9. Supplementary Balance Sheet Information

The following tables provide the details of selected balance sheet items as of the dates indicated (in thousands):

Inventories

	December 31,
	2016		2015
Raw materials	$	39,822	$	38,511
Work-in-process		8,012		10,138
Finished goods		9,511		9,266
Demo and consigned inventory		2,400		1,651
Total inventories	$	59,745	$	59,566

Property, Plant and Equipment, net

	December 31,
	2016			2015
Cost:
Land, buildings and improvements	$	38,384		$	48,154
Machinery and equipment		52,136			43,376
Total cost		90,520			91,530
Accumulated depreciation		(55,099	)		(50,980	)
Property, plant and equipment, net	$	35,421		$	40,550

As of December 31, 2016 and 2015, the Company has gross assets under capital lease of $13.2 million. The assets acquired under capital leases are included in land, buildings and improvements and machinery and equipment and the related amortization expense is included in depreciation expense. The Company also capitalized software development costs of $2.3 million, $1.9 million and $0.2 million in 2016, 2015 and 2014, respectively, in accordance with the guidance in ASC 350-40, “Internal-Use Software.”

The following table summarizes depreciation expense on property, plant and equipment, including demo units and assets under capital leases (in thousands):

	Year Ended December 31,
	2016		2015		2014
Depreciation expense	$	8,558	$	7,873	$	8,016

The following table summarizes total accumulated depreciation on assets under capital leases as of the dates indicated (in thousands):

	December 31,
	2016		2015
Accumulated depreciation on assets under capital leases	$	4,950	$	3,798

Accrued Expenses and Other Current Liabilities

The following table summarizes accrued expenses and other current liabilities as of the dates indicated (in thousands):

	December 31,
	2016		2015
Accrued compensation and benefits	$	9,647	$	7,357
Accrued warranty		3,142		3,335
Accrued restructuring		1,371		1,652
Accrued professional services		1,237		1,039
Accrued contingent considerations		2,775		—
Customer deposits		1,164		628
Other		7,612		7,171
Total	$	26,948	$	21,182

Accrued Warranty

The following table summarizes accrued warranty activities for the periods indicated (in thousands):

	Year Ended December 31,
	2016			2015			2014
Balance at beginning of year	$	3,335		$	3,044		$	3,315
Provision charged to cost of revenue		1,673			2,025			1,684
Acquisition related warranty accrual		23			132			90
Use of provision		(1,849	)		(1,454	)		(2,003	)
Divestiture of JK Lasers		—			(389	)		—
Foreign currency exchange rate changes		(40	)		(23	)		(42	)
Balance at end of year	$	3,142		$	3,335		$	3,044

Other Long Term Liabilities

The following table summarizes other long term liabilities as of the dates indicated (in thousands):

	December 31,
	2016		2015
Capital lease obligations	$	8,111	$	9,173
Accrued pension liabilities		5,957		3,693
Accrued contingent considerations		2,381		3,889
Other		2,264		2,690
Total		18,713		19,445