Segment Information (Identifiable Assets By Segment) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Identifiable assets	$ 4,099,541	$ 3,703,600
Long-lived assets	277,429	250,482
United States [Member]
Long-lived assets	223,076	200,319
United Kingdom [Member]
Long-lived assets	28,344	29,310
Other Countries [Member]
Long-lived assets	26,009	20,853
Enterprise Divisions [Member]
Identifiable assets	3,619,989	3,386,392
Online Services Division [Member]
Identifiable assets	$ 479,552	$ 317,208