Advances Receivable, net - Additional Information (Details) - USD ($)	12 Months Ended
Jun. 30, 2020	Jun. 30, 2019
Participation interest	100.00%	97.00%
Collection in advance	$ 11,250,000
Aircraft Purchasers Deposits
Cash advances	$ 17,474,000	$ 4,750,000

The cash inflow associated with principal collections from a borrowing supported by a written promise to pay an obligation.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 12
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=121586364&loc=d3e3179-108585

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration