Basis Of Presentation (Details) (USD $)	6 Months Ended
	Jun. 30, 2012	Dec. 31, 2011
Restricted Cash and Cash Equivalents Items [Line Items]
Number of Revenue Sources from Products and Services	4
Deferred Revenue [Abstract]
Deferred revenue, gross	$ 36,700,000	$ 20,700,000
Deferred costs, gross	11,400,000	5,700,000
Interest-bearing Deposits
Deferred Revenue [Abstract]
Restricted cash	$ 200,000