Balance Sheet Information (Tables)

3 Months Ended

Mar. 31, 2013

Schedule of available-for-sale securities

Available-for-sale securities consist of the following (in thousands):

	March 31, 2013
	Amortized Cost		Gains in Accumulated Other Comprehensive Income		Losses in Accumulated Other Comprehensive Income			Estimated Fair Value
Treasury bills	$	271,168	$	33	$	—		$	271,201
Government agency securities	8,055		—		—			8,055
Corporate bonds	63,488		38		(27		)	63,499
Commercial paper	19,992		—		—			19,992
Total available-for-sale securities	$	362,703	$	71	$	(27	)	$	362,747

	December 31, 2012
	Amortized Cost		Gains in Accumulated Other Comprehensive Income		Losses in Accumulated Other Comprehensive Income		Estimated Fair Value
Treasury bills	$	184,102	$	76	$	—	$	184,178
Government agency securities	8,056		—		—		8,056
Total available-for-sale securities	$	192,158	$	76	$	—	$	192,234

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 as of March 31, 2013 (in thousands):

	Estimated Fair value		Unrealized Losses
Corporate bonds	$	28,491	$	(27	)
Total	$	28,491	$	(27	)

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

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

	March 31, 2013
	Estimated Fair Value
Due in one year or less	$	288,752
Due in 1—2 years	32,811
Due in 2—3 years	41,184
Total available-for-sale securities	$	362,747

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,
	2013		2012
Materials	$	44,219	$	36,523
Work in process	17,248		13,363
Finished goods	6,222		9,921
	$	67,689	$	59,807

Schedule of changes in warranty liability

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

	Three months ended
	March 31,
	2013			2012
Balance as of the beginning of period	$	4,942		$	8,731
Warranties issued during the period	478			696
Settlements made during the period	(1,341		)	(1,840		)
Changes in estimate during the period	—			327
Balance as of the end of period	$	4,079		$	7,914

Schedule of the components of accumulated other comprehensive income

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

As of March 31, 2013	Gross			Taxes			Net
Translation adjustments	$	6,290		$	(352	)	$	5,938
Minimum pension liability	(1,285		)	510			(775		)
Unrealized gain on available-for-sale securities	44			(13		)	31
Accumulated other comprehensive income	$	5,049		$	145		$	5,194

As of December 31, 2012	Gross			Taxes			Net
Translation adjustments	$	7,040		$	(339	)	$	6,701
Minimum pension liability	(1,285		)	510			(775		)
Unrealized gain on available-for-sale securities	76			(29		)	47
Accumulated other comprehensive income	$	5,831		$	142		$	5,973