Fair Value Measurements of Assets and Liabilities

3 Months Ended

Mar. 31, 2013

Fair Value Disclosures [Abstract]

Fair Value Measurements of Assets and Liabilities

FAIR VALUE MEASUREMENTS OF ASSETS AND LIABILITIES

Factors used in determining the fair value of our financial assets and liabilities are summarized into three broad categories:

• Level 1 – quoted prices in active markets for identical securities as of the reporting date;

• Level 2 – other significant directly or indirectly observable inputs, including quoted prices for similar securities, interest rates, prepayment speeds and credit risk; and

• Level 3 – significant inputs that are generally less observable than objective sources, including our own assumptions in determining fair value.

The factors or methodology used for valuing securities are not necessarily an indication of the risk associated with investing in those securities.

Following are the disclosures related to the fair value of our financial assets and (liabilities) (in thousands):

March 31, 2013	Level 1		Level 2			Level 3		Total
Available for sale marketable securities:
U.S. treasury notes	$	53,034	$	—		$	—	$	53,034
Agency bonds	—		35,608			—		35,608
Commercial paper	—		9,998			—		9,998
Certificates of deposit	—		6,271			—		6,271
Municipal bonds	—		16,958			—		16,958
Trading securities:
Equity securities – mutual funds	3,911		—			—		3,911
Derivative contracts, net	—		(2,332		)	—		(2,332		)
Total	$	56,945	$	66,503		$	—	$	123,448

December 31, 2012	Level 1		Level 2		Level 3		Total
Available for sale marketable securities:
U.S. treasury notes	$	60,786	$	—	$	—	$	60,786
Agency bonds	—		31,157		—		31,157
Commercial paper	—		5,000		—		5,000
Certificates of deposit	—		5,494		—		5,494
Municipal bonds	—		3,228		—		3,228
Trading securities:
Equity securities – mutual funds	3,046		—		—		3,046
Derivative contracts, net	—		1,655		—		1,655
Total	$	63,832	$	46,534	$	—	$	110,366

Agency bonds are securities backed by U.S. government-sponsored entities.

We use an income approach to value the assets and liabilities for outstanding derivative contracts using current market information as of the reporting date, such as spot rates, interest rate differentials and implied volatility.

There were no transfers between fair value categories or changes to our valuation techniques during thethirteen week period endedMarch 31, 2013.

We believe the carrying amounts of cash and cash equivalents, accounts receivable, accounts payable and other current liabilities are a reasonable approximation of the fair value of those financial instruments because of the nature of the underlying transactions and the short-term maturities involved.

Our fixed rate convertible debt outstanding was as follows (in thousands):

	March 31, 2013
Fixed rate convertible debt on balance sheet	$	89,010
Fair value of fixed rate convertible debt	195,749

The fair value of our fixed rate convertible debt is based on open market trades and is classified as Level 2 in the fair value hierarchy.