CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) shares in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME [Abstract]
Total revenues	$ 3,422,181,000	$ 2,994,169,000	$ 2,770,709,000
Cost of revenues	2,564,648,000	2,406,587,000	2,343,829,000
Gross profit	857,533,000	587,582,000	426,880,000
Selling, administrative and general expenses	286,844,000	272,288,000	259,427,000
Gain on sale of property, plant & equipment and businesses	9,927,000	244,222,000	39,250,000
Restructuring charges	(4,988,000)	(1,308,000)	(1,509,000)
Other operating expense, net	(25,850,000)	(20,070,000)	(14,790,000)
Operating earnings	549,778,000	538,138,000	190,404,000
Other nonoperating income (expense), net	(1,678,000)	3,107,000	7,538,000
Interest income	345,000	960,000	943,000
Interest expense	220,588,000	243,367,000	202,588,000
Earnings (loss) from continuing operations before income taxes	327,857,000	298,838,000	(3,703,000)
Provision for (benefit from) income taxes
Current	89,340,000	74,039,000	9,673,000
Deferred	5,603,000	17,653,000	(34,132,000)
Total provision for (benefit from) income taxes	94,943,000	91,692,000	(24,459,000)
Earnings from continuing operations	232,914,000	207,146,000	20,756,000
Earnings (loss) on discontinued operations, net of income taxes (Note 2)	(11,737,000)	(2,223,000)	3,626,000
Net earnings	221,177,000	204,923,000	24,382,000
Other comprehensive income (loss), net of tax
Reclassification adjustment for cash flow hedges	5,828,000	4,856,000	2,992,000
Adjustment for funded status of benefit plans	23,832,000	(69,051,000)	111,883,000
Amortization of actuarial loss and prior service cost for benefit plans	11,985,000	2,112,000	11,011,000
Other comprehensive income (loss)	41,645,000	(62,083,000)	125,886,000
Comprehensive income	$ 262,822,000	$ 142,840,000	$ 150,268,000
Basic earnings (loss) per share
Continuing operations	$ 1.75	$ 1.58	$ 0.16
Discontinued operations	(0.09)	(0.02)	0.03
Net earnings	1.66	1.56	0.19
Diluted earnings (loss) per share
Continuing operations	1.72	1.56	0.16
Discontinued operations	(0.08)	(0.02)	0.03
Net earnings	$ 1.64	$ 1.54	$ 0.19
Weighted-average common shares outstanding
Basic	133,210	131,461	130,272
Assuming dilution	135,093	132,991	131,467