Fair Value Measurements (Tables)

6 Months Ended

Jun. 30, 2011

Fair Value Measurements

Assets And Liabilities Measured At Fair Value On Recurring Basis

     Fair value as of June 30, 2011

			Quoted Prices in		Significant Other		Significant
	Fair Value		Active Markets for		Observable		Unobservable
	June 30,		Identical Assets		Inputs		Inputs
	2011		(Level 1)		(Level 2)		(Level 3)
Recurring:
Investments in money market and short term treasury instruments	$	186,873	$	186,873	$	—	$	—
Retained interest in entities		10,490		—		—		10,490
Total, net	$	197,363	$	186,873	$	—	$	10,490

     Fair value as of December 31, 2010

			Quoted Prices in		Significant Other		Significant
	Fair Value		Active Markets for		Observable		Unobservable
	December 31,		Identical Assets		Inputs		Inputs
	2010		(Level 1)		(Level 2)		(Level 3)
Recurring:
Investments in money market	$	177,816	$	177,816	$	—	$	—
Retained interest in entities		10,283		—		—		10,283
Total, net	$	188,099	$	177,816	$	—	$	10,283

Reconciliation Of Retained Interest

	2011
Balance January 1	$	10,283
Additions		—
Accretion of interest income		207
Balance June 30	$	10,490

Assets Measured At Fair Value On Nonrecurring Basis

	Quoted Prices in		Significant Other		Significant
	Active Markets for		Observable		Unobservable		Fair Value
	Identical Assets		Inputs		Inputs		June 30,		Total Impairment
	(Level 1)		(Level 2)		(Level 3)		2011		Losses
Non-financial assets:
Investment in real estate	$	—	$	1,224	$	1,701	$	2,925	$	1,697