Segment Information (Schedule Of Assets By Geographic Area) (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Segment Reporting Information [Line Items]
Assets	$ 697,654	$ 677,442
United States [Member]
Segment Reporting Information [Line Items]
Assets	537,015	501,157
Germany [Member]
Segment Reporting Information [Line Items]
Assets	23,220	24,264
Other Europe [Member]
Segment Reporting Information [Line Items]
Assets	81,124	86,494
Asia Pacific [Member]
Segment Reporting Information [Line Items]
Assets	$ 56,295	$ 65,527