Derivative Instruments - Schedule of Offsetting Derivative Asset and Liability Positions (Details) - Counterparty A - USD ($) $ in Thousands	Sep. 30, 2018	Jun. 30, 2018
Derivatives, Fair Value [Line Items]
Derivative asset, fair value	$ 66	$ 0
Derivative asset, netting adjustment	(66)	0
Derivative asset, cash collateral posted	0	0
Derivative asset, net	0	0
Derivative liability, fair value	7,851	3,686
Derivative liability, netting adjustment	(66)	0
Derivative liability, cash collateral posted	2,628	0
Derivative liability, net	$ 5,157	$ 3,686

Amount of obligation to return cash collateral under master netting arrangements offset against derivative assets.

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