CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011
CASH PROVIDED BY (USED IN) OPERATIONS:
Net income	$ 126,531	$ 691,740
Adjustments to reconcile net income to net cash provided by operations:
Depreciation and amortization	183,323	150,236
Deferred income taxes	(5,068)	(30,880)
Provision for pension and postretirement benefits	27,813	12,059
Stock-based compensation expense	20,108	14,264
Gain on disposals of property, plant and equipment	(2,678)	(3,932)
Gain on sale of manufacturing operations	0	(662,448)
Gain on sale of land drilling operations	0	(214,803)
Postretirement benefit claims paid	(3,050)	(2,188)
Contributions to pension plans	(41,761)	(53,169)
Asset impairment charges	2,896	0
Write-off of deferred debt issuance costs	690	0
Changes in current assets and liabilities:
Receivables - trade and other	(115,873)	(41,570)
Inventories	0	(104,468)
Prepaid expenses and other current assets	(20,029)	(3,538)
Accounts payable	(1,115)	60,785
Accrued income taxes	(2,259)	212,352
Deferred revenues	(245)	44,929
Billings in excess of costs and estimated profits on uncompleted contracts	0	29,493
Other current liabilities	10,349	(7,449)
Net changes in other noncurrent assets and liabilities	9,870	36,596
Net cash provided by operations	189,502	128,009
CASH PROVIDED BY (USED IN) INVESTING ACTIVITIES:
Capital expenditures	(566,089)	(1,155,108)
Proceeds from sale of manufacturing operations	0	1,050,720
Proceeds from sale of land drilling operations, net	0	509,818
(Increase) decrease in restricted cash	0	15,265
Proceeds from disposals of property, plant and equipment	10,553	5,478
Net cash provided by (used in) investing activities	(555,536)	426,173
CASH PROVIDED BY (USED IN) FINANCING ACTIVITIES:
Proceeds from borrowings	493,415	0
Debt issue costs	(799)	0
Repayments of borrowings	(238,453)	(38,412)
Payments to acquire treasury stock	0	(80,924)
Excess tax benefits from share-based compensation	1,153	5,128
Proceeds from stock options	155	15,107
Net cash provided by (used in) financing activities	255,471	(99,101)
INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS	(110,563)	455,081
CASH AND CASH EQUIVALENTS, BEGINNING OF PERIOD	438,853	437,479
CASH AND CASH EQUIVALENTS, END OF PERIOD	$ 328,290	$ 892,560