HMBS Related Obligations - Additional Information (Detail) (USD $)	12 Months Ended
Dec. 31, 2013	Jun. 30, 2014	Dec. 31, 2012
Other Liabilities Disclosure [Abstract]
HMBS related obligations	$ 8,652,746,000	$ 9,472,666,000	$ 5,874,552,000
Average remaining life of HMBS related obligations	4 years
Weighted-average interest rate to HMBS related obligations	4.40%		4.83%
Residential loans and real estate owned pledged as collateral	$ 8,000,000,000us-gaap_LoansPledgedAsCollateral

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.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 50

-Paragraph 5

-URI http://asc.fasb.org/extlink&oid=35738203&loc=d3e5086-111524

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 860

-SubTopic 30

-Section 45

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6467456&loc=d3e113888-111728

Name:	us-gaap_LoansPledgedAsCollateral
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant