REDEEMABLE NONCONTROLLING INTERESTS - CHANGE IN REDEEMABLE NONCONTROLLING INTEREST (Details) $ in Millions, ₨ in Billions	3 Months Ended	12 Months Ended
Mar. 31, 2020 USD ($)	Mar. 31, 2019 USD ($)	Dec. 31, 2019 INR (₨)	Dec. 31, 2019 USD ($)
Noncontrolling Interest [Abstract]
Balance as of January 1,	$ 1,096.5	$ 1,004.8		$ 1,004.8
Net income (loss) attributable to noncontrolling interests	7.7	(3.7)
Adjustment to noncontrolling interest redemption value	(6.3)	3.7
Purchase of redeemable noncontrolling interest	(524.4)	(425.7)	₨ (29.4)	(425.7)
Foreign currency translation adjustment attributable to noncontrolling interests	(32.1)	9.9
Balance as of March 31,	$ 541.4	$ 589.0		$ 1,096.5

Change in noncontrolling interest during the period as a result of a change in the redemption value of redeemable noncontrolling interest.

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Amount of Net Income (Loss) attributable to redeemable noncontrolling interest.

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The cash outflow during the period for redemption of redeemable noncontrolling interests.

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As of the reporting date, the aggregate carrying amount of all noncontrolling interests which are redeemable by the (parent) entity (1) at a fixed or determinable price on a fixed or determinable date, (2) at the option of the holder of the noncontrolling interest, or (3) upon occurrence of an event that is not solely within the control of the (parent) entity. This item includes noncontrolling interest holder's ownership (or holders' ownership) regardless of the type of equity interest (common, preferred, other) including all potential organizational (legal) forms of the investee entity.

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Adjustments to temporary equity resulting from foreign currency translation adjustments.

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