Business Segment Information (Revenue By Geographical Region) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2010	Sep. 30, 2010	Jun. 30, 2010	Mar. 31, 2010	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Segment Reporting Information [Line Items]
Total net revenues	$ 396,185	$ 372,496	$ 338,319	$ 291,607	$ 306,337	$ 392,669	$ 299,262	$ 201,570	$ 1,398,607	$ 1,199,838	$ 1,461,687
United States [Member]
Segment Reporting Information [Line Items]
Total net revenues									1,013,476	827,597	923,481
United Kingdom [Member]
Segment Reporting Information [Line Items]
Total net revenues									275,499	198,011	124,896
India [Member]
Segment Reporting Information [Line Items]
Total net revenues									44,772	56,311	233,466
Other [Member]
Segment Reporting Information [Line Items]
Total net revenues									$ 64,860	$ 117,919	$ 179,844