Investments (Tables)

12 Months Ended

Dec. 31, 2011

Investments [Abstract]

Schedule Of Held-To-Maturity Securities

	Cost or Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Estimated Fair Value
	(In thousands)
December 31, 2011	$	55,694	$	—	$	—	$	55,694
December 31, 2010	$	20,069	$	—	$	—	$	20,069

Schedule Of Available-For-Sale And Held-To-Maturity Securities Included In Consolidated Balance Sheets

	December 31, 2011				December 31, 2010
	Available- for-sale securities:		Held-to- maturity securities:		Available- for-sale securities		Held-to- maturity securities:
	(In thousands)
Short-term investments	$	—	$	55,694	$	1	$	20,069

Schedule Of Held-To-Maturity Securities Based On Maturity Dates

	December 31, 2011		December 31, 2010
	(In thousands)
One year or less	$	55,694	$	20,069

Schedule Of Proceeds From Sale Of Available-For-Sale Securities And Gross Realized Gains And Losses

	Year Ended December 31,
	2011		2010		2009
	(In thousands)
Proceeds	$	—	$	—	$	4,170
Gross realized investment gains		—		—		834
Gross realized investment losses	$	—	$	—	$	652