Cash and Cash Equivalents (Detail) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014		Dec. 31, 2013		Jun. 30, 2013	Dec. 31, 2012
Cash and Cash Equivalents [Abstract]
Cash and due from banks	$ 2,589,946	[1]	$ 1,349,688	[1]
Securities purchased under agreements to resell	53,764	[2]	172,989	[2]
Other short-term investment securities	6,121		16,102
Total cash and cash equivalents	$ 2,649,831		$ 1,538,779		$ 873,251	$ 1,008,983

[1] At June 30, 2014 and December 31, 2013, $1.7 billion and $715 million, respectively, of our cash and due from banks was deposited at the Federal Reserve Bank and was earning interest at the Federal Funds target rate, and interest-earning deposits in other financial institutions were $443 million and $300 million, respectively.

[2] At June 30, 2014 and December 31, 2013, securities purchased under agreements to resell were collateralized by U.S. Treasury securities and U.S. agency securities with aggregate fair values of $55 million and $176 million, respectively. None of these securities received as collateral were sold or repledged as of June 30, 2014 or December 31, 2013.