INVESTMENTS (Tables)

12 Months Ended

Dec. 31, 2019

Investments, Debt and Equity Securities [Abstract]

Schedule of Investments in Debt Securities

Investments in debt securities at the end of each period were as follows (in millions):



	December 31, 2019									December 31, 2018
Held-to-maturity	Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value		Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
Bank time deposits	$	100.2	$	—	$	—		$	100.2	$	20.0	$	—	$	—		$	20.0

Available-for-sale
Bank time deposits	$	13.1	$	—	$	—		$	13.1	$	—	$	—	$	—		$	—
Commercial paper	34.3		—		—			34.3		56.7		—		—			56.7
U.S. government and agency securities	113.2		0.6		—			113.8		79.7		0.2		(0.7		)	79.2
Foreign government bonds	1.7		—		—			1.7		1.7		—		—			1.7
Asset-backed securities	141.2		0.6		(0.1		)	141.7		110.6		0.1		(0.5		)	110.2
Corporate debt securities	487.0		2.3		(0.1		)	489.2		459.8		0.1		(4.3		)	455.6
Municipal securities	—		—		—			—		2.8		—		—			2.8
	$	790.5	$	3.5	$	(0.2	)	$	793.8	$	711.3	$	0.4	$	(5.5	)	$	706.2

Schedule of Cost and Fair Value of Investments in Debt Securities, by Contractual Maturity

The cost and fair value of investments in debt securities, by contractual maturity, as of December 31, 2019 were as follows:



	Held-to-Maturity				Available-for-Sale
	Cost		Fair Value		Cost		Fair Value
	(in millions)
Due in 1 year or less	$	100.2	$	100.2	$	237.2	$	237.6
Due after 1 year through 5 years	—		—		439.1		441.7
Instruments not due at a single maturity date	—		—		114.2		114.5
	$	100.2	$	100.2	$	790.5	$	793.8

Gross Unrealized Losses and Fair Values for Investments in Unrealized Loss Position

The following tables present gross unrealized losses and fair values for those investments that were in an unrealized loss position as of December 31, 2019 and 2018, aggregated by investment category and the length of time that individual securities have been in a continuous loss position (in millions):



	December 31, 2019
	Less than 12 Months					12 Months or Greater				Total
	Fair Value		Gross Unrealized Losses			Fair Value		Gross Unrealized Losses		Fair Value		Gross Unrealized Losses
Asset-backed securities	73.4		(0.1		)	—		—		73.4		(0.1		)
Corporate debt securities	81.4		(0.1		)	—		—		81.4		(0.1		)
	$	154.8	$	(0.2	)	$	—	$	—	$	154.8	$	(0.2	)



	December 31, 2018
	Less than 12 Months					12 Months or Greater					Total
	Fair Value		Gross Unrealized Losses			Fair Value		Gross Unrealized Losses			Fair Value		Gross Unrealized Losses
U.S. government and agency securities	$	0.7	$	(0.1	)	$	56.5	$	(0.6	)	$	57.2	$	(0.7	)
Asset-backed securities	4.0		—			61.3		(0.5		)	65.3		(0.5		)
Corporate debt securities	177.4		(1.1		)	203.7		(3.2		)	381.1		(4.3		)
	$	182.1	$	(1.2	)	$	321.5	$	(4.3	)	$	503.6	$	(5.5	)

Schedule of Investments in Unconsolidated Affiliates

Investments in these unconsolidated affiliates are recorded in "Long-term Investments" on the consolidated balance sheets, and are as follows:



	December 31,
	2019			2018
	(in millions)
Equity method investments
Cost	$	10.7		$	9.1
Equity in losses	(4.5		)	(4.7		)
Carrying value of equity method investments	6.2			4.4
Equity securities
Carrying value of non-marketable equity securities	23.1			18.1
Total investments in unconsolidated affiliates	$	29.3		$	22.5