Revenue Recognition (Tables)

6 Months Ended

Jun. 30, 2019

Revenue From Contract With Customer [Abstract]

Schedule of Company's Total Revenues by Category for each Reportable Segment

The following table presents the Company’s total revenues by category for each reportable segment:

	Three Months Ended
	June 30, 2019
	Products and Services		Freight		Total
	(Dollars in Thousands)
Mid-America Group	$	382,717	$	32,610	$	415,327
Southeast Group		132,036		4,988		137,024
West Group		611,003		39,875		650,878
Total Building Materials Business		1,125,756		77,473		1,203,229
Magnesia Specialties		70,379		5,860		76,239
Total	$	1,196,135	$	83,333	$	1,279,468
	Three Months Ended
	June 30, 2018
	Products and Services		Freight		Total
	(Dollars in Thousands)
Mid-America Group	$	325,578	$	25,014	$	350,592
Southeast Group		109,082		3,881		112,963
West Group		625,960		39,926		665,886
Total Building Materials Business		1,060,620		68,821		1,129,441
Magnesia Specialties		68,157		4,805		72,962
Total	$	1,128,777	$	73,626	$	1,202,403

	Six Months Ended
	June 30, 2019
	Products and Services		Freight		Total
	(Dollars in Thousands)
Mid-America Group	$	613,025	$	51,115	$	664,140
Southeast Group		247,348		8,914		256,262
West Group		1,074,514		73,194		1,147,708
Total Building Materials Business		1,934,887		133,223		2,068,110
Magnesia Specialties		139,553		10,760		150,313
Total	$	2,074,440	$	143,983	$	2,218,423
	Six Months Ended
	June 30, 2018
	Products and Services		Freight		Total
	(Dollars in Thousands)
Mid-America Group	$	493,468	$	35,905	$	529,373
Southeast Group		186,646		6,556		193,202
West Group		1,068,943		70,665		1,139,608
Total Building Materials Business		1,749,057		113,126		1,862,183
Magnesia Specialties		133,025		9,199		142,224
Total	$	1,882,082	$	122,325	$	2,004,407

Summary of Information About the Company's Contract Balances

The following table presents information about the Company’s contract balances:

(Dollars in Thousands)	June 30, 2019		December 31, 2018
Costs in excess of billings	$	9,452	$	1,975
Billings in excess of costs	$	9,088	$	6,743