Other Assets (Tables)

9 Months Ended

Sep. 30, 2021

Deferred Costs Capitalized Prepaid And Other Assets Disclosure [Abstract]

Other Assets

	December 31,		September 30,
	2020		2021
	(In millions)
Other noncurrent assets:
Land held for development	$	96.0	$	59.7
Operating lease right-of-use assets		26.1		21.8
Restricted cash and cash equivalents		37.8		37.6
IBNR receivables		37.1		32.6
Marketable securities		2.9		3.5
Pension asset		8.4		10.0
Note receivables - OPA		25.3		29.0
Other		8.7		13.5
Total	$	242.3	$	207.7