ACCUMULATED OTHER COMPREHENSIVE INCOME (Details) - USD ($) $ in Thousands		Jun. 30, 2016	Dec. 31, 2015
Accumulated Other Comprehensive Income (Loss) [Line Items]
Stockholders' equity		$ 9,274,705	$ 8,795,469
Foreign currency translation adjustments, net of tax
Accumulated Other Comprehensive Income (Loss) [Line Items]
Stockholders' equity	[1]	(190,176)	(217,263)
Net unrealized gain on marketable securities, net of tax
Accumulated Other Comprehensive Income (Loss) [Line Items]
Stockholders' equity	[2]	325,618	462,115
Stockholders' equity, before tax		354,600	456,100
Stockholders' equity, before tax, taxable		115,800	(25,200)
Accumulated other comprehensive income
Accumulated Other Comprehensive Income (Loss) [Line Items]
Stockholders' equity		135,442	244,852
Net Investment Hedging [Member] | Foreign currency translation adjustments, net of tax | Euro Senior Notes [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Stockholders' equity		93,800	126,800
Stockholders' equity, before tax		153,300	220,500
Net Investment Hedging [Member] | Foreign currency translation adjustments, net of tax | Foreign Exchange Forward [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Stockholders' equity		(34,800)	(34,800)
Stockholders' equity, before tax		(52,600)	(52,600)
Tax and Customs Administration, Netherlands [Member] | Net unrealized gain on marketable securities, net of tax
Accumulated Other Comprehensive Income (Loss) [Line Items]
Stockholders' equity, before tax, tax-exempt		$ 238,700	$ 481,300

[1] Foreign currency translation adjustments, net of tax, include net losses from fair value adjustments of $34.8 million after tax ($52.6 million before tax) associated with derivatives designated as net investment hedges at both June 30, 2016 and December 31, 2015 (see Note 5).Foreign currency translation adjustments, net of tax, include foreign currency transaction gains of $93.8 million after tax ($153.3 million before tax) and $126.8 million after tax ($220.5 million before tax) associated with the Company's 2022 Notes, 2024 Notes and 2027 Notes at June 30, 2016 and December 31, 2015, respectively. The 2022 Notes, 2024 Notes and 2027 Notes are Euro-denominated debt and are designated as hedges of certain of the Company's Euro-denominated net assets (see Note 7). The remaining balance in foreign currency translation adjustments excludes income taxes as a result of the Company's intention to indefinitely reinvest the earnings of its international subsidiaries outside of the United States.

[2] The unrealized gains before tax at June 30, 2016 were $354.6 million, of which unrealized gains of $238.7 million were exempt from tax in the Netherlands and unrealized gains of $115.8 million were taxable. The unrealized gains before tax at December 31, 2015 were $456.1 million, of which unrealized gains of $481.3 million were exempt from tax in the Netherlands and unrealized losses of $25.2 million were taxable.