CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017	Jun. 30, 2017
Assets
Cash and cash equivalents	$ 55,059	$ 141,646	$ 1,129,799
Restricted cash	6,056	5,000	0
Accounts and notes receivable
Accounts and notes receivable, gross	640,742	590,986	573,029
Less: Allowance for doubtful accounts	(2,628)	(2,649)	(2,943)
Accounts and notes receivable, net	638,114	588,337	570,086
Inventories
Finished products	343,948	327,711	318,465
Raw materials	29,684	27,152	27,106
Products in process	1,882	1,827	1,210
Operating supplies and other	28,250	27,648	28,148
Inventories	403,764	384,338	374,929
Other current assets	80,209	60,780	109,998
Total current assets	1,183,202	1,180,101	2,184,812
Investments and long-term receivables	41,989	35,115	38,888
Property, plant & equipment
Property, plant & equipment, cost	8,241,164	7,969,312	7,531,536
Allowances for depreciation, depletion & amortization	(4,134,750)	(4,050,381)	(3,992,728)
Property, plant & equipment, net	4,106,414	3,918,931	3,538,808
Goodwill	3,163,954	3,122,321	3,101,439
Other intangible assets, net	1,156,898	1,063,630	834,971
Other noncurrent assets	192,327	184,793	171,025
Total assets	9,844,784	9,504,891	9,869,943
Liabilities
Current maturities of long-term debt	23	41,383	525,776
Short-term debt	360,000	0	0
Trade payables and accruals	231,913	197,335	202,753
Other current liabilities	219,860	204,154	197,264
Total current liabilities	811,796	442,872	925,793
Long-term debt	2,776,906	2,813,482	2,809,293
Deferred income taxes, net	545,756	464,081	706,726
Deferred revenue	188,826	191,476	195,020
Other noncurrent liabilities	500,870	624,087	631,007
Total liabilities	4,824,154	4,535,998	5,267,839
Other commitments and contingencies (Note 8)
Equity
Common stock, $1 par value, Authorized 480,000 shares, Outstanding 132,268, 132,324 and 132,181 shares, respectively	132,268	132,324	132,181
Capital in excess of par value	2,788,486	2,805,587	2,797,269
Retained earnings	2,244,545	2,180,448	1,810,528
Accumulated other comprehensive loss	(144,669)	(149,466)	(137,874)
Total equity	5,020,630	4,968,893	4,602,104
Total liabilities and equity	$ 9,844,784	$ 9,504,891	$ 9,869,943