The fair value of available-for-sale securities that serve as collateral for borrowings.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
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Contractual interest rate for funds borrowed, under the debt agreement.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
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Reference 2: http://www.xbrl.org/2003/role/presentationRef
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Detail information of subsequent event by type. User is expected to use existing line items from elsewhere in the taxonomy as the primary line items for this disclosure, which is further associated with dimension and member elements pertaining to a subsequent event.

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No definition available.

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Subsequent Event - Additional Information (Detail) - USD ($) $ in Thousands	Feb. 17, 2017	Dec. 31, 2016	Dec. 31, 2015
Subsequent Event [Line Items]
Debt		$ 163,143	$ 172,034
Subsequent Events \| Margin borrowing facilities
Subsequent Event [Line Items]
Debt	$ 74,800
Collateral for borrowed securities	$ 95,000
Subsequent Events \| Margin borrowing facilities \| Fed Funds Effective Rate \| Maximum
Subsequent Event [Line Items]
Stated interest rate	1.00%