Investments (Tables)

6 Months Ended

Jun. 30, 2012

Aggregate Fair Value, Amortized Cost Basis and Net Unrealized Gains and Losses Included in Accumulated Other Comprehensive Income (Loss) of Available-for-Sale Investments

The following table sets forth the aggregate fair value, amortized cost basis and the net unrealized gains and losses included in accumulated other comprehensive income (loss) of our available-for-sale investments as of the dates indicated:

	As of:
	June 30, 2012						December 31, 2011							June 30, 2011
	Aggregate Fair Value		Amortized Cost		Net Unrealized Gains (Losses)		Aggregate Fair Value		Amortized Cost		Net Unrealized Gains (Losses)			Aggregate Fair Value		Amortized Cost		Net Unrealized Gains (Losses)
Available- for-Sale Investments:
Government obligations	$	0	$	0	$	0	$	100,517	$	100,480	$	37		$	100,679	$	100,664	$	15
Government agency obligations		0		0		0		31,351		31,354		(3	)		26,235		26,237		(2	)
Corporate obligations		0		0		0		16,620		16,633		(13	)		20,222		20,241		(19	)
	$	0	$	0	$	0	$	148,488	$	148,467	$	21		$	147,136	$	147,142		($6)

Unrealized Gains and Losses on Available-for-Sale Investments

The following table sets forth the unrealized gains and losses on available-for-sale investments that were included in other comprehensive income (loss) in the periods indicated:

	Three Months Ended June 30,				Six Months Ended June 30,
	2012		2011		2012		2011
Unrealized gains	$	2	$	46	$	0	$	0
Unrealized losses	$	0	$	0		($21)		($87)

Components of Investment Income Included in Interest Income

The following table sets forth the components of investment income included in Interest income in our Condensed Consolidated Statements of Income in the periods indicated:

	Three Months Ended June 30,				Six Months Ended June 30,
	2012		2011		2012		2011
Interest income on investments	$	75	$	116	$	216	$	271
Realized net gains on the sale of investments		26		51		40		196
Total investment income	$	101	$	167	$	256	$	467