Investments (Tables)

3 Months Ended

Mar. 31, 2020

Investments Debt And Equity Securities [Abstract]

Gross Unrealized Gains and (Losses) Aggregated by Investment Category

The following tables show the gross unrealized gains and (losses) aggregated by investment category for available-for-sale investments:

As of March 31, 2020:	Cost		Gross Unrealized Gains		Gross Unrealized (Losses)			Estimated Fair Value
Short-term investments:
Available-for-sale investments:
Time deposits and certificates of deposit	$	10.4	$	—	$	—		$	10.4
Bankers' acceptance drafts		2.4		—		—			2.4
Commercial paper		26.4		—		(0.2	)		26.2
U.S. treasury obligations		10.0		—		—			10.0
U.S. agency obligations		12.3		0.1		—			12.4
	$	61.5	$	0.1	$	(0.2	)	$	61.4

As of March 31, 2020:	Cost		Gross Unrealized Gains		Gross Unrealized (Losses)		Estimated Fair Value
Long-term investments:
Available-for-sale investments:
Group insurance contracts	$	5.4	$	0.6	$	—	$	6.0

As of December 31, 2019:	Cost		Gross Unrealized Gains		Gross Unrealized (Losses)			Estimated Fair Value
Short-term investments:
Available-for-sale investments:
Time deposits and certificates of deposit	$	13.1	$	—	$	—		$	13.1
Bankers' acceptance drafts		4.0		—		—			4.0
Commercial paper		61.5		—		(0.3	)		61.2
U.S. treasury obligations		5.0		—		—			5.0
U.S. agency obligations		26.1		—		—			26.1
	$	109.7	$	—	$	(0.3	)	$	109.4

As of December 31, 2019:	Cost		Gross Unrealized Gains		Gross Unrealized (Losses)		Estimated Fair Value
Long-term investments:
Available-for-sale investments:
Group insurance contracts	$	5.2	$	0.6	$	—	$	5.8