Business Segments (Tables)

3 Months Ended

Mar. 31, 2020

Segment Reporting [Abstract]

Financial Data for Continuing Operation for Company's Reportable Business Segments

The following table displays selected financial data for the Company’s reportable business segments. Total revenues, as presented on the consolidated statements of earnings and comprehensive earnings, exclude intersegment revenues which represent sales from one segment to another segment, which are eliminated. Prior-year segment information has been reclassified to conform to the reporting structure change described in Note 1.

	Three Months Ended
	March 31,
	2020			2019
	(Dollars in Millions)
Total revenues:
Mid-America Group	$	260.8		$	248.1
Southeast Group		121.1			119.2
West Group		510.6			497.6
Total Building Materials Business		892.5			864.9
Magnesia Specialties		65.7			74.1
Total	$	958.2		$	939.0
Products and services revenues:
Mid-America Group	$	241.0		$	229.6
Southeast Group		116.9			115.3
West Group		473.2			464.2
Total Building Materials Business		831.1			809.1
Magnesia Specialties		59.9			69.2
Total	$	891.0		$	878.3
Earnings (Loss) from operations:
Mid-America Group	$	20.8		$	30.6
Southeast Group		14.0			21.1
West Group		22.7			20.3
Total Building Materials Business		57.5			72.0
Magnesia Specialties		21.7			22.6
Corporate		(21.4	)		(25.4	)
Total	$	57.8		$	69.2