Business Segments (Tables)

3 Months Ended

Mar. 31, 2021

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 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 and are eliminated in consolidation.

	Three Months Ended
	March 31,
	2021			2020
	(Dollars in Millions)
Total revenues:
East Group	$	394.9		$	381.9
West Group		516.6			510.6
Total Building Materials business		911.5			892.5
Magnesia Specialties		70.9			65.7
Total	$	982.4		$	958.2
Products and services revenues:
East Group	$	372.5		$	357.9
West Group		484.1			473.2
Total Building Materials business		856.6			831.1
Magnesia Specialties		65.3			59.9
Total	$	921.9		$	891.0
Earnings (Loss) from operations:
East Group	$	61.7		$	34.8
West Group		31.9			22.7
Total Building Materials business		93.6			57.5
Magnesia Specialties		23.5			21.7
Corporate		(17.8	)		(21.4	)
Total	$	99.3		$	57.8