Condensed Consolidated Statements of Earnings and Comprehensive Income (Unaudited) (Parentheticals) - USD ($)  | 
3 Months Ended | |
|---|---|---|
Sep. 30, 2016  | 
Sep. 30, 2015  | 
|
| Unrealized losses on available-for-sale investments, net of tax | $ (171) | $ 3,752 | 
| X | ||||||||||
- Definition Amount of tax expense (benefit) before reclassification adjustments of unrealized holding gain (loss) on available-for-sale securities. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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