Income Tax Expense (Details 2) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011 Y
Net operating loss ("NOL") carry forwards
Federal net operating loss carry forwards	$ 78,230
State net operating loss carry forwards	20,413
Foreign net operating loss carry forwards	37,375
Period for which foreign NOL can be carried forward (in years)	10
Tax credit carry forwards
Foreign tax credit carry forwards	30,067
Research and development tax credit carry forwards	9,003
Alternative minimum tax credit carry forwards	367
State tax credits carry forward	1,901
Other non-U.S. tax credits	$ 543