Loans Receivable and Allowance for Loan Losses (Details 7) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Recorded Investment
Total	$ 13,155,914	$ 13,197,560
Consumer and Other Loans
Recorded Investment
Total	264,094	282,444
Consumer and Other Loans | Home Equity
Recorded Investment
Total	231,920	259,036
Consumer and Other Loans | Other Loans
Recorded Investment
Total	32,174	23,408
Mortgage Loans (Gross)
Recorded Investment
Total	12,891,820	12,915,116
Mortgage Loans (Gross) | Residential Mortgage Loans
Recorded Investment
Total	9,711,226	10,561,539
Mortgage Loans (Gross) | Residential Mortgage Loans | Full Documentation Interest-only Loans
Recorded Investment
Total	2,001,396	2,695,940
Mortgage Loans (Gross) | Residential Mortgage Loans | Full Documentation Amortizing Loans
Recorded Investment
Total	6,304,872	6,308,047
Mortgage Loans (Gross) | Residential Mortgage Loans | Reduced Documentation Interest-only Loans
Recorded Investment
Total	1,005,295	1,145,340
Mortgage Loans (Gross) | Residential Mortgage Loans | Reduced Documentation Amortizing Loans
Recorded Investment
Total	399,663	412,212
Performing | Consumer and Other Loans | Home Equity
Recorded Investment
Total	225,461	253,041
Performing | Consumer and Other Loans | Other Loans
Recorded Investment
Total	32,125	23,335
Performing | Mortgage Loans (Gross) | Residential Mortgage Loans | Full Documentation Interest-only Loans
Recorded Investment
Total	1,901,875	2,588,437
Performing | Mortgage Loans (Gross) | Residential Mortgage Loans | Full Documentation Amortizing Loans
Recorded Investment
Total	6,260,546	6,264,110
Performing | Mortgage Loans (Gross) | Residential Mortgage Loans | Reduced Documentation Interest-only Loans
Recorded Investment
Total	891,813	1,014,039
Performing | Mortgage Loans (Gross) | Residential Mortgage Loans | Reduced Documentation Amortizing Loans
Recorded Investment
Total	365,941	377,086
Non-performing | Consumer and Other Loans | Home Equity
Recorded Investment
Total	6,459	5,995
Non-performing | Consumer and Other Loans | Other Loans
Recorded Investment
Total	49	73
Non-performing | Mortgage Loans (Gross) | Residential Mortgage Loans | Full Documentation Interest-only Loans
Recorded Investment
Total	99,521	107,503
Non-performing | Mortgage Loans (Gross) | Residential Mortgage Loans | Full Documentation Amortizing Loans
Recorded Investment
Total	44,326	43,937
Non-performing | Mortgage Loans (Gross) | Residential Mortgage Loans | Reduced Documentation Interest-only Loans
Recorded Investment
Total	113,482	131,301
Non-performing | Mortgage Loans (Gross) | Residential Mortgage Loans | Reduced Documentation Amortizing Loans
Recorded Investment
Total	$ 33,722	$ 35,126