Cash and equivalents, marketable securities and short-term investments

12 Months Ended

Dec. 31, 2015

Cash and equivalents, marketable securities and short-term investments

Cash and equivalents and marketable securities and short-term investments

Note 4—Cash and equivalents, marketable securities and short-term investments

Current assets

        Cash and equivalents and marketable securities and short-term investments consisted of the following:

	December 31, 2015
($ in millions)	Cost basis		Gross unrealized gains		Gross unrealized losses			Fair value		Cash and equivalents		Marketable securities and short-term investments
Cash		1,837							1,837		1,837
Time deposits		2,821							2,821		2,717		104
Other short-term investments		231							231				231
Debt securities available-for-sale:
—U.S. government obligations		120		2		(1	)		121		—		121
—Other government obligations		2		—		—			2		—		2
—Corporate		519		1		(1	)		519		11		508
Equity securities available-for-sale		658		9		—			667		—		667
Total		6,188		12		(2	)		6,198		4,565		1,633

	December 31, 2014
($ in millions)	Cost basis		Gross unrealized gains		Gross unrealized losses			Fair value		Cash and equivalents		Marketable securities and short-term investments
Cash		2,218							2,218		2,218
Time deposits		3,340							3,340		3,140		200
Other short-term investments		225							225				225
Debt securities available-for-sale:
—U.S. government obligations		135		2		(1	)		136		—		136
—Other government obligations		2		—		—			2		—		2
—Corporate		734		4		(1	)		737		85		652
Equity securities available-for-sale		98		12		—			110		—		110
Total		6,752		18		(2	)		6,768		5,443		1,325

        Included in Other short-term investments at December 31, 2015 and 2014, are receivables of $224 million and $219 million, respectively, representing reverse repurchase agreements. These collateralized lendings, made to a financial institution, have maturity dates of less than one year.

Non-current assets

        Included in "Other non-current assets" are certain held-to-maturity marketable securities. At December 31, 2015, the amortized cost, gross unrecognized gain and fair value (based on quoted market prices) of these securities were $99 million, $11 million and $110 million, respectively. At December 31, 2014, the amortized cost, gross unrecognized gain and fair value (based on quoted market prices) of these securities were $95 million, $14 million and $109 million, respectively. These securities are pledged as security for certain outstanding deposit liabilities and the funds received at the respective maturity dates of the securities will only be available to the Company for repayment of these obligations.

Gains, losses and contractual maturities

        Gross realized gains (reclassified from accumulated other comprehensive loss to income) on available-for-sale securities totaled $1 million, $2 million and $10 million in 2015, 2014 and 2013, respectively. Gross realized losses (reclassified from accumulated other comprehensive loss to income) on available-for-sale securities totaled $2 million and $23 million in 2015 and 2014, respectively, and were not significant in 2013. Such gains and losses were included in "Interest and other finance expense".

        In 2015, 2014 and 2013, other-than-temporary impairments recognized on available-for-sale equity securities were not significant.

        At December 31, 2015, 2014 and 2013, gross unrealized losses on available-for-sale securities that have been in a continuous unrealized loss position were not significant and the Company does not intend and does not expect to be required to sell these securities before the recovery of their amortized cost.

        There were no sales of held-to-maturity securities in 2015, 2014 and 2013.

        Contractual maturities of debt securities consisted of the following:

	December 31, 2015
	Available-for-sale				Held-to-maturity
($ in millions)	Cost basis		Fair value		Cost basis		Fair value
Less than one year		430		430		—		—
One to five years		160		161		99		110
Six to ten years		51		51		—		—
Total		641		642		99		110

        At December 31, 2015 and 2014, the Company pledged $92 million and $95 million, respectively, of available-for-sale marketable securities as collateral for issued letters of credit and other security arrangements.