Cash, Cash Equivalents and Short-Term Investments (Tables)

6 Months Ended

May 31, 2019

Cash, Cash Equivalents, and Short-term Investments [Abstract]

Cash Cash Equivalents and Short term Investments

Cash, cash equivalents and short-term investments consisted of the following as of May 31, 2019 (in thousands):



	Amortized Cost		Unrealized Gains		Unrealized Losses			Estimated Fair Value
Current assets:
Cash	$	400,023	$	—	$	—		$	400,023
Cash equivalents:
Corporate debt securities	144,563		—		(8		)	144,555
Money market mutual funds	1,474,933		—		—			1,474,933
Municipal securities	1,000		—		—			1,000
Time deposits	57,400		—		—			57,400
U.S. agency securities	4,999		—		—			4,999
Total cash equivalents	1,682,895		—		(8		)	1,682,887
Total cash and cash equivalents	2,082,918		—		(8		)	2,082,910
Short-term fixed income securities:
Asset-backed securities	61,145		59		(80		)	61,124
Corporate debt securities	1,314,844		804		(3,616		)	1,312,032
Foreign government securities	2,399		—		(6		)	2,393
Municipal securities	20,499		47		(26		)	20,520
Total short-term investments	1,398,887		910		(3,728		)	1,396,069
Total cash, cash equivalents and short-term investments	$	3,481,805	$	910	$	(3,736	)	$	3,478,979

Cash, cash equivalents and short-term investments consisted of the following as of November 30, 2018 (in thousands):



	Amortized Cost		Unrealized Gains		Unrealized Losses			Estimated Fair Value
Current assets:
Cash	$	368,564	$	—	$	—		$	368,564
Cash equivalents:
Money market mutual funds	1,234,188		—		—			1,234,188
Time deposits	40,023		—		—			40,023
Total cash equivalents	1,274,211		—		—			1,274,211
Total cash and cash equivalents	1,642,775		—		—			1,642,775
Short-term fixed income securities:
Asset-backed securities	41,875		—		(367		)	41,508
Corporate debt securities	1,546,860		44		(24,696		)	1,522,208
Foreign government securities	4,179		—		(24		)	4,155
Municipal securities	18,601		1		(286		)	18,316
Total short-term investments	1,611,515		45		(25,373		)	1,586,187
Total cash, cash equivalents and short-term investments	$	3,254,290	$	45	$	(25,373	)	$	3,228,962

Continuous Unrealized Loss Position Less Than Twelve Months Related to Available-for-Sale Securities

The following table summarizes the fair value and gross unrealized losses related to available-for-sale securities, aggregated by investment category, that have been in an unrealized loss position for less than twelve months, as of May 31, 2019 and November 30, 2018 (in thousands):



	2019					2018
	Fair Value		Gross Unrealized Losses			Fair Value		Gross Unrealized Losses
Corporate debt securities	$	178,253	$	(43	)	$	538,109	$	(7,966	)
Asset-backed securities	5,501		—			6,696		(54		)
Municipal securities	1,942		—			6,599		(81		)
Total	$	185,696	$	(43	)	$	551,404	$	(8,101	)

There were 58 securities and 369 securities in an unrealized loss position for less than twelve months at May 31, 2019 and at November 30, 2018, respectively.

Continuous Unrealized Loss Position Twelve Months or Longer Related to Available-for-Sale-Securities

The following table summarizes the fair value and gross unrealized losses related to available-for-sale securities, aggregated by investment category, that were in a continuous unrealized loss position for more than twelve months, as of May 31, 2019 and November 30, 2018 (in thousands):



	2019					2018
	Fair Value		Gross Unrealized Losses			Fair Value		Gross Unrealized Losses
Corporate debt securities	$	940,760	$	(3,581	)	$	969,701	$	(16,730	)
Asset-backed securities	24,847		(80		)	34,812		(313		)
Municipal securities	8,725		(26		)	11,532		(205		)
Foreign government securities	2,393		(6		)	4,154		(24		)
Total	$	976,725	$	(3,693	)	$	1,020,199	$	(17,272	)

There were 547 securities and 577 securities in an unrealized loss position for more than twelve months at May 31, 2019 and at November 30, 2018, respectively.

Cost and Estimated Fair Value of Debt Securities

The following table summarizes the cost and estimated fair value of short-term fixed income securities classified as short-term investments based on stated effective maturities as of May 31, 2019 (in thousands):



	Amortized Cost		Estimated Fair Value
Due within one year	$	612,044	$	610,831
Due between one and two years	587,933		586,542
Due between two and three years	136,276		136,058
Due after three years	62,634		62,638
Total	$	1,398,887	$	1,396,069