Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2019	Sep. 30, 2019
Current Assets:
Cash and cash equivalents	$ 355,010	$ 347,943
Short-term investments	57,044	52,960
Accounts receivable, net of allowance of $4,037 and $9,927, respectively	500,947	495,602
Inventories of materials and supplies, net	148,688	149,653
Prepaid expenses and other	92,955	68,928
Total current assets	1,154,644	1,115,086
Investments	35,149	31,991
Property, plant and equipment, net	4,412,359	4,502,084
Other Noncurrent Assets:
Goodwill	82,786	82,786
Intangible assets, net	86,329	86,716
Operating lease right-of-use asset	52,190
Other assets	18,053	20,852
Total other noncurrent assets	239,358	190,354
Total assets	5,841,510	5,839,515
Current Liabilities:
Accounts payable	122,609	123,146
Accrued liabilities	296,738	287,092
Total current liabilities	419,347	410,238
Noncurrent Liabilities:
Long-term debt, net	479,355	479,356
Deferred income taxes	798,802	806,611
Other	153,026	115,746
Noncurrent liabilities - discontinued operations	15,443	15,341
Total noncurrent liabilities	1,446,626	1,417,054
Commitments and Contingencies (Note 16)
Shareholders' Equity:
Common stock, $.10 par value, 160,000,000 shares authorized, 112,151,563 and 112,080,262 shares issued as of December 31, 2019 and September 30, 2019, respectively, and 108,877,209 and 108,437,904 shares outstanding as of December 31, 2019 and September 30, 2019, respectively	11,215	11,208
Preferred stock, no par value, 1,000,000 shares authorized, no shares issued	0	0
Additional paid-in capital	499,277	510,305
Retained earnings	3,666,260	3,714,307
Accumulated other comprehensive income (loss)	(28,119)	(28,635)
Treasury stock, at cost, 3,274,354 shares and 3,642,358 shares as of December 31, 2019 and September 30, 2019, respectively	(173,096)	(194,962)
Total shareholders’ equity	3,975,537	4,012,223
Total liabilities and shareholders' equity	$ 5,841,510	$ 5,839,515

Carrying value as of the balance sheet date of liabilities incurred (and for which invoices have typically been received) and payable to vendors for goods and services received that are used in an entity's business. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

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- Definition

Carrying value as of the balance sheet date of obligations incurred and payable, pertaining to costs that are statutory in nature, are incurred on contractual obligations, or accumulate over time and for which invoices have not yet been received or will not be rendered. Examples include taxes, interest, rent and utilities. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).