Fair Value of Financial Instruments (Tables)

3 Months Ended

Mar. 31, 2012

Fair Value of Financial Instruments

Financial assets and liabilities measured at fair value on a recurring basis

	Fair Value Measurements at March 31, 2012 Using
Description	Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Total
Assets:
Cash Equivalents:
Money market funds	$	42,887	$	—	$	—	$	42,887
U.S. Treasury bills	11,900		—		—		11,900
Total cash equivalents	$	54,787	$	—	$	—	$	54,787
Short-term Investments:
Corporate bonds	$	—	$	83,599	$	—	$	83,599
Municipal bonds	—		67,339		—		67,339
Variable-rate demand notes	—		48,310		—		48,310
U.S. government bonds	12,639		—		—		12,639
Asset-backed securities	—		10,042		—		10,042
U.S. government agency	—		5,902		—		5,902
U.S. Treasury bills	5,349		—		—		5,349
International government bonds	—		2,119		—		2,119
Total short-term investments	$	17,988	$	217,311	$	—	$	235,299
Long-term Investments:
Auction rate securities	$	—	$	—	$	17,729	$	17,729
Total long-term investments	$	—	$	—	$	17,729	$	17,729
Total	$	72,775	$	217,311	$	17,729	$	307,815
Liabilities:
Derivative instruments	$	—	$	1,696	$	—	$	1,696
Total	$	—	$	1,696	$	—	$	1,696

	Fair Value Measurements at December 31, 2011 Using
Description	Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Total
Assets:
Cash Equivalents:
Money market funds	$	50,851	$	—	$	—	$	50,851
Total cash equivalents	$	50,851	$	—	$	—	$	50,851
Short-term Investments:
Corporate bonds	$	—	$	75,060	$	—	$	75,060
Municipal bonds	—		56,984		—		56,984
Variable-rate demand notes	—		41,280		—		41,280
U.S. government agency	—		19,836		—		19,836
U.S. Treasury bills	8,600		—		—		8,600
Asset-backed securities	—		5,739		—		5,739
U.S. government bonds	2,507		—		—		2,507
Certificates of deposit	—		1,570		—		1,570
International government bonds	—		950		—		950
Total short-term investments	$	11,107	$	201,419	$	—	$	212,526
Long-term Investments:
Auction rate securities	$	—	$	—	$	17,477	$	17,477
Total long-term investments	$	—	$	—	$	17,477	$	17,477
Total	$	61,958	$	201,419	$	17,477	$	280,854
Liabilities:
Derivative instruments	$	—	$	1,998	$	—	$	1,998
Contingent consideration	—		—		876		876
Total	$	—	$	1,998	$	876	$	2,874

Summary of quantitative information about level 3 fair value measurements

Description	Fair Value at March 31, 2012 (000s)		Valuation Technique	Unobservable Input	Weighted Average
Auction rate securities	$	17,729	Discounted cash flow	Estimated yield	2.0%
				Expected holding periods	10 years
				Estimated discount rate	3.4%

Summary of activity in Level 3 financial instruments

Assets	Auction Rate Securities
Balance at December 31, 2011	$	17,477
Settlements	(50		)
Unrealized gains	302
Balance at March 31, 2012	$	17,729

Liabilities	Contingent Consideration (1)
Balance at December 31, 2011	$	876
Gain recognized in earnings (2)	(876		)
Balance at March 31, 2012	$	—
Net gain for period included in earnings attributable to contingent consideration held at March 31, 2012:	$	876

(1)

In connection with the acquisition of ChipSensors, the Company recorded contingent consideration based upon the achievement of certain milestone goals. Changes to the fair value of contingent consideration due to changes in assumptions used in preparing the discounted cash flow model are recorded in selling, general and administrative expenses in the Consolidated Statement of Operations. Changes resulting from foreign currency remeasurement adjustments to the contingent consideration liability are recorded in other income (expense), net.

(2)

The Company reduced the estimated fair value of contingent consideration because certain milestone goals were either not achieved or are less likely to be achieved.