Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2019	Sep. 30, 2018
Current Assets:
Cash and cash equivalents	$ 243,912	$ 284,355
Short-term investments	26,118	41,461
Accounts receivable, net of allowance of $4,395 and $6,217, respectively	552,737	565,202
Inventories of materials and supplies, net	161,526	158,134
Prepaid expenses and other	63,711	66,398
Total current assets	1,048,004	1,115,550
Investments	60,247	98,696
Property, plant and equipment, net	4,886,948	4,857,382
Other Noncurrent Assets:
Goodwill	67,902	64,777
Intangible assets, net	70,531	73,207
Other assets	10,930	5,255
Total other noncurrent assets	149,363	143,239
Total assets	6,144,562	6,214,867
Current Liabilities:
Accounts payable	130,721	132,664
Accrued liabilities	242,986	244,504
Total current liabilities	373,707	377,168
Noncurrent Liabilities:
Long-term debt	491,227	493,968
Deferred income taxes	861,440	853,136
Other	84,989	93,606
Noncurrent liabilities - discontinued operations	14,579	14,254
Total noncurrent liabilities	1,452,235	1,454,964
Commitments and Contingencies (Note 14)
Shareholders' Equity:
Common stock, $.10 par value, 160,000,000 shares authorized, 112,080,262 and 112,008,961 shares issued as of March 31, 2019 and September 30, 2018, respectively, and 109,412,425 and 108,993,718 shares outstanding as of March 31, 2019 and September 30, 2018, respectively	11,208	11,201
Preferred stock, no par value, 1,000,000 shares authorized, no shares issued
Additional paid-in capital	493,421	500,393
Retained earnings	3,979,708	4,027,779
Accumulated other comprehensive income (loss)	(12,072)	16,550
Treasury stock, at cost, 2,667,837 shares and 3,015,243 shares as of March 31, 2019 and September 30, 2018, respectively	(153,645)	(173,188)
Total shareholders’ equity	4,318,620	4,382,735
Total liabilities and shareholders' equity	$ 6,144,562	$ 6,214,867