CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) shares in Thousands, $ in Thousands		3 Months Ended
		Mar. 31, 2021	Mar. 31, 2020
CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME [Abstract]
Total revenues	[1]	$ 1,068,344	$ 1,049,242
Cost of revenues		839,077	847,519
Gross profit		229,267	201,723
Selling, administrative and general expenses		88,593	86,430
Gain on sale of property, plant & equipment and businesses		117,165	999
Other operating expense, net		(8,326)	(3,991)
Operating earnings		249,513	112,301
Other nonoperating income (expense), net		5,913	(9,336)
Interest expense, net		33,118	30,773
Earnings from continuing operations before income taxes		222,308	72,192
Income tax expense		60,638	12,194
Earnings from continuing operations		161,670	59,998
Earnings (loss) on discontinued operations, net of tax		(1,056)	260
Net earnings		160,614	60,258
Other comprehensive income (loss), net of tax
Deferred loss on interest rate derivative		0	(14,680)
Amortization of prior interest rate derivative loss		356	794
Amortization of actuarial loss and prior service cost for benefit plans		1,235	1,695
Other comprehensive income (loss)		1,591	(12,191)
Comprehensive income		$ 162,205	$ 48,067
Basic earnings (loss) per share
Continuing operations		$ 1.22	$ 0.45
Discontinued operations		(0.01)	0.00
Net earnings		1.21	0.45
Diluted earnings (loss) per share
Continuing operations		1.21	0.45
Discontinued operations		(0.01)	0.00
Net earnings		$ 1.20	$ 0.45
Weighted-average common shares outstanding
Basic		132,749	132,567
Assuming dilution		133,415	133,259
Effective tax rate from continuing operations		27.30%	16.90%

[1] ¹ The geographic markets are defined by states/countries as follows: East market — Arkansas, Delaware, Illinois, Kentucky, Maryland, North Carolina, Pennsylvania, Tennessee, Virginia, and Washington D.C. Gulf Coast market — Alabama, Florida, Georgia, Louisiana, Mexico, Mississippi, Oklahoma, South Carolina and Texas West market — Arizona, California and New Mexico