Investments in Marketable Securities (Tables)

3 Months Ended

Sep. 30, 2012

Investments in Marketable Securities [Abstract]

Summary of Investments in Marketable Securities

				September 30, 2012
				Amortized		Unrealized		Unrealized		Fair
(Dollars in millions)				cost		gains		losses		value
Available-for-sale securities:
	Debt instruments:
		U.S. government and agency obligations		$	138	$	4	$	-	$	142
		Municipal debt securities			18		4		-		22
		Certificates of deposit			1,844		1		-		1,845
		Commercial paper			511		-		-		511
		Foreign government debt securities			3		-		-		3
		Corporate debt securities			85		7		-		92
		Mortgage-backed securities:
			U.S. government agency		98		6		-		104
			Non-agency residential		6		1		-		7
			Non-agency commercial		23		1		-		24
		Asset-backed securities			9		-		-		9
	Equity instruments:
		Fixed income mutual funds:
			Short-term sector fund		38		3		-		41
			U.S. government sector fund		293		16		-		309
			Municipal sector fund		19		3		-		22
			Investment grade corporate sector fund		262		52		-		314
			High-yield sector fund		32		7		-		39
			Real return sector fund		276		14		-		290
			Mortgage sector fund		647		-		(2)		645
			Asset-backed securities sector fund		37		7		-		44
			Emerging market sector fund		60		6		-		66
			International sector fund		152		13		-		165
		Equity mutual fund			273		193		-		466
Total investments in marketable securities				$	4,824	$	338	$	(2)	$	5,160

Note 3 – Investments in Marketable Securities (Continued)
					March 31, 2012
				Amortized		Unrealized		Unrealized		Fair
(Dollars in millions)				cost		gains		losses		value
Available-for-sale securities:
	Debt instruments:
		U.S. government and agency obligations		$	108	$	1	$	(1)	$	108
		Municipal debt securities			17		3		-		20
		Certificates of deposit			1,341		-		-		1,341
		Commercial paper			633		-		-		633
		Foreign government debt securities			3		-		-		3
		Corporate debt securities			100		7		-		107
		Mortgage-backed securities:
			U.S. government agency		100		5		-		105
			Non-agency residential		7		1		-		8
			Non-agency commercial		25		1		-		26
		Asset-backed securities			13		-		-		13
	Equity instruments:
		Fixed income mutual funds:
			Short-term sector fund		39		1		-		40
			U.S. government sector fund		319		-		(6)		313
			Municipal sector fund		19		2		-		21
			Investment grade corporate sector fund		261		37		-		298
			High-yield sector fund		31		6		-		37
			Real return sector fund		228		3		-		231
			Mortgage sector fund		651		-		(12)		639
			Asset-backed securities sector fund		37		4		-		41
			Emerging market sector fund		60		2		-		62
			International sector fund		143		19		-		162
		Equity mutual fund			268		183		-		451
Total investments in marketable securities				$	4,403	$	275	$	(19)	$	4,659

Summary of the aging of fair value and gross unrealized losses for AFS securities

Unrealized Losses on Securities
The following table presents the fair value and gross unrealized losses of investments in marketable securities that had been in a continuous unrealized loss position for less than twelve consecutive months. These unrealized losses are recorded in Accumulated Other Comprehensive Income, net of applicable taxes in our Consolidated Statement of Shareholder's Equity:
			Less than 12 months as of
			September 30, 2012				March 31, 2012
			Fair		Unrealized		Fair		Unrealized
(Dollars in millions)			value		losses		value		losses
Available-for-sale securities:
Debt instruments:
	U.S. government and agency
		obligations	$	-	$	-	$	68	$	(1)
Equity instruments:
	U.S. government sector fund			-		-		237		(2)
	Mortgage sector fund			529		(2)		639		(12)
Total investments in marketable
	securities		$	529	$	(2)	$	944	$	(15)

Schedule of realized gains and losses on sales from AFS

			Three Months Ended						Six Months Ended
			September 30,						September 30,
(Dollars in millions)		2012			2011			2012			2011
Available-for-sale securities:
	Realized gains on sales		$	5		$	-		$	9		$	12
	Realized losses on sales		$	1		$	35		$	2		$	35

Summary of Contractual Maturities of Available-for-Sale Securities

		Due in 1 Year or				Due after 1 Year				Due after 5 Years
			Less			through 5 Years				through 10 Years				Due after 10 Years					Total
(Dollars in millions)		Amount		Yield		Amount		Yield		Amount		Yield		Amount		Yield		Amount		Yield
Fair Value of Available-for-Sale Securities:
Debt instruments:
U.S. government and
	agency obligations	$	2	0.05	%	$	49	1.29	%	$	80	1.75	%	$	11	1.84	%	$	142	1.52	%
Municipal debt securities			-	-			3	4.38			1	5.54			18	6.00			22	5.76
Certificates of deposit			1,845	0.67			-	-			-	-			-	-			1,845	0.67
Commercial paper			511	0.18			-	-			-	-			-	-			511	0.18
Foreign government debt
	securities		-	-			3	2.93			-	-			-	-			3	2.93
Corporate debt
	securities		2	4.85			52	4.41			37	5.13			1	7.86			92	4.72
Mortgage-backed securities:
	U.S. government agency		-	-			-	-			5	4.29			99	3.63			104	3.67
	Non-agency residential		-	-			-	-			-	-			7	8.07			7	8.07
	Non-agency commercial		-	-			4	3.45			2	0.86			18	3.91			24	3.62
Asset-backed securities			-	-			1	2.93			3	1.01			5	1.56			9	1.67
Debt instruments total			2,360	0.57			112	2.97			128	2.85			159	3.95			2,759	0.96
Equity instruments:
Fixed income mutual funds																			1,935	4.47
Equity mutual fund																			466	3.53
Equity instruments total			-				-				-				-				2,401	4.29
Total fair value		$	2,360	0.57	%	$	112	2.97	%	$	128	2.85	%	$	159	3.95	%	$	5,160	2.51	%
Total amortized cost		$	2,359			$	107			$	122			$	147			$	4,824