Marketable securities and securities investments

12 Months Ended

Mar. 31, 2011

Marketable securities and securities investments [Abstract]

Marketable securities and securities investments

7.   Marketable securities and securities investments

Marketable securities and securities investments, mainly included in the Financial Services segment, are comprised of debt and equity securities of which the aggregate cost, gross unrealized gains and losses and fair value pertaining to available-for-sale securities and held-to-maturity securities are as follows:

	Yen in millions
	March 31, 2010									March 31, 2011
			Gross		Gross							Gross		Gross
			unrealized		unrealized							unrealized		unrealized
	Cost		gains		losses			Fair value		Cost		gains		losses			Fair value
Available-for-sale:
Debt securities:
Japanese national government bonds		1,264,725		29,496		(3,397	)		1,290,824		1,124,704		24,032		(4,971	)		1,143,765
Japanese local government bonds		27,750		1,097		(5	)		28,842		22,845		184		(64	)		22,965
Japanese corporate bonds		360,554		3,773		(106	)		364,221		332,567		1,511		(440	)		333,638
Foreign corporate bonds		281,003		4,818		(6,492	)		279,329		332,616		4,872		(11,368	)		326,120
Other		11,141		83		(123	)		11,101		7,941		109		(117	)		7,933
		1,945,173		39,267		(10,123	)		1,974,317		1,820,673		30,708		(16,960	)		1,834,421
Equity securities		99,753		74,430		(3,437	)		170,746		84,417		69,073		(3,447	)		150,043
Held-to-maturity Securities:
Japanese national government bonds		2,248,230		3,318		(30,740	)		2,220,808		2,902,342		22,420		(48,149	)		2,876,613
Japanese local government bonds		23,617		346		—			23,963		18,912		218		(2	)		19,128
Japanese corporate bonds		32,041		150		(321	)		31,870		32,349		158		(67	)		32,440
Foreign corporate bonds		50,831		18		(7	)		50,842		47,330		13		(3	)		47,340
		2,354,719		3,832		(31,068	)		2,327,483		3,000,933		22,809		(48,221	)		2,975,521
Total		4,399,645		117,529		(44,628	)		4,472,546		4,906,023		122,590		(68,628	)		4,959,985

The following table presents the cost and fair value of debt securities classified as available-for-sale securities and held-to-maturity securities by contractual maturity:

	Yen in millions
	March 31, 2011
	Available-for-sale securities				Held-to-maturity securities
	Cost		Fair Value		Cost		Fair Value
Due in one year or less		260,669		253,678		17,251		17,328
Due after one year through five years		527,179		530,151		39,086		39,359
Due after five year through ten years		232,848		237,851		9,025		9,561
Due after ten years		799,977		812,741		2,935,571		2,909,273
Total		1,820,673		1,834,421		3,000,933		2,975,521

Proceeds from sales of available-for-sale securities were 1,165,451 million yen, 785,698 million yen and 532,619 million yen for the fiscal years ended March 31, 2009, 2010 and 2011, respectively. On these sales, gross realized gains were 41,860 million yen, 39,622 million yen and 38,654 million yen and gross realized losses were 30,554 million yen, 37,537 million yen and 2,014 million yen, respectively.

Marketable securities classified as trading securities at March 31, 2010 and 2011 were 353,353 million yen and 375,802 million yen, respectively, which consist of debt and equity securities.

In the ordinary course of business, Sony maintains long-term investment securities, included in securities investments and other, issued by a number of non-public companies. The aggregate carrying amounts of the investments in non-public companies at March 31, 2010 and 2011, totaled 70,705 million yen and 67,376 million yen, respectively. Non-public equity investments are primarily valued at cost as fair value is not readily determinable.

With respect to trading securities, primarily in the Financial Services segment, Sony recorded net unrealized losses of 79,476 million yen for the fiscal year ended March 31, 2009, net unrealized gains of 50,992 million yen for the fiscal year ended March 31, 2010 and net realized losses of 10,768 million yen for the fiscal year ended March 31, 2011. Changes in the fair value of trading securities are primarily recognized in financial services revenue in the consolidated statements of income.

The following tables present the gross unrealized losses on, and fair value of, Sony’s investment securities with unrealized losses, aggregated by investment category and the length of time that individual investment securities have been in a continuous unrealized loss position, at March 31, 2010 and 2011.

	Yen in millions
	March 31, 2010
	Less than 12 months					12 months or More					Total
			Unrealized					Unrealized					Unrealized
	Fair value		losses			Fair value		losses			Fair value		losses
Available-for-sale:
Debt securities:
Japanese national government bonds		139,613		(891	)		53,704		(2,506	)		193,317		(3,397	)
Japanese local government bonds		1,887		(5	)		—		—			1,887		(5	)
Japanese corporate bonds		48,151		(84	)		1,965		(22	)		50,116		(106	)
Foreign corporate bonds		46,764		(378	)		88,258		(6,114	)		135,022		(6,492	)
Other		6,441		(123	)		—		—			6,441		(123	)
		242,856		(1,481	)		143,927		(8,642	)		386,783		(10,123	)
Equity securities		10,069		(934	)		11,486		(2,503	)		21,555		(3,437	)
Held-to-maturity
Securities:
Japanese national government bonds		1,496,584		(11,066	)		465,416		(19,674	)		1,962,000		(30,740	)
Japanese local government bonds		100		—			—		—			100		—
Japanese corporate bonds		19,828		(314	)		95		(7	)		19,923		(321	)
Foreign corporate bonds		88		(4	)		305		(3	)		393		(7	)
		1,516,600		(11,384	)		465,816		(19,684	)		1,982,416		(31,068	)
Total		1,769,525		(13,799	)		621,229		(30,829	)		2,390,754		(44,628	)

	Yen in millions
	March 31, 2011
	Less than 12 months					12 months or More					Total
			Unrealized					Unrealized					Unrealized
	Fair value		losses			Fair value		losses			Fair value		losses
Available-for-sale:
Debt securities:
Japanese national government bonds		223,686		(3,230	)		54,477		(1,741	)		278,163		(4,971	)
Japanese local government bonds		12,434		(64	)		—		—			12,434		(64	)
Japanese corporate bonds		130,318		(440	)		—		—			130,318		(440	)
Foreign corporate bonds		126,484		(7,184	)		30,277		(4,184	)		156,761		(11,368	)
Other		2,882		(117	)		—		—			2,882		(117	)
		495,804		(11,035	)		84,754		(5,925	)		580,558		(16,960	)
Equity securities		36,391		(3,353	)		386		(94	)		36,777		(3,447	)
Held-to-maturity
Securities:
Japanese national government bonds		1,812,196		(48,149	)		—		—			1,812,196		(48,149	)
Japanese local government bonds		531		(2	)		—		—			531		(2	)
Japanese corporate bonds		20,788		(67	)		—		—			20,788		(67	)
Foreign corporate bonds		194		(3	)		—		—			194		(3	)
		1,833,709		(48,221	)		—		—			1,833,709		(48,221	)
Total		2,365,904		(62,609	)		85,140		(6,019	)		2,451,044		(68,628	)

For the fiscal years ended March 31, 2009, 2010 and 2011, total realized impairment losses were 45,644 million yen, 5,508 million yen and 9,763 million yen, respectively.

At March 31, 2011, Sony determined that the decline in value for securities with unrealized losses shown in the above table is not other-than-temporary in nature.