Available-for-Sale Securities

6 Months Ended

Dec. 31, 2016

Investments, Debt and Equity Securities [Abstract]

Available-for-Sale Securities

5. Available-for-Sale Securities

We invest in marketable securities, which are classified as available-for-sale and are carried at fair value in the condensed consolidated balance sheets. We held the following investments in marketable securities at fair value at:

(in millions)	December 31, 2016		June 30, 2016
Current available-for-sale securities:
Treasury bills	$	—	$	3
International bonds	3		2
Corporate bonds	59		58
U.S. agency bonds	11		6
Asset-backed securities	26		28
International equity securities	1		2
U.S. agency mortgage-backed securities	10		14
Total current available-for-sale securities	110		113
Long-term available-for-sale securities:
Treasury bills	24		10
International bonds	3		1
Corporate bonds	29		36
U.S. agency bonds	—		9
Asset-backed securities	16		17
U.S. agency mortgage-backed securities	19		14
Total long-term available-for-sale securities	91		87
Total available-for-sale securities	$	201	$	200

Gross unrealized gains and losses on available-for-sale securities were immaterial at both December 31, 2016 and June 30, 2016. During the six months ended December 31, 2016 and 2015, gross realized gains and losses on available-for-sale securities were immaterial and we did not recognize any other-than-temporary impairments. At December 31, 2016, the weighted-average effective maturity of our current and long-term marketable securities was approximately 6 months and 16 months, respectively.