Loans Receivable (excluding Covered Loans) (Loans Receivable, Analysis of Age of Loans in Past Due Status) (Details) (USD $)
In Thousands, unless otherwise specified

Loans Receivable (excluding Covered Loans) (Loans Receivable, Analysis of Age of Loans in Past Due Status) (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2012	Sep. 30, 2011	Mar. 31, 2011
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount of Loan, Net of Charge-Offs and LIP	7,897,759	$ 8,128,845
Current	7,646,511	7,849,623
30 Days	54,011	59,026
60 Days	44,908	25,577
90 Days	152,329	194,619
Total	251,248	279,222
Ratio of past due loans to total loans, net of charge-offs and LIPs	3.18%	3.43%
Residential Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount of Loan, Net of Charge-Offs and LIP		6,217,670
Current		6,015,464
30 Days		54,140
60 Days		21,985
90 Days		126,082
Total		202,207
Ratio of past due loans to total loans, net of charge-offs and LIPs	3.10%	3.25%	3.33%
Construction, Speculative [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount of Loan, Net of Charge-Offs and LIP		115,409
Current		106,843
30 Days		330
60 Days		0
90 Days		8,236
Total		8,566
Ratio of past due loans to total loans, net of charge-offs and LIPs		7.42%
Construction, Custom [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount of Loan, Net of Charge-Offs and LIP		147,764
Current		147,129
30 Days		0
60 Days		0
90 Days		635
Total		635
Ratio of past due loans to total loans, net of charge-offs and LIPs		0.43%
Land, Acquisition and Development [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount of Loan, Net of Charge-Offs and LIP		193,613
Current		159,357
30 Days		679
60 Days		0
90 Days		33,577
Total		34,256
Ratio of past due loans to total loans, net of charge-offs and LIPs		17.69%
Land, Consumer Lot Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount of Loan, Net of Charge-Offs and LIP		163,146
Current		151,849
30 Days		1,163
60 Days		1,291
90 Days		8,843
Total		11,297
Ratio of past due loans to total loans, net of charge-offs and LIPs		6.92%
Multi Family Housing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount of Loan, Net of Charge-Offs and LIP		699,340
Current		690,765
30 Days		0
60 Days		1,202
90 Days		7,373
Total		8,575
Ratio of past due loans to total loans, net of charge-offs and LIPs		1.23%
Commercial Real Estate Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount of Loan, Net of Charge-Offs and LIP		300,307
Current		292,015
30 Days		1,016
60 Days		0
90 Days		7,276
Total		8,292
Ratio of past due loans to total loans, net of charge-offs and LIPs		2.76%
Commercial and Industrial Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount of Loan, Net of Charge-Offs and LIP		108,995
Current		106,708
30 Days		55
60 Days		553
90 Days		1,679
Total		2,287
Ratio of past due loans to total loans, net of charge-offs and LIPs		2.10%
Home Equity Line of Credit [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount of Loan, Net of Charge-Offs and LIP		115,092
Current		114,059
30 Days		452
60 Days		100
90 Days		481
Total		1,033
Ratio of past due loans to total loans, net of charge-offs and LIPs		0.90%
Consumer Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount of Loan, Net of Charge-Offs and LIP		67,509
Current		65,434
30 Days		1,191
60 Days		446
90 Days		437
Total		2,074
Ratio of past due loans to total loans, net of charge-offs and LIPs		3.07%
Non-Acquired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount of Loan, Net of Charge-Offs and LIP	7,763,449
Current	7,530,227
30 Days	48,725
60 Days	40,394
90 Days	144,103
Total	233,222
Ratio of past due loans to total loans, net of charge-offs and LIPs	3.00%
Non-Acquired Loans [Member] \| Residential Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount of Loan, Net of Charge-Offs and LIP	5,969,973
Current	5,784,832
30 Days	45,826
60 Days	28,841
90 Days	110,474
Total	185,141
Ratio of past due loans to total loans, net of charge-offs and LIPs	3.10%
Non-Acquired Loans [Member] \| Construction, Speculative [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount of Loan, Net of Charge-Offs and LIP	102,654
Current	97,455
30 Days	0
60 Days	1,635
90 Days	3,564
Total	5,199
Ratio of past due loans to total loans, net of charge-offs and LIPs	5.06%
Non-Acquired Loans [Member] \| Construction, Custom [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount of Loan, Net of Charge-Offs and LIP	145,406
Current	144,845
30 Days	0
60 Days	22
90 Days	539
Total	561
Ratio of past due loans to total loans, net of charge-offs and LIPs	0.39%
Non-Acquired Loans [Member] \| Land, Acquisition and Development [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount of Loan, Net of Charge-Offs and LIP	146,228
Current	125,100
30 Days	0
60 Days	5,452
90 Days	15,676
Total	21,128
Ratio of past due loans to total loans, net of charge-offs and LIPs	14.45%
Non-Acquired Loans [Member] \| Land, Consumer Lot Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount of Loan, Net of Charge-Offs and LIP	149,966
Current	142,155
30 Days	966
60 Days	1,204
90 Days	5,641
Total	7,811
Ratio of past due loans to total loans, net of charge-offs and LIPs	5.21%
Non-Acquired Loans [Member] \| Multi Family Housing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount of Loan, Net of Charge-Offs and LIP	677,730
Current	672,517
30 Days	0
60 Days	683
90 Days	4,530
Total	5,213
Ratio of past due loans to total loans, net of charge-offs and LIPs	0.77%
Non-Acquired Loans [Member] \| Commercial Real Estate Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount of Loan, Net of Charge-Offs and LIP	292,143
Current	286,778
30 Days	672
60 Days	1,950
90 Days	2,743
Total	5,365
Ratio of past due loans to total loans, net of charge-offs and LIPs	1.84%
Non-Acquired Loans [Member] \| Commercial and Industrial Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount of Loan, Net of Charge-Offs and LIP	94,901
Current	94,895
30 Days	5
60 Days	0
90 Days	1
Total	6
Ratio of past due loans to total loans, net of charge-offs and LIPs	0.01%
Non-Acquired Loans [Member] \| Home Equity Line of Credit [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount of Loan, Net of Charge-Offs and LIP	113,368
Current	112,657
30 Days	60
60 Days	60
90 Days	591
Total	711
Ratio of past due loans to total loans, net of charge-offs and LIPs	0.63%
Non-Acquired Loans [Member] \| Consumer Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount of Loan, Net of Charge-Offs and LIP	71,080
Current	68,993
30 Days	1,196
60 Days	547
90 Days	344
Total	2,087
Ratio of past due loans to total loans, net of charge-offs and LIPs	2.94%
Acquired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount of Loan, Net of Charge-Offs and LIP	134,310
Current	116,284
30 Days	5,286
60 Days	4,514
90 Days	8,226
Total	18,026
Ratio of past due loans to total loans, net of charge-offs and LIPs	13.42%
Acquired Loans [Member] \| Residential Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount of Loan, Net of Charge-Offs and LIP	2,093
Current	1,755
30 Days	338
60 Days	0
90 Days	0
Total	338
Ratio of past due loans to total loans, net of charge-offs and LIPs	16.15%
Acquired Loans [Member] \| Construction, Speculative [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount of Loan, Net of Charge-Offs and LIP	139
Current	139
30 Days	0
60 Days	0
90 Days	0
Total	0
Ratio of past due loans to total loans, net of charge-offs and LIPs	0.00%
Acquired Loans [Member] \| Construction, Custom [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount of Loan, Net of Charge-Offs and LIP	0
Current	0
30 Days	0
60 Days	0
90 Days	0
Total	0
Ratio of past due loans to total loans, net of charge-offs and LIPs	0.00%
Acquired Loans [Member] \| Land, Acquisition and Development [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount of Loan, Net of Charge-Offs and LIP	4,490
Current	3,937
30 Days	0
60 Days	0
90 Days	553
Total	553
Ratio of past due loans to total loans, net of charge-offs and LIPs	12.32%
Acquired Loans [Member] \| Land, Consumer Lot Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount of Loan, Net of Charge-Offs and LIP	0
Current	0
30 Days	0
60 Days	0
90 Days	0
Total	0
Ratio of past due loans to total loans, net of charge-offs and LIPs	0.00%
Acquired Loans [Member] \| Multi Family Housing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount of Loan, Net of Charge-Offs and LIP	1,229
Current	1,090
30 Days	139
60 Days	0
90 Days	0
Total	139
Ratio of past due loans to total loans, net of charge-offs and LIPs	11.31%
Acquired Loans [Member] \| Commercial Real Estate Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount of Loan, Net of Charge-Offs and LIP	101,254
Current	87,036
30 Days	4,285
60 Days	3,375
90 Days	6,558
Total	14,218
Ratio of past due loans to total loans, net of charge-offs and LIPs	14.04%
Acquired Loans [Member] \| Commercial and Industrial Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount of Loan, Net of Charge-Offs and LIP	7,765
Current	6,907
30 Days	488
60 Days	55
90 Days	315
Total	858
Ratio of past due loans to total loans, net of charge-offs and LIPs	11.05%
Acquired Loans [Member] \| Home Equity Line of Credit [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount of Loan, Net of Charge-Offs and LIP	17,215
Current	15,331
30 Days	0
60 Days	1,084
90 Days	800
Total	1,884
Ratio of past due loans to total loans, net of charge-offs and LIPs	10.94%
Acquired Loans [Member] \| Consumer Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount of Loan, Net of Charge-Offs and LIP	125
Current	89
30 Days	36
60 Days	0
90 Days	0
Total	36
Ratio of past due loans to total loans, net of charge-offs and LIPs	28.80%