Available-For-Sale Securities (Tables)

12 Months Ended

Sep. 30, 2015

Investments, Debt and Equity Securities [Abstract]

Interest-Bearing Investments in Available-for-Sale Securities

Available-for-sale securities consist of the following interest-bearing investments:


	As of September 30, 2015
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Fair Value
Money market funds	$	470,286	$	—	$	—	$	470,286
U.S. government treasuries		117,235		217		—		117,452
Corporate bonds		101,613		123		133		101,603
U.S. agency securities		45,105		76		—		45,181
Asset backed obligations		29,195		20		—		29,215
Commercial paper and certificates of deposit		27,502		—		—		27,502
Supranational and sovereign debt		10,423		20		—		10,443

Total(1)	$	801,359	$	456	$	133	$	801,682

(1)

Available-for-sale securities with maturities longer than 90 days from the date of acquisition were classified as short term interest-bearing investments and available-for-sale securities with maturities of 90 days or less from the date of acquisition were included in cash and cash equivalents on the Company’s balance sheet. As of September 30, 2015, $318,439 of securities were classified as short term interest-bearing investments and $483,243 of securities were classified as cash and cash equivalents.


	As of September 30, 2014
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Fair Value
Money market funds	$	649,745	$	—	$	—	$	649,745
U.S. government treasuries		118,652		88		32		118,708
Corporate bonds		102,387		152		119		102,420
U.S. agency securities		41,658		—		9		41,649
Asset backed obligations		29,160		—		65		29,095
Commercial paper and certificates of deposit		28,509		—		—		28,509
Supranational and sovereign debt		5,804		—		5		5,799
Government-guaranteed debt		1,185		2		—		1,187
Mortgages		569		—		42		527

Total(2)	$	977,669	$	242	$	272	$	977,639

(2)	As of September 30, 2014, $321,196 of securities were classified as short term interest-bearing investments and $656,443 of securities were classified as cash and cash equivalents.

Available-for-Sale Securities Debt Maturities Market Value

As of September 30, 2015, the Company’s available-for-sale securities had the following maturity dates:


	Market Value
Due within one year	$	596,762
1 to 2 years		118,196
2 to 3 years		67,140
3 to 4 years		13,209
Thereafter		6,375

	$	801,682