Loans Receivable (excluding Covered Loans) (Details) (USD $)	12 Months Ended
Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2010
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable, gross	$ 7,866,336,000	$ 8,299,074,000
Ratio of type of loan to total loans receivable	100.00%	100.00%
Allowance for probable losses	133,147,000	157,160,000	163,094,000
Loans in process	213,286,000	170,229,000
Discount on Acquired Loans	33,484,000	0
Loans and Leases Receivable, Deferred Income	34,421,000	35,808,000
Charges against loans receivable	414,338,000	363,197,000
Loans receivable, net	7,451,998,000	7,935,877,000
Single-family Residential [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable, gross	5,779,264,000	6,218,878,000
Ratio of type of loan to total loans receivable	73.50%	74.90%
Allowance for probable losses	81,815,000	83,307,000	47,160,000
Construction, Speculative [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable, gross	131,526,000	140,459,000
Ratio of type of loan to total loans receivable	1.60%	1.70%
Allowance for probable losses	12,060,000	13,828,000	26,346,000
Construction, Custom [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable, gross	211,690,000	279,851,000
Ratio of type of loan to total loans receivable	2.70%	3.40%
Allowance for probable losses	347,000	623,000	770,000
Land, Acquisition and Development [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable, gross	128,379,000	200,692,000
Ratio of type of loan to total loans receivable	1.70%	2.40%
Allowance for probable losses	15,598,000	32,719,000	61,637,000
Land, Consumer Lot Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable, gross	141,844,000	163,146,000
Ratio of type of loan to total loans receivable	1.80%	2.00%
Allowance for probable losses	4,937,000	5,520,000	4,793,000
Multi Family Housing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable, gross	710,741,000	700,673,000
Ratio of type of loan to total loans receivable	9.00%	8.40%
Allowance for probable losses	5,280,000	7,623,000	5,050,000
Commercial Real Estate Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable, gross	406,364,000	303,442,000
Ratio of type of loan to total loans receivable	5.20%	3.70%
Allowance for probable losses	1,956,000	4,331,000	3,165,000
Commercial and Industrial Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable, gross	166,115,000	109,332,000
Ratio of type of loan to total loans receivable	2.10%	1.30%
Allowance for probable losses	7,626,000	5,099,000	6,193,000
Home Equity Line of Credit [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable, gross	126,942,000	115,092,000
Ratio of type of loan to total loans receivable	1.60%	1.40%
Allowance for probable losses	965,000	1,139,000	586,000
Consumer Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable, gross	63,471,000	67,509,000
Ratio of type of loan to total loans receivable	0.80%	0.80%
Allowance for probable losses	2,563,000	2,971,000	7,394,000
Non-Acquired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable, gross	7,755,219,000	8,299,074,000
Ratio of type of loan to total loans receivable	98.60%	100.00%
Non-Acquired Loans [Member] \| Single-family Residential [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable, gross	5,778,922,000	6,218,878,000
Ratio of type of loan to total loans receivable	73.50%	74.90%
Non-Acquired Loans [Member] \| Construction, Speculative [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable, gross	129,637,000	140,459,000
Ratio of type of loan to total loans receivable	1.60%	1.70%
Non-Acquired Loans [Member] \| Construction, Custom [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable, gross	211,690,000	279,851,000
Ratio of type of loan to total loans receivable	2.70%	3.40%
Non-Acquired Loans [Member] \| Land, Acquisition and Development [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable, gross	124,677,000	200,692,000
Ratio of type of loan to total loans receivable	1.60%	2.40%
Non-Acquired Loans [Member] \| Land, Consumer Lot Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable, gross	141,844,000	163,146,000
Ratio of type of loan to total loans receivable	1.80%	2.00%
Non-Acquired Loans [Member] \| Multi Family Housing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable, gross	710,140,000	700,673,000
Ratio of type of loan to total loans receivable	9.00%	8.40%
Non-Acquired Loans [Member] \| Commercial Real Estate Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable, gross	319,210,000	303,442,000
Ratio of type of loan to total loans receivable	4.10%	3.70%
Non-Acquired Loans [Member] \| Commercial and Industrial Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable, gross	162,823,000	109,332,000
Ratio of type of loan to total loans receivable	2.10%	1.30%
Non-Acquired Loans [Member] \| Home Equity Line of Credit [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable, gross	112,902,000	115,092,000
Ratio of type of loan to total loans receivable	1.40%	1.40%
Non-Acquired Loans [Member] \| Consumer Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable, gross	63,374,000	67,509,000
Ratio of type of loan to total loans receivable	0.80%	0.80%
Acquired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable, gross	111,117,000	0
Ratio of type of loan to total loans receivable	1.40%	0.00%
Acquired Loans [Member] \| Single-family Residential [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable, gross	342,000	0
Ratio of type of loan to total loans receivable	0.00%	0.00%
Acquired Loans [Member] \| Construction, Speculative [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable, gross	1,889,000	0
Ratio of type of loan to total loans receivable	0.00%	0.00%
Acquired Loans [Member] \| Construction, Custom [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable, gross	0	0
Ratio of type of loan to total loans receivable	0.00%	0.00%
Acquired Loans [Member] \| Land, Acquisition and Development [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable, gross	3,702,000	0
Ratio of type of loan to total loans receivable	0.10%	0.00%
Acquired Loans [Member] \| Land, Consumer Lot Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable, gross	0	0
Ratio of type of loan to total loans receivable	0.00%	0.00%
Acquired Loans [Member] \| Multi Family Housing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable, gross	601,000	0
Ratio of type of loan to total loans receivable	0.00%	0.00%
Acquired Loans [Member] \| Commercial Real Estate Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable, gross	87,154,000	0
Ratio of type of loan to total loans receivable	1.10%	0.00%
Acquired Loans [Member] \| Commercial and Industrial Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable, gross	3,292,000	0
Ratio of type of loan to total loans receivable	0.00%	0.00%
Acquired Loans [Member] \| Home Equity Line of Credit [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable, gross	14,040,000	0
Ratio of type of loan to total loans receivable	0.20%	0.00%
Acquired Loans [Member] \| Consumer Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable, gross	$ 97,000	$ 0
Ratio of type of loan to total loans receivable	0.00%	0.00%

Amount of deferred interest and fee income, unamortized costs incurred to originate loans and leases, unamortized loan commitments and loan syndication fees, and premiums over or discounts from face amounts of acquired loans. Excludes amounts for loans and leases covered under loss sharing agreements.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher OTS

-Name Federal Regulation (FR)

-Number Title 12

-Section 563c.102

-Paragraph 8

-Subparagraph a(i-v)

-Chapter V

-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 AICPA

-Name Statement of Position (SOP)

-Number 01-6

-Paragraph 13

-Subparagraph e

-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 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher OTS

-Name Federal Regulation (FR)

-Number Title 12

-Section 563c.102

-Paragraph 8

-Subparagraph f

-Chapter V

-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 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 20

-Section 50

-Paragraph 3

-URI http://asc.fasb.org/extlink&oid=6378556&loc=d3e10152-111534

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 7

-Article 9

Reference 6: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 50

-Paragraph 4

-URI http://asc.fasb.org/extlink&oid=7512638&loc=d3e5074-111524

Reference 7: http://www.xbrl.org/2003/role/presentationRef

-Publisher OTS

-Name Federal Regulation (FR)

-Number Title 12

-Section 563c.102

-Paragraph 8

-Subparagraph e

-Chapter V

-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 8: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 13

-Paragraph 23

-Subparagraph a(i)(d)

-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 9: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 840

-SubTopic 30

-Section 50

-Paragraph 4

-Subparagraph (a)(4)

-URI http://asc.fasb.org/extlink&oid=6952072&loc=d3e45377-112738

Reference 10: 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)

-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

+ Details

- Definition

Amount after allowance and deduction of deferred interest and fees, unamortized costs and premiums and discounts from face amounts, of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Excludes loans and leases covered under loss sharing agreements.

+ References+ Details