CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019	Sep. 30, 2019
Assets
Cash and cash equivalents	$ 1,084,100	$ 271,589	$ 90,411
Restricted cash	630	2,917	691
Accounts and notes receivable
Accounts and notes receivable, gross	647,362	573,241	727,900
Allowance for doubtful accounts	(3,155)	(3,125)	(2,960)
Accounts and notes receivable, net	644,207	570,116	724,940
Inventories
Finished products	384,575	391,666	364,164
Raw materials	34,562	31,318	31,250
Products in process	5,098	5,604	6,062
Operating supplies and other	31,226	29,720	28,184
Inventories	455,461	458,308	429,660
Other current assets	80,935	76,396	78,540
Total current assets	2,265,333	1,379,326	1,324,242
Investments and long-term receivables	41,778	60,709	57,059
Property, plant & equipment
Property, plant & equipment, cost	8,958,342	8,749,217	8,657,731
Allowances for depreciation, depletion & amortization	(4,614,543)	(4,433,179)	(4,370,386)
Property, plant & equipment, net	4,343,799	4,316,038	4,287,345
Operating lease right-of-use assets, net	431,227	408,189	410,833
Goodwill	3,172,112	3,167,061	3,167,061
Other intangible assets, net	1,107,091	1,091,475	1,071,330
Other noncurrent assets	229,193	225,995	221,803
Total assets	11,590,533	10,648,793	10,539,673
Liabilities
Current maturities of long-term debt	509,435	25	24
Trade payables and accruals	263,296	265,159	265,012
Other current liabilities	297,162	270,379	270,248
Total current liabilities	1,069,893	535,563	535,284
Long-term debt	2,777,072	2,784,315	2,783,068
Deferred income taxes, net	685,520	633,039	628,726
Deferred revenue	174,488	179,880	180,541
Operating lease liabilities	407,336	388,042	391,079
Other noncurrent liabilities	547,872	506,097	478,736
Total liabilities	5,662,181	5,026,936	4,997,434
Other commitments and contingencies (Note 8)
Equity
Common stock, $1 par value, Authorized 480,000 shares, Outstanding 132,454, 132,371 and 132,350 shares, respectively	132,454	132,371	132,350
Capital in excess of par value	2,797,222	2,791,353	2,785,245
Retained earnings	3,204,671	2,895,871	2,795,834
Accumulated other comprehensive loss	(205,995)	(197,738)	(171,190)
Total equity	5,928,352	5,621,857	5,542,239
Total liabilities and equity	$ 11,590,533	$ 10,648,793	$ 10,539,673