Fair Value Measurements (Tables)

9 Months Ended

Sep. 30, 2011

Fair Value Measurements

Schedule of assets and liabilities subject to fair value measurements

As of September 30, 2011
	Level 1		Level 2		Level 3		Balance
Assets
Money market funds (1)	$	256,878	$	—	$	—	$	256,878
Federally-sponsored and corporate debt securities (2)	—		599,918		—		599,918
Available-for-sale equity investment	283		—		—		283
Total assets	$	257,161	$	599,918	$	—	$	857,079
Liabilities
Convertible Senior Notes	$	257,467	$	—	$	—	$	257,467
Contingent consideration (3)	—		—		3,984		3,984
Total liabilities	$	257,467	$	—	$	3,984	$	261,451

	As of December 31, 2010
	Level 1		Level 2		Level 3		Balance
Assets
Money market funds (1)	$	91,206	$	—	$	—	$	91,206
Federally-sponsored and corporate debt securities (2)	—		507,375		—		507,375
Available-for-sale equity investment	373		—		—		373
Total assets	$	91,579	$	507,375	$	—	$	598,954
Liabilities
Convertible Senior Notes	$	421,721	$	—	$	—	$	421,721
Contingent consideration (3)	—		—		1,894		1,894
Total liabilities	$	421,721	$	—	$	1,894	$	423,615

(1)Included in cash and cash equivalents and marketable investments and cash—restricted on the accompanying consolidated balance sheets.

(2)Included in current and non-current marketable investments on the accompanying consolidated balance sheets. The fair value of these securities is derived using a market approach — i.e., from pricing models that rely on relevant observable market data, including interest rates, yield curves, recently reported trades of comparable securities, credit spreads and benchmark securities. See also Note 5—Marketable Investments—Held-to-Maturity Investments to these consolidated financial statements.

(3)Included in non-current liabilities on the accompanying consolidated balance sheets. The fair value of contingent consideration has been measured using a probability weighted discounted cash flow model which incorporates Level 3 inputs including estimated discount rates and the projected timing and amount of cash flows.

Reconciliation of the beginning and ending balances of contingent consideration measured at fair value using significant unobservable inputs (Level 3)

	Contingent Consideration
Balance July 1, 2011—Asset (Liability)	$	(618	)
Transfers into Level 3	—
Transfers out of Level 3	—
Total gains/(losses) realized/unrealized
Included in earnings	—
Included in other comprehensive income	34
Purchases (see Note 15)	(3,400		)
Sales	—
Issuances	—
Settlements	—
Balance September 30, 2011—Asset (Liability)	$	(3,984	)
Amount of total gains/(losses) for the three-month period ended September 30, 2011 included in earnings that are attributable to the change in unrealized gains or losses related to outstanding liabilities	$	—

	Contingent Consideration
Balance January 1, 2011—Asset (Liability)	$	(1,894	)
Transfers into Level 3	—
Transfers out of Level 3	—
Total gains/(losses) realized/unrealized
Included in earnings	—
Included in other comprehensive income	(51		)
Purchases (see Note 15)	(3,400		)
Sales	—
Issuances
Settlements	1,361
Balance September 30, 2011—Asset (Liability)	$	(3,984	)
Amount of total gains/(losses) for the nine-month period ended September 30, 2011 included in earnings that are attributable to the change in unrealized gains or losses related to the outstanding liability	$	—