Business Segments (Tables)

6 Months Ended

Jun. 30, 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						Six Months Ended
	June 30,						June 30,
	2021			2020			2021			2020
	(Dollars in Millions)
Total revenues:
East Group	$	635.3		$	534.5		$	1,030.2		$	916.5
West Group		666.8			682.5			1,183.4			1,193.1
Total Building Materials business		1,302.1			1,217.0			2,213.6			2,109.6
Magnesia Specialties		75.8			53.6			146.7			119.3
Total	$	1,377.9		$	1,270.6		$	2,360.3		$	2,228.9
Products and services revenues:
East Group	$	596.5		$	499.7		$	969.1		$	857.6
West Group		628.8			640.9			1,112.9			1,114.1
Total Building Materials business		1,225.3			1,140.6			2,082.0			1,971.7
Magnesia Specialties		70.0			48.9			135.2			108.8
Total	$	1,295.3		$	1,189.5		$	2,217.2		$	2,080.5
Earnings (Loss) from operations:
East Group	$	197.8		$	169.9		$	259.5		$	204.7
West Group		101.8			133.2			133.6			155.9
Total Building Materials business		299.6			303.1			393.1			360.6
Magnesia Specialties		23.1			13.2			46.7			34.9
Corporate		(15.2	)		(9.9	)		(33.0	)		(31.3	)
Total	$	307.5		$	306.4		$	406.8		$	364.2

	June 30, 2021		December 31, 2020
Assets employed:	(Dollars in Millions)
East Group	$	5,110.4	$	4,342.5
West Group		5,395.9		5,355.5
Total Building Materials business		10,506.3		9,698.0
Magnesia Specialties		168.3		167.9
Corporate		548.5		714.9
Total	$	11,223.1	$	10,580.8