The components of accumulated other comprehensive income, net of tax, at the end of each period, as well as the activity, were as follows:

			Other
	Dec. 31,		Comprehensive		March 31,
(In Millions)	2011		Income		2012
Accumulated net unrealized holding gain (loss) on available-for-sale investments	$	231	$	166	$	397
Accumulated net deferred tax asset valuation allowance		104		—		104
Accumulated net unrealized holding gain (loss) on derivatives		8		(34)		(26)
Accumulated net prior service costs		(32)		1		(31)
Accumulated net actuarial losses		(950)		16		(934)
Accumulated net foreign currency translation adjustment		(142)		28		(114)
Total accumulated other comprehensive income (loss)	$	(781)	$	177	$	(604)