Mortgage Servicing Rights - Schedule of Activity Related to Capitalized MSRs (Detail) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2016 USD ($) loan	Jun. 30, 2015 USD ($)	Jun. 30, 2016 USD ($)	Jun. 30, 2015 USD ($)
Mortgage Servicing Rights
Beginning balance			$ 412,348
Ending balance	$ 468,093		468,093
Purchase of mortgage servicing rights			43,374
MSRs
Mortgage Servicing Rights
Beginning balance	421,651	$ 375,159	412,348	$ 375,907
Additions, following sale of loan	29,053	43,209	64,026	67,391
Purchases	44,774		44,774
Amortization	(23,233)	(19,750)	(45,956)	(38,570)
Pre-payments and write-offs	(4,152)	(3,598)	(7,099)	(9,708)
Ending balance	468,093	$ 395,020	468,093	$ 395,020
HUD Loan Portfolio Acquired
Mortgage Servicing Rights
Unpaid principal balance of loans serviced	3,800,000		3,800,000
HUD Loan Portfolio Acquired \| MSRs
Mortgage Servicing Rights
Purchases	44,800
Purchase of mortgage servicing rights	43,400
Remaining amount due on purchase of servicing portfolio	$ 1,400		1,400
Number of defaulted loans to be resolved as a condition of the purchase \| loan	1
Unpaid principal balance of loans serviced	$ 3,800,000		$ 3,800,000
Weighted average estimated remaining life of acquired servicing portfolio	10 years 9 months 18 days

Carrying value as of the balance sheet date of obligations incurred and payable, pertaining to costs that are statutory in nature, are incurred on contractual obligations, or accumulate over time and for which invoices have not yet been received or will not be rendered. Examples include taxes, interest, rent and utilities.

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The cash outflow to obtain servicing rights, which contractually entitle the servicer to receive fees and ancillary revenues for performing billing, collection, disbursement and recordkeeping services in connection with a mortgage portfolio. Rights may be obtained via (1) acquisition or assumption of a servicing obligation that does not relate to financial assets of the servicer or its consolidated affiliates; or (2) by originating mortgage loans and then (a) transferring the loans to a Variable Interest Entity (VIE) in a transaction that meets the necessary transfer and classification requirements, or (b) transferring the loans in a transaction that meets the requirements for sale accounting.

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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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Amount of other-than-temporary impairment (OTTI) applied to contract to service financial assets under which the benefits of servicing are expected to more than adequately compensate the servicer.

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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 amortization 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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The weighted average estimated remaining life of servicing portfolio acquired from a third-party servicer.

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The number of defaulted loans to be resolved as a condition of the purchase of mortgage servicing rights.

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Amount of additions from transfer to 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 additions from purchases of new servicing assets, subsequently measured at amortized cost, from a third-party servicer.

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