Segment Reporting (Schedule Of Net Long-Lived Assets By Principal Geographic Areas) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Revenues from External Customers and Long-Lived Assets [Line Items]
Net Assets	$ 281,214	$ 245,177
Americas [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net Assets	248,494	211,212
Americas [Member] | United States [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net Assets	245,511	208,725
Americas [Member] | Canada [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net Assets	2,114	2,487
Americas [Member] | Brazil [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net Assets	869
Europe, The Middle East And Africa [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net Assets	29,041	29,373
Europe, The Middle East And Africa [Member] | United Kingdom [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net Assets	12,959	12,440
Europe, The Middle East And Africa [Member] | Germany [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net Assets	5,733	6,144
Europe, The Middle East And Africa [Member] | Switzerland [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net Assets	3,076	3,411
Europe, The Middle East And Africa [Member] | France [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net Assets	3,127	3,079
Europe, The Middle East And Africa [Member] | Netherlands [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net Assets	2,956	3,034
Europe, The Middle East And Africa [Member] | Other Europe [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net Assets	1,190	1,265
Asia Pacific Region [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net Assets	3,679	4,592
Asia Pacific Region [Member] | Japan [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net Assets	690	1,016
Asia Pacific Region [Member] | Australia [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net Assets	1,801	2,484
Asia Pacific Region [Member] | Other Asia Pacific [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net Assets	$ 1,188	$ 1,092