Segment Information (Identifiable Assets By Segment) (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Segment Reporting Information [Line Items]
Total property and equipment, net	$ 219,031	$ 208,811
United States
Segment Reporting Information [Line Items]
Total property and equipment, net	168,144	160,825
United Kingdom
Segment Reporting Information [Line Items]
Total property and equipment, net	18,611	23,434
Other countries
Segment Reporting Information [Line Items]
Total property and equipment, net	$ 32,276	$ 24,552