Amount of assets pledged to secure a debt instrument.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 470
-Section 50
-Paragraph 3
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=6479336&loc=d3e64711-112823

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- Definition

The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(22))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(16))
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(16))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

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- Definition

Amount of current borrowing capacity under the credit facility considering any current restrictions on the amount that could be borrowed (for example, borrowings may be limited by the amount of current assets), but without considering any amounts currently outstanding under the facility.

+ References

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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.

+ References

No definition available.

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Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

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- Definition

Amount of borrowing capacity currently available under the credit facility (current borrowing capacity less the amount of borrowings outstanding).

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Secured Debt Agreements, Net - Revolving Repurchase Facilities (Detail) - Revolving Repurchase Facilities [Member]	Dec. 31, 2016 USD ($)	Dec. 31, 2016 GBP (£)	Dec. 31, 2016 EUR (€)	Dec. 31, 2015 USD ($)
Line of Credit Facility [Line Items]
Maximum Facility Size	$ 5,479,180,000			$ 4,332,267,000
Collateral Assets	5,297,728,000			3,811,792,000
Potential	4,114,580,000			2,982,833,000
Repurchase Borrowings Outstanding	3,572,837,000			2,495,805,000
Available	541,743,000			487,028,000
Morgan Stanley [Member]
Line of Credit Facility [Line Items]
Maximum Facility Size	308,500,000	£ 250,000,000		370,400,000
Collateral Assets	344,056,000			273,280,000
Potential	272,221,000			212,050,000
Repurchase Borrowings Outstanding	231,930,000			209,038,000
Available	40,291,000			3,012,000
Societe Generale [Member]
Line of Credit Facility [Line Items]
Maximum Facility Size	420,680,000		€ 400,000,000	437,320,000
Collateral Assets	274,351,000			67,416,000
Potential	207,178,000			53,933,000
Repurchase Borrowings Outstanding	207,178,000			53,933,000
JP Morgan [Member]
Line of Credit Facility [Line Items]
Maximum Facility Size	500,000,000			524,547,000
Collateral Assets	550,560,000			589,752,000
Potential	420,414,000			464,723,000
Repurchase Borrowings Outstanding	316,219,000			382,042,000
Available	104,195,000			82,681,000
Wells Fargo [Member]
Line of Credit Facility [Line Items]
Maximum Facility Size	2,000,000,000			1,000,000,000
Collateral Assets	1,718,874,000			879,155,000
Potential	1,339,942,000			687,200,000
Repurchase Borrowings Outstanding	1,107,733,000			562,382,000
Available	232,209,000			124,818,000
MetLife [Member]
Line of Credit Facility [Line Items]
Maximum Facility Size	1,000,000,000			750,000,000
Collateral Assets	1,106,017,000			593,273,000
Potential	862,454,000			462,849,000
Repurchase Borrowings Outstanding	862,454,000			324,587,000
Available				138,262,000
Bank of America [Member]
Line of Credit Facility [Line Items]
Maximum Facility Size	750,000,000			750,000,000
Collateral Assets	794,881,000			840,884,000
Potential	617,694,000			665,861,000
Repurchase Borrowings Outstanding	617,694,000			618,944,000
Available				46,917,000
Citibank [Member]
Line of Credit Facility [Line Items]
Maximum Facility Size	500,000,000			500,000,000
Collateral Assets	508,989,000			568,032,000
Potential	394,677,000			436,217,000
Repurchase Borrowings Outstanding	229,629,000			344,879,000
Available	$ 165,048,000			$ 91,338,000