Available-for-Sale Securities (Narrative) (Details)	12 Months Ended
Jun. 30, 2017
Schedule of Available-for-sale Securities [Line Items]
Weighted average effective maturity	7 months

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.

No definition available.

Name:	us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration