MARKETABLE INVESTMENT SECURITIES

3 Months Ended

Mar. 31, 2024

Investments, Debt and Equity Securities [Abstract]

The amortized cost, gross unrealized holding gains, gross unrealized holding losses, and fair value for debt securities classified as available-for-sale securities by major security type and class of security at March 31, 2024 and December 31, 2023 were as follows:


(in millions)	Amortized cost		Gross unrealized holding gains		Gross unrealized holding losses		Estimated fair value
March 31, 2024
Cash and cash equivalents:
Cash	$	93.1	$	—	$	—	$	93.1
Cash equivalents	3.8		—		—		3.8
Total cash and cash equivalents	96.9		—		—		96.9
Available-for-sale:
Corporate bonds and notes	6.9		—		(0.1)		6.8
Municipal bonds	0.6		—		—		0.6
Federal agency issues	—		—		—		—

Total	$	104.4	$	—	$	(0.1)	$	104.3


(in millions)	Amortized cost		Gross unrealized holding gains		Gross unrealized holding losses		Estimated fair value
December 31, 2023
Cash and cash equivalents:
Cash	$	129.9	$	—	$	—	$	129.9
Cash equivalents	2.2		—		—		2.2
Total cash and cash equivalents	132.1		—		—		132.1
Available-for-sale:
Corporate bonds and notes	8.4		—		(0.1)		8.3
Municipal bonds	0.5		—		—		0.5


Total	$	141.0	$	—	$	(0.1)	$	140.9

Cash, cash equivalents, and maturities of debt securities classified as available-for-sale securities were as follows at March 31, 2024:


(in millions)	Amortized cost		Estimated fair value
Cash	$	93.1	$	93.1
Cash equivalents	3.8		3.8
Available-for-sale:
Due within one year	7.5		7.4


Total	$	104.4	$	104.3

The cost of a security sold, or amount reclassified out of accumulated other comprehensive income or loss into net loss, is determined based on the specific identification method. The Company does not intend to sell these available-for-sale debt securities, and it is not more likely than not that the Company will be required to sell these securities prior to recovery of their amortized cost basis. Additional information relating to fair value of marketable investment securities can be found in Note 4.