Cash, Cash Equivalents and Marketable Securities (Tables)

9 Months Ended

Sep. 30, 2012

Cash Cash Equivalents and Marketable Securities [Abstract]

Schedule of cash and cash equivalents

The following table summarizes our cash and investments in cash equivalents and marketable securities held by investment managers and overnight investments:

	September 30,			December 31,
	2012			2011
	(in thousands)
Overnight Holdings
Money market funds (cash equivalents)	$	46,079		$	71,350
Investment Holdings
Money market funds (cash equivalents)		67,395			59,587
Marketable securities		51,702			56,987
		165,176			187,924
Cash held in demand accounts		102,761			113,968
Outstanding checks		(14,017	)		(33,697	)
Total cash, cash equivalents and marketable securities	$	253,920		$	268,195
Cash and cash equivalents	$	202,218		$	211,208
Marketable securities		51,702			56,987
	$	253,920		$	268,195

Schedule of fair value assets and liabilities measured on recurring basis

The following table summarizes the levels of fair value measurements of our financial assets:

	Fair Value Measurements
	(in thousands)
	September 30,
	2012		Level 1		Level 2		Level 3
Money market funds	$	113,474	$	113,474	$	—	$	—
Municipal bonds		51,702		—		51,702		—
Total	$	165,176	$	113,474	$	51,702	$	—

	Fair Value Measurements
	(in thousands)
	December 31,
	2011		Level 1		Level 2		Level 3
Money market funds	$	130,937	$	130,937	$	—	$	—
Municipal bonds		56,987		—		56,987		—
Total	$	187,924	$	130,937	$	56,987	$	—

Schedule of available for sale securities reconciliation

The following is a summary of our available-for-sale marketable securities:

			Gross		Gross
	Amortized		Unrealized		Unrealized			Estimated
	Cost		Gains		Losses			Fair Value
			(in thousands)
September 30, 2012:
Municipal bonds	$	51,584	$	133	$	(15	)	$	51,702
December 31, 2011:
Municipal bonds	$	56,945	$	90	$	(48	)	$	56,987

Contractual maturities of marketable securities

As of September 30, 2012, the contractual maturities of our marketable securities were as follows:

	Amortized Cost		Estimated Fair Value
	(in thousands)
Less than one year	$	23,513	$	23,552
One to five years		28,071		28,150
Total	$	51,584	$	51,702