Fair Value Measurements (Tables)

9 Months Ended

Sep. 30, 2012

Fair Value Disclosures [Abstract]

Assets And Liabilities Measured At Fair Value On A Recurring Basis

Assets and Liabilities Measured at Fair Value on a Recurring Basis

	As of September 30, 2012		Quoted Prices In Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
	(in thousands)
Assets:
Cash and cash equivalents:
Money market funds	$	73,067	$	73,067	$	—	$	—
Corporate securities	35,299		—		35,299		—
Government securities	26,500		—		26,500		—
Municipal securities	4,199		—		4,199		—
Cash	185,062		185,062		—		—
Available-for-sale securities:
Agency securities	524,972		—		524,972		—
Corporate securities	506,229		—		502,751		3,478
Municipal securities	29,419		—		29,419		—
Government securities	21,505		—		21,505		—
Prepaid expenses and other current assets:
Foreign currency derivatives	4,112		—		4,112		—
Total assets	$	1,410,364	$	258,129	$	1,148,757	$	3,478
Accrued expenses and other current liabilities:
Foreign currency derivatives	4,624		—		4,624		—
Total liabilities	$	4,624	$	—	$	4,624	$	—

Assets Measured At Fair Value On A Recurring Basis Using Significant Unobservable Inputs

	Investments
	(in thousands)
Balance at December 31, 2011	$	3,696
Purchases of Level 3 securities	7,605
Transfers out of Level 3	(5,323		)
Total realized losses included in earnings	(2,500		)
Balance at September 30, 2012	$	3,478

Transfers out of Level 3 relate to certain of the Company's investments in convertible debt securities of early-stage entities that were classified as available-for-sale investments to cost method investments upon conversion to equity ownership, which are included in Other assets in the accompanying condensed consolidated balance sheets. Realized losses included in earnings for the period are reported in Other income (expense), net in the accompanying condensed consolidated statements of income.