Fair Value Fair Value - Fair Value Option Quantitative Disclosures (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Fair Value, Option, Quantitative Disclosures [Line Items]
Loans Receivable, Fair Value Disclosure	$ 12,204,837	$ 11,832,630
Fair Value Option Assets Fair Value Balance	12,204,837	11,832,630
Fair Value Option Unpaid Principal Asset Balance	14,594,885	14,428,943
Mortgage-backed debt at fair value	635,239	653,167
Beneficial Interest At Fair Value Unpaid Principal Balance	639,095	657,174
Home Equity Conversion Mortgage Backed Security Related Obligations	10,304,384	9,951,895
Home Equity Conversion Mortgage Backed Security Related Obligations Unpaid Principal Balance	9,487,008	9,172,083
Fair Value Option Liabilities Fair Value Balance	10,939,623	10,605,062
Fair Value Option Unpaid Principal Liability Balance	10,126,103	9,829,257
Reverse Loans [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Loans Receivable, Fair Value Disclosure	10,429,893	10,064,365
Loans Receivable At Fair Value Unpaid Principal Balance	9,663,598	9,340,270
Forward Loans Held for Sale [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Loans Receivable, Fair Value Disclosure	1,156,187	1,124,615
Loans Receivable At Fair Value Unpaid Principal Balance	1,102,720	1,071,787
Forward Loans in Non-Residual Trusts [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Loans Receivable, Fair Value Disclosure	567,912	586,433
Loans Receivable At Fair Value Unpaid Principal Balance	632,326	650,382
Charged Off Loans [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Loans Receivable, Fair Value Disclosure	50,845	57,217
Loans Receivable At Fair Value Unpaid Principal Balance	$ 3,196,241	$ 3,366,504