Available-for-sale investments as of December 31, 2011 and December 25, 2010 were as follows:

	2011								2010
			Gross		Gross						Gross		Gross
	Adjusted		Unrealized		Unrealized		Fair		Adjusted		Unrealized		Unrealized		Fair
(In Millions)	Cost		Gains		Losses		Value		Cost		Gains		Losses		Value
Government bonds	$	4,131	$	—	$	(4)	$	4,127	$	10,075	$	9	$	(5)	$	10,079
Commercial paper		3,820		—		(3)		3,817		5,312		—		—		5,312
Bank deposits		1,046		1		(1)		1,046		1,550		1		—		1,551
Corporate bonds		892		14		(9)		897		2,250		9		(4)		2,255
Marketable equity securities		189		385		(12)		562		380		629		(1)		1,008
Money market fund deposits		546		—		—		546		34		—		—		34
Asset-backed securities		48		—		(12)		36		76		—		(9)		67
Total available-for-sale
investments	$	10,672	$	400	$	(41)	$	11,031	$	19,677	$	648	$	(19)	$	20,306

In the preceding table, government bonds include bonds issued or deemed to be guaranteed by government entities. Government bonds include instruments such as U.S. Treasury securities, non-U.S. government bonds, and U.S. agency securities as of December 31, 2011 and December 25, 2010. Bank deposits were primarily issued by institutions outside the U.S. as of December 31, 2011 and December 25, 2010.

The amortized cost and fair value of available-for-sale debt investments as of December 31, 2011, by contractual maturity, were as follows:

(In Millions)	Cost		Fair Value
Due in 1 year or less	$	9,033	$	9,034
Due in 1–2 years		626		626
Due in 2–5 years		226		224
Due after 5 years		4		3
Instruments not due at a single maturity date		594		582
Total	$	10,483	$	10,469

Instruments not due at a single maturity date in the preceding table include asset-backed securities and money market fund deposits.

We sold available-for-sale investments for proceeds of $9.1 billion in 2011 ($475 million in 2010 and $192 million in 2009). Substantially all of the proceeds in 2011 were from debt investments that were primarily used to fund our acquisition of McAfee. The gross realized gains on sales of available-for-sale investments were $268 million in 2011 ($160 million in 2010 and $43 million in 2009) and were primarily related to our sales of marketable equity securities. Gains on third-party merger transactions during 2011 were insignificant (insignificant in 2010 and $56 million in 2009).

Impairment charges recognized on available-for-sale investments were $73 million in 2011 (insignificant in 2010 and 2009). Gross realized losses recognized on available-for-sale investments were insignificant in 2011 ($13 million in 2010 and $64 million in 2009). We had previously recognized other-than-temporary impairments totaling $34 million during 2008 and 2009 on the investments that were sold in 2009.