Balance Sheet Components

Selected balance sheet components consist of the following:

Accounts receivable, net



(In millions)	December 31, 2017		December 31, 2016
Trade receivables, net	$	3,173.1	$	3,015.4
Other receivables	439.3		295.5
Accounts receivable, net	$	3,612.4	$	3,310.9

Trade receivables, net includes certain sales allowances totaling $1.98 billion and $2.05 billion at December 31, 2017 and 2016, respectively. See Note 2 Summary of Significant Accounting Policies for further discussion of such allowances. Total allowances for doubtful accounts were $75.3 million and $59.0 million at December 31, 2017 and 2016, respectively. Mylan performs ongoing credit evaluations of its customers and generally does not require collateral. Approximately 35% and 45% of the accounts receivable balances represent amounts due from three customers at December 31, 2017 and 2016, respectively.

Inventories



(In millions)	December 31, 2017		December 31, 2016
Raw materials	$	895.5	$	783.4
Work in process	384.7		436.0
Finished goods	1,262.5		1,237.0
Inventories	$	2,542.7	$	2,456.4

Inventory reserves totaled $171.0 million and $174.6 million at December 31, 2017 and 2016, respectively. Included as a component of cost of sales is expense related to the net realizable value of inventories of $229.3 million, $195.7 million and $221.4 million for the years ended December 31, 2017, 2016 and 2015, respectively.

Prepaid expenses and other current assets



(In millions)	December 31, 2017		December 31, 2016
Prepaid expenses	$	119.8	$	169.1
Restricted cash	77.8		148.1
Available-for-sale securities	76.7		83.7
Fair value of financial instruments	88.9		62.2
Trading securities	33.9		29.6
Other current assets	369.0		263.7
Prepaid expenses and other current assets	$	766.1	$	756.4

Prepaid expenses consists primarily of prepaid rent, insurance and other individually insignificant items. At December 31, 2017, restricted cash principally relates to amounts deposited in escrow for potential contingent consideration payments related to the Company’s acquisition of Agila Specialties (“Agila”).

Property, plant and equipment, net



(In millions)	December 31, 2017		December 31, 2016
Machinery and equipment	$	2,414.5	$	2,227.9
Buildings and improvements	1,191.7		1,106.5
Construction in progress	252.9		328.8
Land and improvements	143.1		144.7
Gross property, plant and equipment	4,002.2		3,807.9
Accumulated depreciation	1,663.1		1,485.7
Property, plant and equipment, net	$	2,339.1	$	2,322.2

Capitalized software costs included on our Consolidated Balance Sheets were $143.0 million and $145.4 million, net of accumulated depreciation, at December 31, 2017 and 2016, respectively. The Company periodically reviews the estimated useful lives of assets and makes adjustments when appropriate. Depreciation expense was approximately $287.6 million, $259.4 million and $186.1 million for the years ended December 31, 2017, 2016 and 2015, respectively.

Other assets



(In millions)	December 31, 2017		December 31, 2016
Equity method investments, clean energy investments	$	226.0	$	320.6
Equity method investments, Sagent Agila	—		75.8
Other long-term assets	79.6		172.2
Other assets	$	305.6	$	568.6

Trade accounts payable



(In millions)	December 31, 2017		December 31, 2016
Accounts payable	$	976.0	$	939.5
Other payables	476.5		408.6
Trade accounts payable	$	1,452.5	$	1,348.1

Other current liabilities



(In millions)	December 31, 2017		December 31, 2016
Accrued sales allowances	$	818.0	$	809.0
Payroll and employee benefit plan accruals	404.6		409.8
Legal and professional accruals, including litigation accruals	241.1		720.4
Contingent consideration	167.8		256.9
Restructuring	91.5		138.6
Compulsory acquisition proceeding	—		70.2
Equity method investments, clean energy investments	56.7		64.7
Accrued interest	42.3		41.0
Fair value of financial instruments	31.1		15.3
Other	1,111.4		732.6
Other current liabilities	$	2,964.5	$	3,258.5

Included in legal and professional accruals at December 31, 2016 was $465 million for a settlement with the U.S. Department of Justice and other government agencies related to the classification of the EpiPen® Auto-Injector and EpiPen Jr® Auto-Injector (collectively, “EpiPen® Auto-Injector”) for purposes of the Medicaid Drug Rebate Program (the “Medicaid Drug Rebate Program Settlement”). The Medicaid Drug Rebate Program Settlement was paid during 2017, as discussed further in Note 18 Litigation.

On March 31, 2017, the Company announced that Meridian Medical Technologies (“Meridian”), a Pfizer Inc. (“Pfizer”) company that manufactures the EpiPen® Auto-Injector, expanded a voluntary recall of select lots of EpiPen® Auto-Injector and EpiPen Jr® Auto-Injector to include additional lots distributed in the U.S. and other markets in consultation with the FDA (the “EpiPen® Auto-Injector Recall”). This recall was conducted as a result of the receipt of two previously disclosed reports outside of the U.S. of the failure to activate the device due to a potential defect in a supplier component. Both reports were related to the single lot that was previously recalled. The expanded voluntary recall was initiated in the U.S. and also extended to additional markets in Europe, Asia, North and South America. The Company is replacing recalled devices at no cost to the consumer. Estimated costs to Mylan related to product recalls are based on a formal campaign soliciting return of the product and are accrued when they are deemed to be probable and can be reasonably estimated. As of December 31, 2017, the Company recorded an accrual for certain costs of the recall but there can be no assurance that future costs related to the recall will not exceed amounts recorded. In addition, Meridian is contractually obligated to reimburse Mylan for costs related to the EpiPen® Auto-Injector Recall, and the Company has recorded an asset for the recovery of such costs.

Other long-term obligations



(In millions)	December 31, 2017		December 31, 2016
Employee benefit liabilities	$	408.2	$	396.7
Equity method investments, clean energy investments	171.8		302.3
Contingent consideration	285.9		307.7
Tax contingencies	237.7		239.3
Other	132.1		112.6
Other long-term obligations	$	1,235.7	$	1,358.6