Fair Value Measurements (Tables)

9 Months Ended

Sep. 30, 2012

Fair Value Measurements

Schedule of assets and liabilities subject to fair value measurements

	As of September 30, 2012
	Level 1		Level 2		Level 3		Balance
Assets
Money market funds (1)	$	146,933	$	—	$	—	$	146,933
Federally-sponsored and corporate debt securities (2)	—		488,901		—		488,901
Available-for-sale equity investment	529		—		—		529
Total assets	$	147,462	$	488,901	$	—	$	636,363
Liabilities
Convertible notes maturing in 2016 (3)	$	—	$	329,950	$	—	$	329,950
Contingent consideration (4)	—		—		7,298		7,298
Total liabilities	$	—	$	329,950	$	7,298	$	337,248

	As of December 31, 2011
	Level 1		Level 2		Level 3		Balance
Assets
Money market funds (1)	$	72,905	$	—	$	—	$	72,905
Federally-sponsored and corporate debt securities (2)	—		583,976		—		583,976
Available-for-sale equity investment	382		—		—		382
Total assets	$	73,287	$	583,976	$	—	$	657,263
Liabilities
Convertible notes maturing in 2016 (3)	$	—	$	292,500	$	—	$	292,500
Contingent consideration (4)	—		—		7,973		7,973
Total liabilities	$	—	$	292,500	$	7,973	$	300,473

(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 principally measured or corroborated by trade data for identical issues or that of comparable securities in which related trading activity is not sufficiently frequent to be considered a Level 1 input. See also Note 5—Marketable Investments—Held-to-Maturity Investments to these consolidated financial statements.

(3)Included in convertible notes on the accompanying consolidated balance sheets. Refer to Note 9—Debt—Convertible Notes Due 2016 for details. The fair value of our 1.0 percent Convertible Senior Notes due September 15, 2016 (2016 Convertible Notes) has been estimated using other observable inputs including the price of our common stock, implied volatility, interest rates and credit spreads among others. Over time, we expect a market for the 2016 Convertible Notes to develop. At that time, we intend to use trade data as the principal basis for measuring fair value.

(4)Included in other liabilities on the accompanying consolidated balance sheets. The fair value of contingent consideration has been estimated using probability weighted discounted cash flow models (DCF). The DCF incorporates Level 3 inputs including estimated discount rates that we believe market participants would consider relevant in pricing and the projected timing and amount of cash flows, which are estimated and developed, in part, based on the requirements specific to each acquisition agreement. We analyze and evaluate these fair value measurements quarterly to determine whether valuation inputs continue to be relevant and appropriate or whether current period developments warrant adjustments to valuation inputs and related measurements. Any increases or decreases in discount rates would have an inverse impact on the value of related fair value measurements, while increases or decreases in expected cash flows would result in corresponding increases or decreases in fair value. As of both September 30, 2012 and December 31, 2011, the cost of debt and weighted average cost of capital used to discount projected cash flows relating to contingent consideration ranged from 8.6 percent to 17.9 percent.

Reconciliation of the beginning and ending balances of Level 3 liabilities

	Contingent Consideration
Balance July 1, 2012—Asset (Liability)	$	(7,841	)
Transfers into Level 3	—
Transfers out of Level 3	—
Total gains/(losses) realized/unrealized
Included in earnings	—
Included in other comprehensive income	(71		)
Purchases	—
Sales	—
Issuances	—
Settlements	614
Balance September 30, 2012—Asset (Liability)	$	(7,298	)
Amount of total gains/(losses) for the three-month period ended September 30, 2012 included in earnings that are attributable to the change in unrealized gains or losses related to outstanding liabilities	$	—

	Contingent Consideration
Balance January 1, 2012—Asset (Liability)	$	(7,973	)
Transfers into Level 3	—
Transfers out of Level 3	—
Total gains/(losses) realized/unrealized
Included in earnings	—
Included in other comprehensive income	61
Purchases	—
Sales	—
Issuances	—
Settlements	614
Balance September 30, 2012—Asset (Liability)	$	(7,298	)
Amount of total gains/(losses) for the nine-month period ended September 30, 2012 included in earnings that are attributable to the change in unrealized gains or losses related to outstanding liabilities	$	—