Mortgage Servicing Assets (Tables)

3 Months Ended

Mar. 31, 2012

Mortgage Servicing Assets [Abstract]

Changes in the carrying amount of mortgage servicing assets

	Three months ended March 31,
in millions	2012		2011
Balance at beginning of period	$	173	$	196
Servicing retained from loan sales		8		3
Purchases		16		—
Amortization		(14)		(17)
Balance at end of period	$	183	$	182
Fair value at end of period	$	226	$	232