CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015	Jun. 30, 2015
Assets
Cash and cash equivalents	$ 91,902	$ 284,060	$ 74,736
Restricted cash	0	1,150	0
Accounts and notes receivable
Accounts and notes receivable, gross	537,127	423,600	495,781
Less: Allowance for doubtful accounts	(4,332)	(5,576)	(5,370)
Accounts and notes receivable, net	532,795	418,024	490,411
Inventories
Finished products	295,405	297,925	292,932
Raw materials	25,366	21,765	21,610
Products in process	2,223	1,008	1,461
Operating supplies and other	24,872	26,375	25,825
Inventories	347,866	347,073	341,828
Current deferred income taxes	0	0	39,562
Prepaid expenses	50,844	34,284	75,663
Total current assets	1,023,407	1,084,591	1,022,200
Investments and long-term receivables	38,924	40,558	41,603
Property, plant & equipment
Property, plant & equipment, cost	7,052,051	6,891,287	6,752,916
Reserve for depreciation, depletion & amortization	(3,834,680)	(3,734,997)	(3,637,392)
Property, plant & equipment, net	3,217,371	3,156,290	3,115,524
Goodwill	3,094,824	3,094,824	3,094,824
Other intangible assets, net	754,341	766,579	767,995
Other noncurrent assets	161,246	158,790	153,737
Total assets	8,290,113	8,301,632	8,195,883
Liabilities
Current maturities of long-term debt	131	130	14,124
Short-term debt (line of credit)	0	0	138,500
Trade payables and accruals	176,476	175,729	190,904
Other current liabilities	156,071	177,620	163,112
Total current liabilities	332,678	353,479	506,640
Long-term debt	1,982,527	1,980,334	1,893,737
Noncurrent deferred income taxes	683,999	681,096	686,171
Deferred revenue	203,800	207,660	211,429
Other noncurrent liabilities	607,778	624,875	670,949
Total liabilities	3,810,782	3,847,444	3,968,926
Other commitments and contingencies (Note 8)
Equity
Common stock, $1 par value, Authorized 480,000 shares, Outstanding 133,027, 133,172 and 132,984 shares, respectively	133,027	133,172	132,984
Capital in excess of par value	2,826,471	2,822,578	2,791,232
Retained earnings	1,639,267	1,618,507	1,453,752
Accumulated other comprehensive loss	(119,434)	(120,069)	(151,011)
Total equity	4,479,331	4,454,188	4,226,957
Total liabilities and equity	$ 8,290,113	$ 8,301,632	$ 8,195,883