Loans Receivable and Allowance for Loan Losses (Residential Mortgage, Consumer and Other Loans, by Class and Credit Quality Indicator) (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Recorded Investment
Total	$ 11,866,764	$ 12,386,378
Past due 90 days or more	44,833	250,534
Consumer and Other Loans
Recorded Investment
Total	244,996	239,681
Past due 90 days or more	6,323	5,948
Consumer and Other Loans | Home equity lines of credit
Recorded Investment
Total	181,851	199,809
Past due 90 days or more	6,289	5,916
Consumer and Other Loans | Other loans
Recorded Investment
Total	63,145	39,872
Past due 90 days or more	34	32
Mortgage loans (gross)
Recorded Investment
Total	11,621,768	12,146,697
Past due 90 days or more	38,510	244,586
Mortgage loans (gross) | Residential Mortgage Loans
Recorded Investment
Total	7,082,224	8,037,276
Past due 90 days or more	31,869	234,378
Mortgage loans (gross) | Residential Mortgage Loans | Full documentation interest-only
Recorded Investment
Total	993,231	1,382,201
Past due 90 days or more	9,268	78,271
Mortgage loans (gross) | Residential Mortgage Loans | Full documentation amortizing loans
Recorded Investment
Total	5,048,243	5,419,457
Past due 90 days or more	9,549	42,085
Mortgage loans (gross) | Residential Mortgage Loans | Reduced documentation interest-only loans
Recorded Investment
Total	648,866	839,661
Past due 90 days or more	11,920	87,910
Mortgage loans (gross) | Residential Mortgage Loans | Reduced documentation amortizing loans
Recorded Investment
Total	391,884	395,957
Past due 90 days or more	1,132	26,112
Performing | Consumer and Other Loans | Home equity lines of credit
Recorded Investment
Total	175,562	193,861
Performing | Consumer and Other Loans | Other loans
Recorded Investment
Total	63,111	39,840
Performing | Mortgage loans (gross) | Residential Mortgage Loans | Full documentation interest-only
Recorded Investment
Total	962,798	1,281,973
Performing | Mortgage loans (gross) | Residential Mortgage Loans | Full documentation amortizing loans
Recorded Investment
Total	5,032,640	5,364,548
Performing | Mortgage loans (gross) | Residential Mortgage Loans | Reduced documentation interest-only loans
Recorded Investment
Total	608,996	721,503
Performing | Mortgage loans (gross) | Residential Mortgage Loans | Reduced documentation amortizing loans
Recorded Investment
Total	384,993	363,626
Non-performing: | Consumer and Other Loans | Home equity lines of credit
Recorded Investment
Current or past due less than 90 days		32
Past due 90 days or more	6,289	5,916
Non-performing: | Consumer and Other Loans | Other loans
Recorded Investment
Past due 90 days or more	34	32
Non-performing: | Mortgage loans (gross) | Residential Mortgage Loans | Full documentation interest-only
Recorded Investment
Current or past due less than 90 days	21,165	21,957
Past due 90 days or more	9,268	78,271
Non-performing: | Mortgage loans (gross) | Residential Mortgage Loans | Full documentation amortizing loans
Recorded Investment
Current or past due less than 90 days	6,054	12,824
Past due 90 days or more	9,549	42,085
Non-performing: | Mortgage loans (gross) | Residential Mortgage Loans | Reduced documentation interest-only loans
Recorded Investment
Current or past due less than 90 days	27,950	30,248
Past due 90 days or more	11,920	87,910
Non-performing: | Mortgage loans (gross) | Residential Mortgage Loans | Reduced documentation amortizing loans
Recorded Investment
Current or past due less than 90 days	5,759	6,219
Past due 90 days or more	$ 1,132	$ 26,112