CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015	Sep. 30, 2015
Assets
Cash and cash equivalents	$ 135,365	$ 284,060	$ 168,681
Restricted cash	0	1,150	0
Accounts and notes receivable
Accounts and notes receivable, gross	536,242	423,600	558,755
Less: Allowance for doubtful accounts	(4,260)	(5,576)	(5,770)
Accounts and notes receivable, net	531,982	418,024	552,985
Inventories
Finished products	283,266	297,925	275,717
Raw materials	25,411	21,765	21,680
Products in process	2,753	1,008	1,161
Operating supplies and other	26,612	26,375	28,148
Inventories	338,042	347,073	326,706
Current deferred income taxes	0	0	39,301
Prepaid expenses	71,370	34,284	56,017
Total current assets	1,076,759	1,084,591	1,143,690
Investments and long-term receivables	38,914	40,558	40,516
Property, plant & equipment
Property, plant & equipment, cost	7,105,036	6,891,287	6,803,588
Reserve for depreciation, depletion & amortization	(3,876,743)	(3,734,997)	(3,683,961)
Property, plant & equipment, net	3,228,293	3,156,290	3,119,627
Goodwill	3,094,824	3,094,824	3,094,824
Other intangible assets, net	753,314	766,579	766,695
Other noncurrent assets	165,981	158,790	151,514
Total assets	8,358,085	8,301,632	8,316,866
Liabilities
Current maturities of long-term debt	131	130	130
Trade payables and accruals	163,139	175,729	195,536
Other current liabilities	197,642	177,620	216,411
Total current liabilities	360,912	353,479	412,077
Long-term debt	1,983,639	1,980,334	1,979,493
Noncurrent deferred income taxes	706,715	681,096	692,643
Deferred revenue	201,732	207,660	209,651
Other noncurrent liabilities	601,117	624,875	659,725
Total liabilities	3,854,115	3,847,444	3,953,589
Other commitments and contingencies (Note 8)
Equity
Common stock, $1 par value, Authorized 480,000 shares, Outstanding 132,309, 133,172 and 133,315 shares, respectively	132,309	133,172	133,315
Capital in excess of par value	2,829,806	2,822,578	2,812,593
Retained earnings	1,660,961	1,618,507	1,564,215
Accumulated other comprehensive loss	(119,106)	(120,069)	(146,846)
Total equity	4,503,970	4,454,188	4,363,277
Total liabilities and equity	$ 8,358,085	$ 8,301,632	$ 8,316,866