Summary Of Significant Accounting Policies (Schedule Of Long-Term Investments Measured At Fair Value Using Significant Unobservable Inputs (Level 3 Inputs)) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2011	Dec. 31, 2010
Summary Of Significant Accounting Policies [Abstract]
Balance as of January 1	$ 35,297	$ 45,686
Net unrealized gains included in other comprehensive income	526	536
Sales of investments at par value	(11,150)	(10,925)
Balance as of December 31	24,673	35,297
Unrealized losses still held	$ 3,327	$ 3,853

Summary Of Significant Accounting Policies (Schedule Of Long-Term Investments Measured At Fair Value Using Significant Unobservable Inputs (Level 3 Inputs)) (Details) (USD $)
In Thousands, unless otherwise specified

12 Months Ended

Dec. 31, 2011

Dec. 31, 2010

Summary Of Significant Accounting Policies [Abstract]

Balance as of January 1

$ 35,297

$ 45,686

Net unrealized gains included in other comprehensive income

526

536

Sales of investments at par value

(11,150)

(10,925)

Balance as of December 31

24,673

35,297

Unrealized losses still held

$ 3,327

$ 3,853