Balance Sheet Related Information (Details) (Allowance For Doubtful Accounts [Member], As Restated [Member], USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Allowance For Doubtful Accounts [Member] | As Restated [Member]
Allowance for doubtful accounts
Balance at the beginning of the year	$ 6,635	$ 6,334	$ 5,896
Charged to expense (income)	3,648	2,429	3,138
Write-offs and currency translation adjustments	(2,737)	(2,128)	(2,700)
Balance at the end of the year	$ 7,546	$ 6,635	$ 6,334