Financial Instruments

We invest our excess cash in a variety of marketable securities, which are all classified as available-for-sale. The following summarizes our cash and cash equivalents, restricted cash and cash equivalents and marketable securities by financial instrument category as of the respective period ends:



	November 30, 2016
($ in thousands)	Amortized Cost		Unrealized Gains		Unrealized Losses			Fair Value		Cash and Cash Equivalents⁽¹⁾		Current Marketable Securities		Noncurrent Marketable Securities
Cash	$	470,237	$	—	$	—		$	470,237	$	470,237	$	—	$	—
Level 1:
Money market funds	137,424		—		—			137,424		137,424		—		—
Level 2:
Corporate bonds	38,588		15		(61		)	38,542		—		33,382		5,160
Tax-exempt municipal bonds	56,955		3		(63		)	56,895		7,494		47,668		1,733
Other	63,330		12		(10		)	63,332		26,990		36,342		—
Total	$	766,534	$	30	$	(134	)	$	766,430	$	642,145	$	117,392	$	6,893



	August 31, 2016
($ in thousands)	Amortized Cost		Unrealized Gains		Unrealized Losses			Fair Value		Cash and Cash Equivalents⁽¹⁾		Current Marketable Securities		Noncurrent Marketable Securities
Cash	$	527,662	$	—	$	—		$	527,662	$	527,662	$	—	$	—
Level 1:
Money market funds	66,265		—		—			66,265		66,265		—		—
Level 2:
Corporate bonds	91,426		33		(56		)	91,403		—		79,055		12,348
Tax-exempt municipal bonds	75,696		26		(13		)	75,709		100		70,697		4,912
Other	61,801		12		(14		)	61,799		12,167		48,134		1,498
Total	$	822,850	$	71	$	(83	)	$	822,838	$	606,194	$	197,886	$	18,758

⁽¹⁾ Cash and cash equivalents includes restricted cash and cash equivalents.

We measure our financial instruments at fair value on a recurring basis as follows:


•	Money market funds - We use Level 1 inputs that primarily consist of real-time quotes for transactions in active exchange markets involving identical assets.


•	Other financial instruments - We use a market approach with Level 2 observable inputs for all other securities. The Level 2 inputs include quoted prices for similar assets in active markets, or quoted prices for identical or similar assets in markets that are not active.

Our marketable securities have maturities that occur within two years. We may sell certain of our marketable securities prior to their stated maturities for strategic reasons including, but not limited to, investment yield and credit risk management. We have not recognized significant gains or losses related to such sales.