Accumulated Other Comprehensive Loss - Schedule of Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Apr. 30, 2019	Apr. 30, 2018	Apr. 30, 2019	Apr. 30, 2018
Balance at beginning of period	$ 0	$ 0		$ 0
OCI before reclassifications	(39,493)	0	(39,493)	0
Income taxes associated with OCI before reclassifications	1,283	0	1,283	0
Amounts reclassified from AOCI	337	0	337	0
Income taxes associated with amounts reclassified from AOCI	(91)	0	(91)	0
Net OCI	(37,964)		(37,964)
Less: OCI attributable to noncontrolling interest	(73)		(73)
OCI attributable to Thor Industries Inc.	(37,891)	0	(37,891)	0
Foreign Currency Translation
Balance at beginning of period	0	0	0	0
OCI before reclassifications	(34,183)	0	(34,183)	0
Income taxes associated with OCI before reclassifications	0	0	0	0
Amounts reclassified from AOCI	0	0	0	0
Income taxes associated with amounts reclassified from AOCI	0	0	0	0
Net OCI	(34,183)	0	(34,183)	0
Less: OCI attributable to noncontrolling interest	(73)		(73)
OCI attributable to Thor Industries Inc.	(34,110)	0	(34,110)	0
Unrealized Gain (Loss) on Derivative
Balance at beginning of period	0	0	0	0
OCI before reclassifications	(5,310)	0	(5,310)	0
Income taxes associated with OCI before reclassifications	1,283	0	1,283	0
Amounts reclassified from AOCI	337	0	337	0
Income taxes associated with amounts reclassified from AOCI	(91)	0	(91)	0
Net OCI	(3,781)	0	(3,781)	0
Less: OCI attributable to noncontrolling interest			0
OCI attributable to Thor Industries Inc.	$ (3,781)	$ 0	$ (3,781)	$ 0

Accumulated change in equity from transactions and other events and circumstances from non-owner sources, net of tax effect, at period end. Excludes Net Income (Loss), and accumulated changes in equity from transactions resulting from investments by owners and distributions to owners. Includes foreign currency translation items, certain pension adjustments, unrealized gains and losses on certain investments in debt and equity securities, other than temporary impairment (OTTI) losses related to factors other than credit losses on available-for-sale and held-to-maturity debt securities that an entity does not intend to sell and it is not more likely than not that the entity will be required to sell before recovery of the amortized cost basis, as well as changes in the fair value of derivatives related to the effective portion of a designated cash flow hedge.

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