Fair Value Measurements (Tables)

12 Months Ended

Dec. 31, 2020

Schedule of assets measured at fair value on a recurring basis

The table below summarizes the Company's assets which are measured at fair value on a recurring basis. The following fair value hierarchy is used to classify assets, based on inputs to valuation techniques utilized to measure fair value:

•Level 1 - Quoted prices in active markets for identical assets

•Level 2 - Significant other observable inputs, such as quoted market prices for similar instruments in active markets, quoted prices for identical or similar instruments in markets that are not active, or model-based valuations in which significant inputs used are observable

•Level 3 - Significant other unobservable inputs


			Fair Value Measurements at Reporting Date
As of December 31, 2020	Fair Value		Level 1		Level 2
Available-for-sale debt securities:
Corporate bonds	$	3,090.3	—		$	3,090.3
U.S. government and government agency obligations	128.9		—		128.9
Sovereign bonds	66.3		—		66.3
Commercial paper	276.1		—		276.1
Certificates of deposit	127.5		—		127.5
Equity securities (unrestricted)	48.3		$	48.3	—
Equity securities (restricted)	791.5		791.5		—
	$	4,528.9	$	839.8	$	3,689.1

As of December 31, 2019
Available-for-sale debt securities:
Corporate bonds	$	3,988.1	—		$	3,988.1
U.S. government and government agency obligations	54.4		—		54.4
Sovereign bonds	27.3		—		27.3
Commercial paper	92.3		—		92.3
Certificates of deposit	72.4		—		72.4
Equity securities (unrestricted)	61.6		$	61.6	—
Equity securities (restricted)	557.2		557.2		—
	$	4,853.3	$	618.8	$	4,234.5