Balance Sheet Information (Details 2) (USD $)	9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Dec. 31, 2010	Oct. 06, 2011 Metrology Segment Disposal	Sep. 30, 2011 Metrology Segment Disposal Y
Restricted Cash
Restricted cash	$ 22,901,000		$ 76,115,000	$ 22,900,000	$ 22,900,000
Restriction period on use of proceeds which are held in escrow (in years)					1
Accounts Receivable, net
Allowance for doubtful accounts receivable (in dollars)	500,000		500,000
Inventories
Raw materials	62,678,000		49,953,000
Work in process	28,026,000		33,181,000
Finished goods	36,814,000		25,353,000
Inventories	127,518,000		108,487,000
Goodwill
Balance at the beginning of the period	52,003,000	52,003,000
Write-off	(10,836,000)
Business Acquired	15,104,000
Balance at the end of the period	56,271,000
Accrued Warranty
Balance as of the beginning of year	9,238,000	6,675,000
Warranties issued during the year	7,935,000	7,242,000
Settlements made during the year	(6,870,000)	(4,906,000)
Balance as of the end of year	$ 10,303,000	$ 9,011,000