Marketable Securities (Tables)

6 Months Ended

Jun. 30, 2018

Investments Debt And Equity Securities [Abstract]

Schedule of Marketable Securities

	Market value		Cost basis		Unrealized losses, net
	(In millions)
December 31, 2017:
Current assets	$	3.0		3.0		—
Noncurrent assets:
The Amalgamated Sugar Company LLC	$	250.0		250.0		—
Other		5.7		5.9		(.2	)
Total	$	255.7		255.9		(.2	)
June 30, 2018:
Current assets	$	1.6		1.6		—
Noncurrent assets:
The Amalgamated Sugar Company LLC	$	250.0	$	250.0	$	—
Other		6.8		7.1		(.3	)
Total	$	256.8	$	257.1	$	(.3	)