Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	Mar. 31, 2018	Jun. 30, 2017
Statement Of Financial Position [Abstract]
Preferred stock, par value (in dollars per share)
Preferred stock, shares authorized (in shares)	2,500,000	2,500,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Common stock, par value (in dollars per share)
Common stock, shares authorized (in shares)	15,000,000	15,000,000
Common stock, shares issued (in shares)	4,505,473	4,508,509
Common stock, shares outstanding (in shares)	4,107,538	4,111,281
Treasury stock, shares at cost (in shares)	397,935	397,228