CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018	Mar. 31, 2018
Assets
Cash and cash equivalents	$ 30,838	$ 40,037	$ 38,141
Restricted cash	270	4,367	8,373
Accounts and notes receivable
Accounts and notes receivable, gross	563,084	542,868	492,103
Allowance for doubtful accounts	(2,554)	(2,090)	(2,667)
Accounts and notes receivable, net	560,530	540,778	489,436
Inventories
Finished products	369,743	372,604	340,666
Raw materials	27,951	27,942	29,393
Products in process	4,976	3,064	1,303
Operating supplies and other	26,727	25,720	28,392
Inventories	429,397	429,330	399,754
Other current assets	62,816	64,633	75,495
Total current assets	1,083,851	1,079,145	1,011,199
Investments and long-term receivables	50,952	44,615	35,056
Property, plant & equipment
Property, plant & equipment, cost	8,559,549	8,457,619	8,116,439
Allowances for depreciation, depletion & amortization	(4,284,211)	(4,220,312)	(4,090,574)
Property, plant & equipment, net	4,275,338	4,237,307	4,025,865
Operating lease right-of-use assets, net	426,381	0	0
Goodwill	3,161,842	3,165,396	3,130,161
Other intangible assets, net	1,085,398	1,095,378	1,060,831
Other noncurrent assets	213,090	210,289	190,099
Total assets	10,296,852	9,832,130	9,453,211
Liabilities
Current maturities of long-term debt	24	23	22
Short-term debt	178,500	133,000	200,000
Trade payables and accruals	248,119	216,473	188,163
Other current liabilities	232,964	253,054	195,122
Total current liabilities	659,607	602,550	583,307
Long-term debt	2,780,589	2,779,357	2,775,687
Deferred income taxes, net	568,229	567,283	479,430
Deferred revenue	184,744	186,397	190,731
Operating lease liabilities	403,426	0	0
Other noncurrent liabilities	483,048	493,640	510,846
Total liabilities	5,079,643	4,629,227	4,540,001
Other commitments and contingencies (Note 8)
Equity
Common stock, $1 par value, Authorized 480,000 shares, Outstanding 132,069, 131,762, and 132,290 shares, respectively	132,069	131,762	132,290
Capital in excess of par value	2,789,864	2,798,486	2,787,848
Retained earnings	2,467,201	2,444,870	2,138,885
Accumulated other comprehensive loss	(171,925)	(172,215)	(145,813)
Total equity	5,217,209	5,202,903	4,913,210
Total liabilities and equity	$ 10,296,852	$ 9,832,130	$ 9,453,211