Balance Sheet Information (Tables)

3 Months Ended

Mar. 31, 2014

Schedule of available-for-sale securities and gains and losses in accumulated other comprehensive income (loss)

Total available-for-sale securities and gains and losses in accumulated other comprehensive income (loss) consist of the following (in thousands):

	March 31, 2014
	Amortized Cost		Gains in Accumulated Other Comprehensive Income		Losses in Accumulated Other Comprehensive Income			Estimated Fair Value
U.S. treasuries	$	130,889	$	25	$	—		$	130,914
Corporate debt	73,410		76		(13		)	73,473
Government agency securities	59,004		11		—			59,015
Commercial paper	4,000		—		—			4,000
Total available-for-sale securities	$	267,303	$	112	$	(13	)	$	267,402

	December 31, 2013
	Amortized Cost		Gains in Accumulated Other Comprehensive Income		Losses in Accumulated Other Comprehensive Income			Estimated Fair Value
U.S. treasuries	$	130,956	$	22	$	(1	)	$	130,977
Corporate debt	77,582		55		(36		)	77,601
Government agency securities	61,004		9		—			61,013
Commercial paper	11,947		—		—			11,947
Total available-for-sale securities	$	281,489	$	86	$	(37	)	$	281,538

Summary of fair value of short-term investments that have been in an unrealized loss position for less than 12 months

The table below shows the fair value of short-term investments that have been in an unrealized loss position for less than 12 months (in thousands):

	March 31, 2014
	Less than 12 months					Total
	Estimated Fair Value		Gross Unrealized Losses			Estimated Fair Value		Gross Unrealized Losses
Corporate debt	$	25,916	$	(13	)	$	25,916	$	(13	)
Total	$	25,916	$	(13	)	$	25,916	$	(13	)

	December 31, 2013
	Less than 12 months					Total
	Estimated Fair Value		Gross Unrealized Losses			Estimated Fair Value		Gross Unrealized Losses
Corporate debt	$	37,654	$	(36	)	$	37,654	$	(36	)
U. S. treasuries	29,068		(1		)	29,068		(1		)
Total	$	66,722	$	(37	)	$	66,722	$	(37	)

Schedule of contractual maturities of available-for-sale debt securities

Contractual maturities of available-for-sale debt securities are as follows (in thousands):

	March 31, 2014
	Estimated Fair Value
Due in one year or less	$	207,913
Due in 1–2 years	47,621
Due in 2–3 years	11,868
Total available-for-sale securities	$	267,402

Schedule of inventories

Inventories are stated at the lower of cost (principally first-in, first-out) or market. Inventories consist of (in thousands):

	March 31,		December 31,
	2014		2013
Materials	$	27,486	$	34,301
Work in process	16,827		12,900
Finished goods	7,760		12,525
	$	52,073	$	59,726

Schedule of changes in warranty liability

Changes in our warranty liability during the period are as follows (in thousands):

	March 31,
	2014			2013
Balance as of the beginning of period	$	5,662		$	4,942
Warranties issued during the period	643			478
Settlements made during the period	(1,195		)	(1,341		)
Changes in estimate during the period	—			—
Balance as of the end of period	$	5,110		$	4,079

Schedule of the components of accumulated other comprehensive income

The components of accumulated other comprehensive income are (in thousands):

As of March 31, 2014	Gross			Taxes			Net
Translation adjustments	$	5,851		$	(392	)	$	5,459
Minimum pension liability	(1,160		)	424			(736		)
Unrealized gain on available-for-sale securities	99			(18		)	81
Accumulated other comprehensive income	$	4,790		$	14		$	4,804

As of December 31, 2013	Gross			Taxes			Net
Translation adjustments	$	5,718		$	(392	)	$	5,326
Minimum pension liability	(1,160		)	424			(736		)
Unrealized gain on available-for-sale securities	49			(18		)	31
Accumulated other comprehensive income	$	4,607		$	14		$	4,621