Financial Instruments (Tables)

3 Months Ended

Mar. 31, 2021

Fair Value Disclosures [Abstract]

Financial Instruments not Carried at Fair Value but which Require Fair Value Disclosure

The following table presents the financial instruments that are not carried at fair value but which require fair value disclosure:

	December 31, 2020				March 31, 2021
	Carrying amount		Fair value		Carrying amount		Fair value
	(In millions)
Cash, cash equivalents and restricted cash	$	362.0	$	362.0	$	379.9	$	379.9
Long-term debt - Fixed rate Senior Notes		485.7		499.9		465.0		478.1