Residential Loans - Additional Information (Details) $ in Thousands	12 Months Ended
Dec. 31, 2016 USD ($) loan	Dec. 31, 2015 USD ($) loan	Dec. 31, 2014 USD ($)
Mortgage Loans on Real Estate [Line Items]
Trading	$ 445,687	$ 404,011
Transfers from loans held-for-sale to loans held-for-investment	1,063,860	1,555,814	$ 633,707
Transfers from loans held-for-investment to loans held-for-sale	$ 359,005	$ 154,012	$ 0
Fixed Rate Residential Mortgage
Mortgage Loans on Real Estate [Line Items]
Weighted average rate on loans	4.10%
Held-for sale residential loans \| FHLB Chicago
Mortgage Loans on Real Estate [Line Items]
Residential mortgage loans securing FHLB advances	$ 2,250,000
Residential Loans
Mortgage Loans on Real Estate [Line Items]
Number of loans \| loan	1,114	1,763
Principal value	$ 830,000	$ 1,090,000
Loan market valuation adjustment	830,000	1,110,000
Principal value	4,850,000	10,210,000
Principal balance of loans sold during period	4,040,000	9,040,000
Valuation adjustments	6,000	4,000
Loan pledged as collateral	534,000
Loans held as assets amount in foreclosure	$ 1,000
Residential Loans \| Financing Receivables, Equal to Greater than 90 Days Past Due
Mortgage Loans on Real Estate [Line Items]
Loan market valuation adjustment		$ 1,000
Number of loans past due \| loan	0	1
Number of loans in foreclosure \| loan		1
Residential Loans \| Financing Receivables, Receivables In Foreclosure
Mortgage Loans on Real Estate [Line Items]
Loan market valuation adjustment		$ 1,000
Residential loans, at lower of cost or fair value
Mortgage Loans on Real Estate [Line Items]
Number of loans \| loan	7	9
Principal value	$ 2,000	$ 2,000
Loan market valuation adjustment	$ 1,000	$ 1,000
Number of loans in foreclosure \| loan	0	1
Loans held as assets, 90 days or more past due	$ 300	$ 400
Loans held as assets amount in foreclosure		$ 100
Residential loans, at lower of cost or fair value \| Financing Receivables, Equal to Greater than 90 Days Past Due
Mortgage Loans on Real Estate [Line Items]
Number of loans past due \| loan	1	1
Residential Loans Held For Investment at Fair Value
Mortgage Loans on Real Estate [Line Items]
Number of loans \| loan	3,068	2,398
Principal value	$ 2,233,797	$ 1,758,990
Loan market valuation adjustment		$ 1,790,000
Number of loans past due \| loan	1	0
Number of loans in foreclosure \| loan	0	0
Valuation adjustments	$ (23,000)	$ (6,000)
Transfers from loans held-for-sale to loans held-for-investment	1,060,000	1,500,000
Transfers from loans held-for-investment to loans held-for-sale	$ 56,000	$ 143,000
FICO credit score	773
Loan to value ratio	65.00%
Percentage of loans with fixed interest rate	99.50%
Residential Loans Held For Investment at Fair Value \| Hybrid Residential Mortgages
Mortgage Loans on Real Estate [Line Items]
Weighted average rate on loans	3.83%
Residential Loans Held For Investment at Fair Value \| Originated In 2014 and 2016
Mortgage Loans on Real Estate [Line Items]
Percentage of loan portfolio	89.00%
Residential Loans Held For Investment at Fair Value \| Originated During 2013
Mortgage Loans on Real Estate [Line Items]
Percentage of loan portfolio	5.00%
Residential Loans Held For Investment at Fair Value \| Originated In 2012 And Prior Years
Mortgage Loans on Real Estate [Line Items]
Percentage of loan portfolio	6.00%
Residential Loans Held For Investment at Fair Value \| Sequoia Entities
Mortgage Loans on Real Estate [Line Items]
Number of loans \| loan	3,735	4,545
Principal value	$ 887,000	$ 1,120,000
Loan market valuation adjustment	792,000	1,020,000
Loans held as assets, 90 days or more past due	19,000	27,000
Loans held as assets amount in foreclosure	$ 11,000	32,000
FICO credit score	728
Loan to value ratio	66.00%
Valuation adjustments	$ (14,000)	$ 7,000
MSRs
Mortgage Loans on Real Estate [Line Items]
Mortgage servicing rights	$ 2,320,000

Fair Value, Option, Loans Held As Assets, Aggregate Amount In Foreclosure

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The weighted average FICO score for borrowers at the time loans were originated.

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Financing Receivable, Loan To Value Ratio

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Financing Receivable, Number Of Loans In Foreclosure

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Financing Receivable, Number Of Loans Past Due

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Financing Receivables, Weighted Average Interest Rate

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Loans Receivable, Percentage Bearing Fixed Interest, Percentage Rate

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Percentage Of Loan Portfolio

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Principal Balance of Loans Acquired During Period

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Principal Balance of Loans Sold During Period

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For each line item in the statement of financial position, the amounts of gains and losses from fair value changes included in earnings.

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This item represents the aggregate fair value of loans held as assets that are 90 days or more past due for which the fair value option has been elected.

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Amount of the collateral pledged in support of federal home loan bank advances outstanding.

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Amount after allowance and 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 and loans held for sale.

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Carrying amount as of the balance sheet date of loans that have been pledged as collateral for borrowings. If the secured party has the right by contract or custom to sell or re-pledge the collateral, then the debtor reclassifies that asset and report that asset in its statement of financial position separately from other assets not so encumbered.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Indicates the number of mortgages under each classification.

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Amount of increase (decrease) in mortgage loans on real estate.

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This is the sum of principal amount outstanding for both securitized and unsecuritized loans of all types.

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Amortized amount of contract to service financial assets under which the benefits of servicing are expected to more than adequately compensate the servicer.

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Amount of investments in debt and equity securities and other forms of securities that provide ownership interests classified as trading.

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Value of loans held-for-sale transferred to loans held in the entity's portfolio in noncash transactions.

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Value of loans and leases held in the entity's portfolio transferred to loans and leases held-for-sale in noncash transactions.

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