Additional disclosures on cash flow information and non-cash activities (Detail) (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2013		Jun. 30, 2012		Dec. 31, 2012
Cash Flow Noncash Investing And Financing Activities Disclosure Abstract
Transfers Of Loans To Other Real Estate Owned	$ 143,159		$ 151,891
Transfers Of Loans To Other Property	16,009		11,636
Total loans transferred to foreclosed assets	159,168		163,527
Transfer Of Portfolio Loans And Leases To Held For Sale 1	438,640		48,564
Transfer Of Loans Held For Sale To Portfolio Loans 1	21,580		6,633
Noncash Transfer To Securities From Loans Resulting From Securitization	846,327	[1]	525,800	[1]
Trades receivables from brokers and counterparties	158,141		87,774		137,542
Trades Payables To Brokers And Counterparties	72,007		8,587
Recognition of mortgage servicing rights on securitizations or asset transfers	10,152		8,206
Payables Due To Counterparties Related To Early Extinguishment Of Debt	0		376,058
Loans sold to a joint venture in exchange for an acquisition loan and an equity interest in the join venture	$ 194,514		$ 0

[1] Includes loans securitized into trading securities and subsequently sold before quarter end.