Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2017

Accounting Policies [Abstract]

Schedule of accounts, notes, loans and financing receivable

ctivity within the Company’s allowance for doubtful accounts for the periods presented is as follows:

	2017			2016			2015
Beginning balance	$	3,477		$	3,534		$	2,723
Additions	674			872			1,342
Deductions (write-offs/recoveries) from reserve	(1,299		)	(929		)	(531		)
Ending balance	$	2,852		$	3,477		$	3,534

Summary of product warranty activity

he following table summarizes product warranty activity during 2017 and 2016:

	2017			2016
Beginning balance	$	2,280		$	1,880
Charges to expense	1,042			1,723
Costs incurred	(1,248		)	(1,323		)
Ending balance	$	2,074		$	2,280

Revenue and related development costs, customer-funded research and development costs

evenue and related development costs from customer-funded research and development are as follows:

	Year Ended December 31,
	2017		2016		2015
Customer-funded service sales	$	2,621	$	1,400	$	3,002
Customer-funded costs included in costs of service sales	1,510		498		1,546

(

Schedule of reconciliation of basic and diluted weighted average common shares outstanding

reconciliation of the basic and diluted weighted average common shares outstanding is as follows:

	2017	2016	2015
Weighted average common shares outstanding—basic	16,419	15,834	15,625
Dilutive common shares issuable in connection with stock plans	—	—	209
Weighted average common shares outstanding—diluted	16,419	15,834	15,834

(