end of period	770,560	582,585	362,025
Cash, cash equivalents and restricted cash, end of period	771,711	582,855	364,664
As Originally Reported
Cash flows from operating activities:
Prepaid expenses and other assets		3,605	(4,791)
Net cash provided by operating activities		195,364	164,817
Cash flows from investing activities:
Decrease in restricted cash and time deposits, net		8	29,595
Acquisition of businesses, net of cash acquired		(6,840)
Net cash used in investing activities		(36,173)	(9,322)
Effect of exchange rate changes on cash, cash equivalents, and restricted cash		11,623	(3,386)
Net increase in cash, cash equivalents and restricted cash		220,560	162,576
Cash, cash equivalents and restricted cash, beginning of period	582,585	362,025	199,449
Cash, cash equivalents and restricted cash, end of period		582,585	362,025
ASU 2016-18 \| Effect
Cash flows from operating activities:
Prepaid expenses and other assets		(2,544)	2,400
Net cash provided by operating activities		(2,544)	2,400
Cash flows from investing activities:
Decrease in restricted cash and time deposits, net		(8)	2
Acquisition of businesses, net of cash acquired		30
Net cash used in investing activities		22	2
Effect of exchange rate changes on cash, cash equivalents, and restricted cash		153	(1)
Net increase in cash, cash equivalents and restricted cash		(2,369)	2,401
Cash, cash equivalents and restricted cash, beginning of period	$ 270	2,639	238
Cash, cash equivalents and restricted cash, end of period		$ 270	$ 2,639

Amount of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. Excludes cash and cash equivalents within disposal group and discontinued operation.

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