Cash and Cash Equivalents (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010	Dec. 31, 2009
Cash and Cash Equivalents [Abstract]
Cash and due from banks	$ 752,056	[1]	$ 852,010	[1]
Securities purchased under agreements to resell	133,357	[2]	175,553	[2]
Other short-term investment securities	123,570		87,385
Total cash and cash equivalents	$ 1,008,983		$ 1,114,948		$ 3,076,432	$ 3,512,853

[1] At December 31, 2012 and 2011, $72 million and $100 million, respectively, of our cash and due from banks was deposited at the FRB and was earning interest at the Federal Funds target rate, and interest-earning deposits in other financial institutions were $283 million and $372 million, respectively.

[2] At December 31, 2012 and 2011, securities purchased under agreements to resell were collateralized by U.S. treasury securities and U.S. agency securities with aggregate fair values of $136 million and $179 million, respectively. None of these securities received as collateral were sold or repledged as of December 31, 2012 and 2011.