NOTE 10 - SUPPLEMENTAL FINANCIAL STATEMENT INFORMATION

Temporary Investments

Temporary investments with an original maturity of three months or less are treated as cash equivalents and are stated at cost. Temporary investments totaled $628 million and $661 million at September 30, 2018 and December 31, 2017, respectively.

Accounts and Notes Receivable



In millions	September 30, 2018		December 31, 2017
Accounts and notes receivable, net:
Trade	$	3,333	$	3,017
Other	247		270
Total	$	3,580	$	3,287

The allowance for doubtful accounts was $81 million and $73 million at September 30, 2018 and December 31, 2017, respectively.

Inventories



In millions	September 30, 2018		December 31, 2017
Raw materials	$	287	$	274
Finished pulp, paper and packaging	1,109		1,337
Operating supplies	609		615
Other	125		87
Total	$	2,130	$	2,313

Depreciation

Accumulated depreciation was $21.0 billion and $20.5 billion at September 30, 2018 and December 31, 2017, respectively. Depreciation expense was $315 million and $317 million for the three months ended September 30, 2018 and 2017, respectively and $930 million and $926 million for the nine months ended September 30, 2018 and 2017, respectively.

Interest

Interest payments made during the nine months ended September 30, 2018 and 2017 were $606 million and $600 million, respectively.

Amounts related to interest were as follows:



	Three Months Ended September 30,				Nine Months Ended September 30,
In millions	2018		2017		2018		2017
Interest expense	$	184	$	198	$	547	$	571
Interest income	51		46		146		140
Capitalized interest costs	9		6		26		18

Asset Retirement Obligations

The Company had recorded liabilities of $86 million related to asset retirement obligations at September 30, 2018 and December 31, 2017.