Marketable securities (Tables)

3 Months Ended

Mar. 31, 2025

Marketable securities

Schedule of Marketable Securities

			Cost or
			amortized		Unrealized
	Market value		cost		loss, net
	(In millions)
December 31, 2024:
Current assets	$	1.9	$	1.9	$	—
Noncurrent assets	$	5.7	$	5.7	$	—
March 31, 2025:
Current assets	$	1.9	$	1.9	$	—
Noncurrent assets	$	5.2	$	5.2	$	—