Summary of Operations and Significant Accounting Policies (Long-Lived Assets by Geographic Region) (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Segment Reporting Information [Line Items]
Total long-lived assets	$ 71,808	$ 72,422
United States [Member]
Segment Reporting Information [Line Items]
Total long-lived assets	35,695	35,711
Israel [Member]
Segment Reporting Information [Line Items]
Total long-lived assets	23,910	23,750
Australia [Member]
Segment Reporting Information [Line Items]
Total long-lived assets	10,056	10,361
United Kingdom [Member]
Segment Reporting Information [Line Items]
Total long-lived assets	1,511	2,600
Netherlands [Member]
Segment Reporting Information [Line Items]
Total long-lived assets	$ 636