Aggregate notional amount specified by the derivative(s). Expressed as an absolute value.

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The estimated net amount of existing gains or losses on cash flow hedges at the reporting date expected to be reclassified to earnings within the next 12 months.

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- Definition

The aggregate fair value of assets that are already posted, at the end of the reporting period, as collateral for derivative instruments with credit-risk-related contingent features.

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- Definition

Nominal or face amount used to calculate payments on the derivative asset.

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Fair value, after the 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 not elected to be offset.

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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.

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Interest Rate Contracts - Narrative (Details) - USD ($)	3 Months Ended
Interest Rate Contracts - Narrative (Details) - USD ($)	Mar. 31, 2018	Dec. 31, 2017	Nov. 01, 2017	Apr. 01, 2016
Derivative [Line Items]
Income expected to be reclassified in next 12 months	$ 1,000,000
Interest Rate Swap
Derivative [Line Items]
Notional amount	200,000,000.0			$ 100,000,000.0
Derivative asset	922,000	$ 967,000
Collateral posted	0
Operating Partnership \| Interest Rate Swap
Derivative [Line Items]
Derivative asset	107,000	65,000
Recurring \| Interest Rate Swap
Derivative [Line Items]
Derivative asset	1,029,000	1,032,000
Recurring \| Significant Other Observable Inputs \| Interest Rate Swap
Derivative [Line Items]
Derivative asset	$ 1,029,000	$ 1,032,000
Recurring \| Significant Other Observable Inputs \| Operating Partnership \| Interest Rate Swap
Derivative [Line Items]
Notional amount of swaps novated			$ 100,000,000