INCOME TAXES (Effective Tax Rate Reconciliation) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Effective Income Tax Rate Reconciliation, Amount [Abstract]
Provision for income taxes at federal statutory rate									$ 52,452	$ 61,007	$ 44,263
Increase/ (decrease) in taxes resulting from:
Impact from U.S. Tax Act									(4,009)	74,632	0
Entity classification election deferred tax asset impact									(25,962)	0	0
GILTI and BEAT U.S. taxes									1,526	0	0
Excess tax benefits relating to stock-based compensation									(17,370)	(9,307)	0
Subsidiary withholding tax liability and related foreign tax credit									(4,850)
Subsidiary withholding tax liability and related foreign tax credit										4,850	0
Foreign tax expense and tax rate differential									(88)	(39,997)	(33,477)
Effect of permanent differences									2,724	3,205	5,042
State taxes, net of federal benefit									3,452	(116)	1,192
Change in valuation allowance									151	783	0
Stock-based compensation expense									652	6,908	9,535
Other									839	(420)	645
Total	$ 18,803	$ 369	$ 6,864	$ (16,519)	$ 82,951	$ 7,953	$ 5,687	$ 4,954	$ 9,517	$ 101,545	$ 27,200
Effective tax rate									3.80%	58.30%	21.50%
Net deferred tax assets resulting from the change in tax status of foreign subsidiaries	$ 25,962								$ 25,962
ASU 2016-09
Increase/ (decrease) in taxes resulting from:
Excess tax benefit									$ 17,370	$ 9,307