CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) shares in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME [Abstract]
Total revenues	$ 1,038,460,000	$ 873,579,000	$ 2,564,896,000	$ 2,239,142,000
Cost of revenues	747,170,000	664,537,000	1,961,292,000	1,821,220,000
Gross profit	291,290,000	209,042,000	603,604,000	417,922,000
Selling, administrative and general expenses	71,390,000	66,074,000	207,350,000	199,808,000
Gain on sale of property, plant & equipment and businesses	799,000	1,002,000	7,423,000	238,527,000
Restructuring charges	(448,000)	(750,000)	(4,546,000)	(750,000)
Other operating expense, net	(8,045,000)	(2,889,000)	(22,391,000)	(17,645,000)
Operating earnings	212,206,000	140,331,000	376,740,000	438,246,000
Other nonoperating income (expense), net	(2,818,000)	(593,000)	(2,277,000)	4,030,000
Interest expense, net	37,800,000	40,891,000	183,931,000	201,531,000
Earnings from continuing operations before income taxes	171,588,000	98,847,000	190,532,000	240,745,000
Provision for income taxes	45,386,000	31,066,000	51,177,000	71,947,000
Earnings from continuing operations	126,202,000	67,781,000	139,355,000	168,798,000
Loss on discontinued operations, net of tax	(2,397,000)	(842,000)	(7,066,000)	(1,896,000)
Net earnings	123,805,000	66,939,000	132,289,000	166,902,000
Other comprehensive income, net of tax
Reclassification adjustment for cash flow hedges	282,000	598,000	5,607,000	4,167,000
Adjustment for funded status of benefit plans	0	0	0	2,943,000
Amortization of actuarial loss and prior service cost for benefit plans	3,883,000	1,114,000	9,261,000	1,006,000
Other comprehensive income	4,165,000	1,712,000	14,868,000	8,116,000
Comprehensive income	$ 127,970,000	$ 68,651,000	$ 147,157,000	$ 175,018,000
Basic earnings (loss) per share
Continuing operations	$ 0.95	$ 0.51	$ 1.05	$ 1.29
Discontinued operations	(0.02)	0.00	(0.06)	(0.02)
Net earnings	0.93	0.51	0.99	1.27
Diluted earnings (loss) per share
Continuing operations	0.93	0.51	1.03	1.27
Discontinued operations	(0.02)	(0.01)	(0.05)	(0.01)
Net earnings (loss)	$ 0.91	$ 0.50	$ 0.98	$ 1.26
Weighted-average common shares outstanding
Basic	133,474	131,797	133,082	131,256
Assuming dilution	135,558	133,369	134,942	132,759
Cash dividends per share of common stock	$ 0.10	$ 0.06	$ 0.30	$ 0.16
Depreciation, depletion, accretion and amortization	$ 69,662,000	$ 71,157,000	$ 204,770,000	$ 208,858,000
Effective tax rate from continuing operations	26.50%	31.40%	26.90%	29.90%