Fair Value Measurements (Tables)

6 Months Ended

Jun. 30, 2013

Fair Value Measurements

Schedule of fair value of assets and liabilities measured on a recurring basis

The Company measures certain financial assets and liabilities at fair value on a recurring basis, including available-for-sale securities. The fair value of these certain financial assets was determined using the following inputs as of June 30, 2013 and December 31, 2012 (in thousands):

	Fair Value
	as of
	June 30, 2013		Level 1		Level 2		Level 3
Financial Assets:
Money Market Funds (1)	$	287,465	$	287,465	$	—	$	—
U.S. government debt securities (4)	35,000		—		35,000		—
Corporate debt securities (1)	38,839		—		38,839		—
Foreign government debt securities (2)	3,603		—		3,603		—
Financial Liabilities:
Debt (5)	$	225,000	$	—	$	225,000	$	—

	Fair Value
	as of
	December 31, 2012		Level 1		Level 2		Level 3
Financial Assets:
Money Market Funds (1)	$	47,086	$	47,086	$	—	$	—
U.S. government debt securities (3)	59,815		55,817		3,998		—
Corporate debt securities (3)	110,508		—		110,508		—
Foreign government debt securities (2)	2,421		—		2,421		—
Financial Liabilities:
Debt (5)	$	95,000	$	—	$	95,000	$	—

(1)  Included in cash and cash equivalents in the Company’s condensed consoldiated balance sheet.

(2)  Included in short-term marketable securities in the Company’s condensed consolidated balance sheet.

(3)  Included in short-term and long-term marketable securities in the Company’s condensed consolidated balance sheet.

(4)  Included in cash and cash equivalents, short-term and long-term marketable securities in the Company’s condensed consolidated balance sheet.

(5)  Included in current portion of long-term debt and long-term debt in the Company’s condensed consolidated balance sheet.