Trade receivables as of December 31, 2017, net of sales reserves and allowances (“SR&A”), were negative $0.8 billion, compared to negative $0.3 billion as of December 31, 2016, in line with a decrease in sales in the fourth quarter of 2017, compared to the fourth quarter of 2016.
Prepaid expenses as of December 31, 2017, were $1.1 billion, compared to $1.6 billion as of December 31, 2016, mainly due to a decrease of $0.5 billion in prepaid income tax.
Other current assets as of December 31, 2017, were $0.7 billion, compared to $1.3 billion as of December 31, 2016. The decrease was mainly due to the sale of our Mylan shares during 2017.
During September 2017, we entered into several agreements to sell certain non-core specialty products, including our global women’s health business. As a result of these agreements, we currently present net assets held for sale in the amount of $0.5 billion, with a corresponding reduction of other balance sheet assets, mainly intangible assets and goodwill. Net assets held for sale, as of December 31, 2016, were $0.7 billion, mainly comprised of the divestiture of certain assets and operations of Actavis Generics in the U.K. and Ireland that was completed in January 2017.
Accrued expenses as of December 31, 2017, were $3.0 billion, compared to $3.4 billion as of December 31, 2016. The decrease was mainly due to $0.5 billion in connection with the FCPA settlement with the DOJ and SEC.
Our working capital balance, which includes trade receivables net of SR&A, inventories, prepaid expenses and other current assets, trade payables, employee-related obligations, accrued expenses and other current liabilities, was negative $0.4 billion at December 31, 2017, compared to $0.3 billion as of December 31, 2016.
Investment in property, plant and equipment in 2017 was $0.9 billion, flat compared to 2016. Depreciation was $632 million in 2017, compared to $501 million in 2016.
Cash and cash equivalents and short-term and long-term investments as of December 31, 2017 were $1.1 billion, compared to $1.9 billion as of December 31, 2016. The decrease was mainly due to the sale of our Mylan shares during 2017.
Our cash on hand that is not used for ongoing operations is generally invested in bank deposits, as well as liquid securities that bear fixed and floating rates.
Our principal sources of short-term liquidity are our internally generated funds, liquid securities and available credit facilities, primarily our $3.0 billion syndicated revolving line of credit, which was not utilized as of December 31, 2017. We believe that these sources of liquidity, together with the proceeds from the working capital adjustment with Allergan and expected divestitures, are sufficient to meet our on-going operating needs.
2017 Debt Balance and Movements
As of December 31, 2017, our debt was $32.5 billion, a decrease of $3.3 billion compared to $35.8 billion at December 31, 2016. The decrease was mainly due to $4.4 billion of net debt repayments on our various term loans, our revolving credit facility and other short term loans, partially offset by foreign exchange fluctuations of $1.1 billion.
In January 2017, we repaid our GBP 510 million short-term loan.
In March 2017, we repaid at maturity a JPY 8.0 billion term loan.
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