GOODWILL AND PURCHASED INTANGIBLE ASSETS - Future Amortization Expense (Details) $ in Thousands	Mar. 31, 2019 USD ($)
Goodwill and Intangible Assets Disclosure [Abstract]
Finite-Lived Intangible Assets, Amortization Expense, Next Twelve Months	$ 179,253
Finite-Lived Intangible Assets, Amortization Expense, Year Two	174,411
Finite-Lived Intangible Assets, Amortization Expense, Year Three	160,128
Finite-Lived Intangible Assets, Amortization Expense, Year Four	156,419
Finite-Lived Intangible Assets, Amortization Expense, Year Five	75,012
Finite-Lived Intangible Assets, Amortization Expense, after Year Five	50,103
Finite-Lived Intangible Assets, Net	$ 795,326