Changes in Allowance for Loan Losses by Loan Receivable Segment (Detail) (USD $) In Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2011	Jun. 30, 2011
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses, Beginning Balance	$ 189,486	$ 201,499
Provision charged to operations	10,000	17,000
Charge-offs	(20,908)	(42,318)
Recoveries	4,139	6,536
Allowance for loan losses, Ending Balance	182,717	182,717
Mortgage loans (gross) \| One to Four Family
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses, Beginning Balance	117,722	125,524
Provision charged to operations	8,739	16,283
Charge-offs	(15,768)	(33,479)
Recoveries	4,020	6,385
Allowance for loan losses, Ending Balance	114,713	114,713
Mortgage loans (gross) \| Multi Family
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses, Beginning Balance	49,396	52,786
Provision charged to operations	825	373
Charge-offs	(3,752)	(6,696)
Recoveries		6
Allowance for loan losses, Ending Balance	46,469	46,469
Mortgage loans (gross) \| Commercial Real Estate
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses, Beginning Balance	14,782	15,563
Provision charged to operations	544	(237)
Charge-offs	(756)	(756)
Allowance for loan losses, Ending Balance	14,570	14,570
Mortgage loans (gross) \| Construction
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses, Beginning Balance	3,502	3,480
Provision charged to operations	(245)	(223)
Charge-offs	(420)	(420)
Recoveries	64	64
Allowance for loan losses, Ending Balance	2,901	2,901
Consumer and Other Loans
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses, Beginning Balance	4,084	4,146
Provision charged to operations	137	804
Charge-offs	(212)	(967)
Recoveries	55	81
Allowance for loan losses, Ending Balance	$ 4,064	$ 4,064

Reflects the gross amount charged against earnings during the period as credit losses (bad debt expense) based on review of the loan and lease portfolio and application of the methodology for estimating credit losses.

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Reflects the amount of loans and leases that have been removed, or charged off, from both loan receivables and the reserve for credit losses, typically because they are considered to be not salvageable or have been purchased by unconsolidated collection entities.

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- Definition

The allowance for loan and lease losses represents the reserve to cover probable credit losses related to specifically identified loans and leases, as well as probable credit losses inherent in the remainder of the loan portfolio as of the balance sheet date. For banks, include currently required allocated transfer risk reserves. Include carryover of or adjustments to the allowance for loan losses in connection with business combinations determined to be appropriate.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher OTS
-Name Federal Regulation (FR)
-Number Title 12
-Chapter V
-Section 563c.102
-Paragraph 8
-Subparagraph a(ii)
-Subsection I
-LegacyDoc This is a non-GAAP reference that was included in the 2009 taxonomy. It will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Staff Accounting Bulletin (SAB)
-Number Topic 6
-Section L
-Subsection 1

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 114
-Paragraph 20
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.7(d))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

Reference 5: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Article 9
-Section 03
-Paragraph 7
-Subparagraph d

Reference 6: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 5
-Paragraph 8, 9
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 7: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 30
-Section 50
-Paragraph 2
-Subparagraph (b)(1)(ii)
-URI http://asc.fasb.org/extlink&oid=6379141&loc=d3e15032-111544

+ Details