Derivative Instruments - Gross and Net Amounts of Derivative Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Fair Value of Assets
Gross derivative amounts recognized in the balance sheet	$ 1,168	$ 468
Gross derivative amounts not offset in the balance sheet that are eligible for offsetting	(52)	(67)
Net amount	1,116	401
Fair Value of Liabilities
Gross derivative amounts recognized in the balance sheet	1,452	783
Gross derivative amounts not offset in the balance sheet that are eligible for offsetting	(52)	(67)
Net amount	$ 1,400	$ 716

Fair value, before effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes assets not subject to a master netting arrangement and elected not to be offset.

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Fair value of liability associated with financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset.

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