Loans Receivable and Allowance for Loan Losses (Details 5) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Financing Receivable, Impaired
Unpaid Principal Balance	$ 457,440	$ 395,426
Recorded Investment	346,906	301,535
Related Allowance	(5,046)	(15,148)
Net Investment	341,860	286,387
Residential | Full Documentation Interest-only Loans
Financing Receivable, Impaired
Unpaid Principal Balance, Loans with an allowance recorded	10,740	10,588
Unpaid Principal Balance, Loans without an allowance recorded	122,275	107,332
Recorded Investment, Loans with an allowance recorded	10,740	10,588
Recorded Investment, Loans without an allowance recorded	86,607	75,791
Related Allowance	(241)	(1,240)
Net Investment, Loans with an allowance recorded	10,499	9,348
Net Investment, Loans without an allowance recorded	86,607	75,791
Residential | Full Documentation Amortizing Loans
Financing Receivable, Impaired
Unpaid Principal Balance, Loans with an allowance recorded	6,122	3,885
Unpaid Principal Balance, Loans without an allowance recorded	23,489	22,184
Recorded Investment, Loans with an allowance recorded	6,122	3,885
Recorded Investment, Loans without an allowance recorded	17,962	17,074
Related Allowance	(347)	(439)
Net Investment, Loans with an allowance recorded	5,775	3,446
Net Investment, Loans without an allowance recorded	17,962	17,074
Residential | Reduced Documentation Interest-only Loans
Financing Receivable, Impaired
Unpaid Principal Balance, Loans with an allowance recorded	12,893	11,713
Unpaid Principal Balance, Loans without an allowance recorded	166,477	156,083
Recorded Investment, Loans with an allowance recorded	12,893	11,713
Recorded Investment, Loans without an allowance recorded	116,514	109,582
Related Allowance	(277)	(1,409)
Net Investment, Loans with an allowance recorded	12,616	10,304
Net Investment, Loans without an allowance recorded	116,514	109,582
Residential | Reduced Documentation Amortizing Loans
Financing Receivable, Impaired
Unpaid Principal Balance, Loans with an allowance recorded	3,889	1,779
Unpaid Principal Balance, Loans without an allowance recorded	23,419	20,021
Recorded Investment, Loans with an allowance recorded	3,889	1,779
Recorded Investment, Loans without an allowance recorded	17,419	15,259
Related Allowance	(136)	(217)
Net Investment, Loans with an allowance recorded	3,753	1,562
Net Investment, Loans without an allowance recorded	17,419	15,259
Multi-Family
Financing Receivable, Impaired
Unpaid Principal Balance, Loans with an allowance recorded	19,704	39,399
Unpaid Principal Balance, Loans without an allowance recorded	44,341	2,496
Recorded Investment, Loans with an allowance recorded	19,704	36,273
Recorded Investment, Loans without an allowance recorded	36,412	2,496
Related Allowance	(2,576)	(8,650)
Net Investment, Loans with an allowance recorded	17,128	27,623
Net Investment, Loans without an allowance recorded	36,412	2,496
Commercial Real Estate
Financing Receivable, Impaired
Unpaid Principal Balance, Loans with an allowance recorded	10,835	19,946
Unpaid Principal Balance, Loans without an allowance recorded	13,256
Recorded Investment, Loans with an allowance recorded	10,835	17,095
Recorded Investment, Loans without an allowance recorded	7,809
Related Allowance	(1,469)	(3,193)
Net Investment, Loans with an allowance recorded	9,366	13,902
Net Investment, Loans without an allowance recorded	$ 7,809