Summary Of Significant Accounting Policies (Schedule Of Balances Related To Property And Equipment) (Details) (USD $)	Dec. 31, 2011	Dec. 31, 2010
Summary Of Significant Accounting Policies [Abstract]
Land	$ 3,200,000	$ 3,200,000
Building and leasehold improvements	25,200,000	25,000,000
Equipment and furniture	117,300,000	100,600,000
Computer software	97,100,000	87,800,000
Property and equipment, Gross	242,800,000	216,600,000
Less: accumulated depreciation	94,266,000	78,074,000
Property and equipment, Net	$ 148,536,000	$ 138,554,000