CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015	Mar. 31, 2015
Assets
Cash and cash equivalents	$ 191,886	$ 284,060	$ 392,657
Restricted cash	0	1,150	0
Accounts and notes receivable
Accounts and notes receivable, gross	449,538	423,600	375,196
Less: Allowance for doubtful accounts	(5,775)	(5,576)	(5,244)
Accounts and notes receivable, net	443,763	418,024	369,952
Inventories
Finished products	288,891	297,925	285,313
Raw materials	22,160	21,765	21,203
Products in process	1,221	1,008	1,189
Operating supplies and other	25,486	26,375	25,987
Inventories	337,758	347,073	333,692
Current deferred income taxes	0	0	39,881
Prepaid expenses	34,096	34,284	58,483
Total current assets	1,007,503	1,084,591	1,194,665
Investments and long-term receivables	38,895	40,558	41,613
Property, plant & equipment
Property, plant & equipment, cost	6,984,417	6,891,287	6,671,537
Reserve for depreciation, depletion & amortization	(3,786,590)	(3,734,997)	(3,587,444)
Property, plant & equipment, net	3,197,827	3,156,290	3,084,093
Goodwill	3,094,824	3,094,824	3,094,824
Other intangible assets, net	753,372	766,579	764,072
Other noncurrent assets	154,604	158,790	147,258
Total assets	8,247,025	8,301,632	8,326,525
Liabilities
Current maturities of long-term debt	131	130	365,441
Trade payables and accruals	185,653	175,729	157,829
Other current liabilities	170,701	177,620	180,066
Total current liabilities	356,485	353,479	703,336
Long-term debt	1,981,425	1,980,334	1,888,365
Noncurrent deferred income taxes	663,364	681,096	682,849
Deferred revenue	205,892	207,660	212,987
Other noncurrent liabilities	618,806	624,875	678,821
Total liabilities	$ 3,825,972	$ 3,847,444	$ 4,166,358
Other commitments and contingencies (Note 8)
Equity
Common stock, $1 par value, Authorized 480,000 shares, Outstanding 133,348, 133,172 and 132,660 shares, respectively	$ 133,348	$ 133,172	$ 132,660
Capital in excess of par value	2,823,116	2,822,578	2,765,391
Retained earnings	1,584,344	1,618,507	1,418,901
Accumulated other comprehensive loss	(119,755)	(120,069)	(156,785)
Total equity	4,421,053	4,454,188	4,160,167
Total liabilities and equity	$ 8,247,025	$ 8,301,632	$ 8,326,525