Note Supplemental disclosure on the consolidated statments of cash flows (Additional disclosures on cash flow information and non-cash activities) (Detail) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016
Cash Flow Noncash Investing And Financing Activities Disclosure Abstract
Transfers Of Loans To Other Real Estate Owned		$ 32,597	$ 26,919
Transfers Of Loans To Other Property		8,956	7,693
Total loans transferred to foreclosed assets		41,553	34,612
Financed sales of other real estate assets		2,904	3,943
Financed sales of other foreclosed assets		3,161	4,072
Total financed sales of other foreclosed and real estate assets		6,065	8,015
Transfer Of Loans Held For Sale To Portfolio Loans 1		0	3,821
Noncash Transfer To Securities From Loans Resulting From Securitization	[1]	174,620	170,248
Trades receivables from brokers and counterparties		53,192	87,590	$ 46,630
Trades Payables To Brokers And Counterparties		5,128	32,774
Recognition of mortgage servicing rights on securitizations or asset transfers		$ 2,763	$ 2,136

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