Loans Receivable and Allowance for Loan Losses - Average Recorded Investment, Interest Income, and Cash Basis Interest Related to Impaired Loans (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Without an allowance recorded:
Average Recorded Investment	$ 242,980	$ 330,190	$ 396,575
Interest Income Recognized	8,765	10,714	12,216
Cash Basis Interest Income	8,865	10,922	12,677
Residential \| Full documentation interest-only
With an allowance recorded:
Average Recorded Investment	39,506	84,264	106,720
Interest Income Recognized	860	1,860	2,938
Cash Basis Interest Income	877	1,920	3,068
Without an allowance recorded:
Average Recorded Investment	0	0	11,547
Interest Income Recognized	0	0	0
Cash Basis Interest Income	0	0	0
Residential \| Full documentation amortizing
With an allowance recorded:
Average Recorded Investment	52,426	38,340	30,790
Interest Income Recognized	1,893	1,491	948
Cash Basis Interest Income	1,920	1,498	974
Without an allowance recorded:
Average Recorded Investment	0	365	3,517
Interest Income Recognized	0	0	0
Cash Basis Interest Income	0	0	0
Residential \| Reduced documentation interest-only
With an allowance recorded:
Average Recorded Investment	66,321	112,172	145,490
Interest Income Recognized	1,910	3,646	4,179
Cash Basis Interest Income	1,923	3,671	4,371
Without an allowance recorded:
Average Recorded Investment	0	0	1,669
Interest Income Recognized	0	0	0
Cash Basis Interest Income	0	0	0
Residential \| Reduced documentation amortizing
With an allowance recorded:
Average Recorded Investment	30,310	22,137	25,460
Interest Income Recognized	1,927	655	696
Cash Basis Interest Income	1,936	653	729
Multi-family
With an allowance recorded:
Average Recorded Investment	14,390	30,291	19,130
Interest Income Recognized	415	1,320	737
Cash Basis Interest Income	417	1,339	789
Without an allowance recorded:
Average Recorded Investment	16,935	17,225	33,193
Interest Income Recognized	857	632	1,606
Cash Basis Interest Income	862	633	1,671
Commercial real estate
With an allowance recorded:
Average Recorded Investment	11,875	17,341	8,112
Interest Income Recognized	333	1,065	367
Cash Basis Interest Income	348	1,154	377
Without an allowance recorded:
Average Recorded Investment	5,632	2,853	10,947
Interest Income Recognized	522	0	745
Cash Basis Interest Income	528	0	698
Consumer and other loans \| Home equity lines of credit
With an allowance recorded:
Average Recorded Investment	5,585	5,202	0
Interest Income Recognized	48	45	0
Cash Basis Interest Income	$ 54	$ 54	$ 0

Impaired Financing Receivable, with No Related Allowance [Abstract]

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- Definition

Impaired Financing Receivable, with Related Allowance [Abstract]

+ References

No definition available.

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- Definition

Average amount of investment of impaired financing receivables with related allowance for credit losses and without a related allowance for credit losses.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 15
-Subparagraph (c)(1)
-URI http://asc.fasb.org/extlink&oid=49124121&loc=d3e5212-111524

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 17
-URI http://asc.fasb.org/extlink&oid=49124121&loc=d3e5258-111524

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- Definition

Amount of interest income recognized that the financing receivables (with related allowance for credit losses and without a related allowance for credit losses) were impaired.

+ References

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- Definition

Amount of interest income recognized on a cash-basis method of accounting that the financing receivables (with related allowance for credit losses and without a related allowance for credit losses) were impaired.

+ References

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Amount of average investment of impaired financing receivables for which there is no related allowance for credit losses.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 17
-URI http://asc.fasb.org/extlink&oid=49124121&loc=d3e5258-111524

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 15
-Subparagraph (c)(1)
-URI http://asc.fasb.org/extlink&oid=49124121&loc=d3e5212-111524

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- Definition

Amount of interest income, recognized on accrual basis, on financing receivables that are recognized as impaired, for which there is no related allowance for credit losses.

+ References

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- Definition

Amount of interest income, recognized on cash basis, on financing receivables, for which there is no related allowance for credit losses and are recognized as impaired.

+ References

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Amount of interest income, recognized on accrual basis, on financing receivables, for which there is a related allowance for credit losses and are recognized as impaired.

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