Other Assets

Other assets are summarized as follows:



(in millions)	December 31, 2017		September 30, 2017
Long-term receivables	$	204	$	211
Investments in equity affiliates	6		7
Exchange and rental assets (net of accumulated depreciation of $109 at December 31, 2017 and $106 at September 30, 2017)	71		71
Other	248		242
Other Assets	$	529	$	531

Long-Term Receivables

Long-term receivables expected to be collected beyond the next twelve months are principally comprised of unbilled accounts receivables pursuant to sales recorded under the percentage-of-completion method of accounting that have not yet been billed to customers in accordance with applicable contract terms.

Investments in Equity Affiliates

The Company's investments in equity affiliates primarily consist of seven joint ventures, each 50 percent owned and accounted for under the equity method. The Company records income or loss from equity affiliates in Other income, net on the Condensed Consolidated Statement of Operations. The Company's sales to equity affiliates were $50 million and $67 million for the three months ended December 31, 2017 and 2016, respectively. Deferred profit from sales to equity affiliates was $1 million at December 31, 2017, and $2 million at September 30, 2017.

Exchange and Rental Assets

Exchange and rental assets consist primarily of Company products that are either exchanged or rented to customers on a short-term basis in connection with warranty and other service-related activities. These assets are recorded at acquisition cost or production cost and depreciated using the straight-line method over their estimated lives, up to 15 years. Depreciation methods and lives are reviewed periodically with any changes recorded on a prospective basis. Depreciation expense for exchange and rental assets was $3 million and $2 million for the three months ended December 31, 2017 and 2016, respectively.