INTEREST RATE SWAP DERIVATIVES - Statement of FInancial Position (Q2) (Details)	Jun. 30, 2019 USD ($) Instrument	Dec. 31, 2018 USD ($) Instrument	Dec. 31, 2017 USD ($) Instrument
Derivatives, Fair Value [Line Items]
Fair Value	$ 1,023,730	$ 300,929	$ 0
Fair Value	$ 0	$ 151,215	$ 7,899
Interest Rate Swap
Derivatives, Fair Value [Line Items]
Number of Instruments \| Instrument	4	4	2
Assets \| Interest Rate Swap
Derivatives, Fair Value [Line Items]
Number of Instruments \| Instrument	0	2	2
Fair Value	$ 0	$ 151,215	$ 7,899
Liability \| Interest Rate Swap
Derivatives, Fair Value [Line Items]
Number of Instruments \| Instrument	4	2	0
Fair Value	$ (1,023,730)	$ (300,929)	$ 0

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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Fair value, after the effects of master netting arrangements, of a financial liability or 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 liabilities not subject to a master netting arrangement and not elected to be offset.

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The number of derivative instruments of a particular group held by the entity.

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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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