CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014
CASH PROVIDED BY OPERATIONS:
Net income	$ 208,404	$ 92,439
Adjustments to reconcile net income to net cash provided by operations:
Depreciation and amortization	185,241	148,551
Deferred income taxes	(12,571)	1,063
Provision for pension and other postemployement benefits	15,776	12,410
Share-based compensation expense	16,370	15,467
Gain on disposals of property, plant and equipment	(175)	(251)
Other postretirement benefit claims paid	(2,358)	(1,815)
Contributions to pension plans	(4,698)	(28,445)
Asset Impairment Charges	0	8,300
Changes in current assets and liabilities:
Receivables - trade and other	47,292	(78,200)
Prepaid expenses and other current assets	(10,710)	(6,081)
Accounts payable	14,681	(3,823)
Accrued income taxes	3,809	(8,354)
Deferred revenues	4,913	(16,772)
Other current liabilities	(14,769)	15,819
Net changes in other noncurrent assets and liabilities	(2,485)	(793)
Net cash provided by operations	448,720	149,515
CASH USED IN INVESTING ACTIVITIES:
Capital expenditures	(616,398)	(787,296)
Proceeds from disposals of property, plant and equipment	2,298	7,897
Net cash used in investing activities	(614,100)	(779,399)
CASH PROVIDED BY FINANCING ACTIVITIES:
Proceeds from borrowings	220,000	793,380
Repayments of borrowings	(170,000)	0
Dividends paid	(25,220)	(12,556)
Debt issue costs	0	(687)
Excess tax benefit (deficit) from share-based compensation	0	(563)
Proceeds from exercise of share options	0	4,472
Net cash provided by financing activities	24,780	784,046
(DECREASE) INCREASE IN CASH AND CASH EQUIVALENTS	(140,600)	154,162
CASH AND CASH EQUIVALENTS, BEGINNING OF PERIOD	339,154	1,092,844
CASH AND CASH EQUIVALENTS, END OF PERIOD	$ 198,554	$ 1,247,006