Cash, Cash Equivalents and Current Marketable Securities

At the end of 2017 and 2016, cash, cash equivalents and current marketable securities were comprised of:



(Dollars in Millions)	2017
	Carrying Amount		Estimated Fair Value	Cash & Cash Equivalents		Current Marketable Securities
Cash	$	2,929	2,929	$	2,929	—
U.S. Gov't Securities⁽¹⁾	—		—	—		—
Other Sovereign Securities⁽¹⁾	279		279	219		60
U.S. Reverse repurchase agreements	4,025		4,025	4,025		—
Other Reverse repurchase agreements	—		—	—		—
Corporate debt securities⁽¹⁾	289		289	244		45
Money market funds	4,288		4,288	4,288		—
Time deposits⁽¹⁾	1,176		1,176	1,175		1
Subtotal	$	12,986	12,986	12,880		106


Gov't Securities	$	4,864	4,864	4,833		31
Other Sovereign Securities	186		186	80		106
Corporate debt securities	260		260	31		229
Subtotal available for sale⁽²⁾	$	5,310	5,310	4,944		366

Total cash, cash equivalents and current marketable securities				$	17,824	472

In 2017, the carrying amount was the same as the estimated fair value.



(Dollars in Millions)	2016
	Carrying Amount		Unrecognized Gain	Unrecognized Loss		Estimated Fair Value	Cash Equivalents		Current Marketable Securities
Cash	$	1,979	—	—		1,979	1,979		—
U.S. Gov't Securities⁽¹⁾	10,832		—	(1	)	10,831	2,249		8,583
Other Sovereign Securities⁽¹⁾	1,299		—	—		1,299	120		1,179
U.S. Reverse repurchase agreements	6,103		—	—		6,103	6,103		—
Other Reverse repurchase agreements	240		—	—		240	240		—
Corporate debt securities⁽¹⁾	754		—	—		754	—		754
Money market funds	7,187		—	—		7,187	7,187		—
Time deposits⁽¹⁾	1,094		—	—		1,094	1,094		—
Subtotal	$	29,488	—	(1	)	29,487	18,972		10,516

			Unrealized Gain	Unrealized Loss
Gov't Securities	$	10,277	5	(51	)	10,231	—		10,231
Other Sovereign Securities	90		—	—		90			90
Corporate debt securities	1,777		1	(12	)	1,766	—		1,766
Equity investments	34		298	—		332			332
Subtotal available for sale⁽²⁾	$	12,178	304	(63	)	12,419	—		12,419

Total cash, cash equivalents and current marketable securities							$	18,972	22,935

⁽¹⁾Held to maturity investments are reported at amortized cost and realized gains or losses are reported in earnings.

⁽²⁾Available for sale securities are reported at fair value with unrealized gains and losses reported net of taxes in other comprehensive income.

Fair value of government securities and obligations and corporate debt securities were estimated using quoted broker prices and significant other observable inputs.

The contractual maturities of the available for sale debt securities at December 31, 2017 are as follows:



(Dollars in Millions)	Cost Basis		Fair Value
Due within one year	$	5,214	5,214
Due after one year through five years	96		96
Due after five years through ten years	—		—
Total debt securities	$	5,310	5,310

The Company invests its excess cash in both deposits with major banks throughout the world and other high-quality money market instruments. The Company has a policy of making investments only with commercial institutions that have at least an investment grade credit rating.