Product Warranties

3 Months Ended

Mar. 31, 2015

Product Warranties Disclosures [Abstract]

Our standard warranty provides that if our systems do not function to published specifications, we will repair or replace the defective component, system or firmware without charge generally for a period of approximately three years. We generally extend to our customers the warranties provided to us by our suppliers, and accordingly, the majority of our warranty obligations to customers are typically intended to be covered by corresponding supplier warranties. For warranty costs not covered by our suppliers, we provide for estimated warranty costs in the period the revenue is recognized. There can be no assurance that our suppliers will continue to provide such warranties to us in the future or that our warranty obligations to our customers will be covered by corresponding warranties from our suppliers, the absence of which could have a material effect on our financial statements. Estimated liabilities for product warranties are included in accrued expenses.

Our warranty accrual and cost activity is as follows (in thousands):



	Three Months Ended
	March 31,
	2014			2015
Balance, beginning of period	$	2,965		$	3,363
Charges to operations	414			342
Deductions for payments made	(175		)	(385		)
Changes in estimates	40			149
Balance, end of period	$	3,244		$	3,469