Loans Receivable and Allowance for Loan Losses (Details 8) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Financing Receivable, Impaired
Loans receivable	$ 11,957,448	$ 12,442,066
Unpaid principal balance	289,737	483,132
Recorded investment	248,436	384,522
Related allowance	(19,732)	(21,531)
Net investment	228,704	362,991
Residential mortgage loans \| Full documentation interest-only loans
Financing Receivable, Impaired
Unpaid principal balance, loans with an allowance recorded	55,352	142,659
Recorded investment, loans with an allowance recorded	46,331	109,877
Related allowance	(3,391)	(6,019)
Net investment, loans with an allowance recorded	42,940	103,858
Residential mortgage loans \| Full documentation amortizing loans
Financing Receivable, Impaired
Unpaid principal balance, loans with an allowance recorded	43,044	41,136
Recorded investment, loans with an allowance recorded	39,994	36,091
Related allowance	(1,425)	(2,458)
Net investment, loans with an allowance recorded	38,569	33,633
Residential mortgage loans \| Reduced documentation interest-only loans
Financing Receivable, Impaired
Unpaid principal balance, loans with an allowance recorded	90,171	183,280
Recorded investment, loans with an allowance recorded	76,960	140,357
Related allowance	(4,661)	(7,673)
Net investment, loans with an allowance recorded	72,299	132,684
Residential mortgage loans \| Reduced documentation amortizing loans
Financing Receivable, Impaired
Unpaid principal balance, loans with an allowance recorded	19,463	30,660
Recorded investment, loans with an allowance recorded	18,117	25,605
Related allowance	(827)	(2,202)
Net investment, loans with an allowance recorded	17,290	23,403
Multi-family
Financing Receivable, Impaired
Unpaid principal balance, loans with an allowance recorded	34,972	19,748
Unpaid principal balance, loans without an allowance recorded	16,308	39,871
Recorded investment, loans with an allowance recorded	28,109	19,748
Recorded investment, loans without an allowance recorded	14,502	32,790
Related allowance	(3,172)	(2,877)
Net investment, loans with an allowance recorded	24,937	16,871
Net investment, loans without an allowance recorded	14,502	32,790
Commercial real estate
Financing Receivable, Impaired
Unpaid principal balance, loans with an allowance recorded	24,991	5,790
Unpaid principal balance, loans without an allowance recorded		19,988
Recorded investment, loans with an allowance recorded	19,270	5,790
Recorded investment, loans without an allowance recorded		14,264
Related allowance	(2,446)	(302)
Net investment, loans with an allowance recorded	16,824	5,488
Net investment, loans without an allowance recorded		14,264
Consumer and other loans \| Home equity and other consumer
Financing Receivable, Impaired
Unpaid principal balance, loans with an allowance recorded	5,436
Recorded investment, loans with an allowance recorded	5,153
Related allowance	(3,810)
Net investment, loans with an allowance recorded	1,343
Loans in process of foreclosure collateralized by residential real estate property
Financing Receivable, Impaired
Loans receivable	$ 24,700

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

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Amount of allowance for credit losses related to recorded investment.

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Amount before allowance and after 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.

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