ACCUMULATED OTHER COMPREHENSIVE LOSS - Summary of Changes in Accumulated Other Comprehensive Loss by Component (Details) $ in Millions	6 Months Ended
	Jun. 30, 2016 USD ($)
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at the beginning of the period	$ 2,503.1
Balance at the end of the period	2,471.2
Foreign Currency Translation Adjustments
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at the beginning of the period	(181.5)
Other comprehensive gain (loss) before reclassifications	19.5
Amounts reclassified from accumulated other comprehensive loss	0.0
Deferred income tax benefit	1.4
Balance at the end of the period	(160.6)
Unrealized Gain (Loss) on Cash Flow Hedges
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at the beginning of the period	11.8
Other comprehensive gain (loss) before reclassifications	(20.5)
Amounts reclassified from accumulated other comprehensive loss	(14.3)
Deferred income tax benefit	14.0
Balance at the end of the period	(9.0)
Unrealized (Loss) Gain on Available-for-sale Investments
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at the beginning of the period	(1.5)
Other comprehensive gain (loss) before reclassifications	3.2
Amounts reclassified from accumulated other comprehensive loss	0.6
Deferred income tax benefit	0.0
Balance at the end of the period	2.3
Unrealized Pension Costs
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at the beginning of the period	(11.4)
Other comprehensive gain (loss) before reclassifications	0.0
Amounts reclassified from accumulated other comprehensive loss	0.0
Deferred income tax benefit	0.0
Balance at the end of the period	(11.4)
Total Accumulated Other Comprehensive Loss
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at the beginning of the period	(182.6)
Other comprehensive gain (loss) before reclassifications	2.2
Amounts reclassified from accumulated other comprehensive loss	(13.7)
Deferred income tax benefit	15.4
Balance at the end of the period	$ (178.7)