Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2017

Accounting Policies [Abstract]

Summary of Customers Comprising 10% or More of Total Revenues

The following table sets forth revenue generated from customers which comprise 10% or more of total revenue for the periods indicated: 

	Years Ended December 31,
	2017		2016		2015
Micron Technology, Inc.	11	%	17	%	15	%
Amkor Technologies, Inc.	10	%	15	%	14	%
Samsung Electronics, Co. Ltd.	*		25	%	19	%
SK hynix Inc.	*		12	%	13	%

* denotes less than 10% of total revenue.

Schedule of Estimated Useful Life

Property and equipment are recorded at cost, less accumulated depreciation. Depreciation is calculated using the straight-line method over the related assets' estimated useful lives:

Equipment, furniture and other	1 to 5 years
Leasehold improvements	Lesser of related lease term or 5 years
Building and improvements	Up to 30 years

Property and equipment, net consisted of the following (in thousands): 

	December 31,
	2017			2016
Equipment, furniture and other	$	26,029		$	28,071
Building and improvements		18,222			18,153
Land		5,300			5,300
Leasehold improvements		6,469			6,346
		56,020			57,870
Less: Accumulated depreciation and amortization		(21,578	)		(19,015	)
	$	34,442		$	38,855