Composition of Loan Portfolio (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013		Dec. 31, 2012	Dec. 31, 2011
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Covered Loans	$ 29,821,715		$ 27,273,707
Net deferred loan origination costs	16,274		10,757
Non-Covered Loans, Percentage	100.00%		100.00%
Allowance for losses on non-covered loans	(141,946)		(140,948)	(137,290)
Non-covered loans held for investment, net	29,696,043		27,143,516
Covered loans	2,788,618		3,284,061
Allowance for losses on covered loans	(64,069)		(51,311)	(33,323)
Total covered loans, net	2,724,549		3,232,750
Loans held for sale	306,915		1,204,370
Total loans, net	32,727,507		31,580,636
Multi-Family
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Covered Loans	20,699,927		18,595,833
Non-Covered Loans, Percentage	69.41%		68.18%
Commercial Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Covered Loans	7,364,231		7,436,598
Non-Covered Loans, Percentage	24.70%		27.27%
One-to-four family
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Covered Loans	560,730		203,435
Non-Covered Loans, Percentage	1.88%		0.75%
Covered loans	2,529,200
Acquisition, Development and Construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Covered Loans	344,100		397,917
Non-Covered Loans, Percentage	1.15%		1.46%
Mortgage Receivable
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Covered Loans	28,968,988		26,633,783
Non-Covered Loans, Percentage	97.14%		97.66%
Allowance for losses on non-covered loans	(127,840)		(127,934)	(121,995)
Commercial and Industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Covered Loans	813,691	[1],[2]	590,044
Non-Covered Loans, Percentage	2.39%		2.16%
Commercial and Industrial | Other loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Covered Loans	712,260		590,044
Lease financing, unearned income
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Covered Loans	101,431
Non-Covered Loans, Percentage	0.34%
Total Commercial and Industrial Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Covered Loans	813,691		590,044
Non-Covered Loans, Percentage	2.73%		2.16%
Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Covered Loans	39,036		49,880
Non-Covered Loans, Percentage	0.13%		0.18%
Total Other Loan Segment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Covered Loans	$ 852,727		$ 639,924
Non-Covered Loans, Percentage	2.86%		2.34%

[1] Includes lease financing receivables, all of which were current loans.

[2] Includes lease financing receivables, all of which were classified as "pass."