Marketable securities and securities investments (Tables)

12 Months Ended

Mar. 31, 2013

Debt and Equity Securities of Aggregate Cost, Gross Unrealized Gains and Losses and Fair Value Pertaining to Available-for-Sale Securities and Held-to-Maturity Securities

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, 2012									March 31, 2013
	Cost		Gross unrealized gains		Gross unrealized losses			Fair value		Cost		Gross unrealized gains		Gross unrealized losses			Fair value
Available-for-sale:
Debt securities:
Japanese national government bonds		1,036,946		55,384		(879	)		1,091,451		1,106,265		114,806		(463	)		1,220,608
Japanese local government bonds		33,513		163		(1	)		33,675		66,553		643		(1	)		67,195
Japanese corporate bonds		293,885		1,489		(224	)		295,150		210,519		1,715		(70	)		212,164
Foreign corporate bonds		377,609		4,705		(7,063	)		375,251		425,892		17,502		(620	)		442,774
Other		22,383		1,548		(6	)		23,925		20,607		4,431		(2	)		25,036
		1,764,336		63,289		(8,173	)		1,819,452		1,829,836		139,097		(1,156	)		1,967,777
Equity securities		60,694		53,016		(1,513	)		112,197		89,079		44,443		(997	)		132,525
Held-to-maturity Securities:
Japanese national government bonds		3,404,069		157,740		(4,499	)		3,557,310		3,876,600		545,188		—			4,421,788
Japanese local government bonds		12,592		277		—			12,869		7,195		432		—			7,627
Japanese corporate bonds		31,379		1,501		—			32,880		28,918		3,571		—			32,489
Foreign corporate bonds		46,441		10		—			46,451		52,738		20		—			52,758
		3,494,481		159,528		(4,499	)		3,649,510		3,965,451		549,211		—			4,514,662
Total		5,319,511		275,833		(14,185	)		5,581,159		5,884,366		732,751		(2,153	)		6,614,964

Cost and Fair Value of Debt Securities Classified as Available-for-Sale Securities and Held-to-Maturity Securities by Contractual Maturity

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, 2013
	Available-for-sale securities				Held-to-maturity securities
	Cost		Fair Value		Cost		Fair Value
Due in one year or less		160,018		167,853		5,060		5,068
Due after one year through five years		526,540		536,129		20,124		20,828
Due after five years through ten years		258,717		268,767		31,206		33,720
Due after ten years		884,561		995,028		3,909,061		4,455,046
Total		1,829,836		1,967,777		3,965,451		4,514,662

Gross Unrealized Losses and Fair Value of Securities with Unrealized Losses, Aggregated by Investment Category and Length of Time of Continuous Unrealized Loss Position

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, 2012 and 2013.

	Yen in millions
	March 31, 2012
	Less than 12 months					12 months or more					Total
	Fair value		Unrealized losses			Fair value		Unrealized losses			Fair value		Unrealized losses
Available-for-sale:
Debt securities:
Japanese national government bonds		55,450		(877	)		3,048		(2	)		58,498		(879	)
Japanese local government bonds		2,364		(1	)		—		—			2,364		(1	)
Japanese corporate bonds		1,034		(196	)		25,243		(28	)		26,277		(224	)
Foreign corporate bonds		68,277		(6,065	)		83,650		(998	)		151,927		(7,063	)
Other		335		(6	)		—		—			335		(6	)
		127,460		(7,145	)		111,941		(1,028	)		239,401		(8,173	)
Equity securities		4,337		(318	)		16,826		(1,195	)		21,163		(1,513	)
Held-to-maturity Securities:
Japanese national government bonds		—		—			333,702		(4,499	)		333,702		(4,499	)
Japanese local government bonds		70		(0	)		—		—			70		(0	)
Japanese corporate bonds		—		—			—		—			—		—
Foreign corporate bonds		—		—			—		—			—		—
		70		(0	)		333,702		(4,499	)		333,772		(4,499	)
Total		131,867		(7,463	)		462,469		(6,722	)		594,336		(14,185	)

	Yen in millions
	March 31, 2013
	Less than 12 months					12 months or more					Total
	Fair value		Unrealized losses			Fair value		Unrealized losses			Fair value		Unrealized losses
Available-for-sale:
Debt securities:
Japanese national government bonds		3,383		(0	)		46,796		(463	)		50,179		(463	)
Japanese local government bonds		592		(1	)		—		—			592		(1	)
Japanese corporate bonds		4,731		(7	)		5,271		(63	)		10,002		(70	)
Foreign corporate bonds		28,133		(83	)		19,228		(537	)		47,361		(620	)
Other		61		(0	)		144		(2	)		205		(2	)
		36,900		(91	)		71,439		(1,065	)		108,339		(1,156	)
Equity securities		10,458		(933	)		75		(64	)		10,533		(997	)
Held-to-maturity Securities:
Japanese national government bonds		—		—			—		—			—		—
Japanese local government bonds		—		—			—		—			—		—
Japanese corporate bonds		—		—			—		—			—		—
Foreign corporate bonds		—		—			—		—			—		—
		—		—			—		—			—		—
Total		47,358		(1,024	)		71,514		(1,129	)		118,872		(2,153	)