Consolidated Balance Sheets (Parenthetical) - $ / shares	Mar. 31, 2018	Mar. 31, 2017
Statement of Financial Position [Abstract]
Common stock, no par value	$ 0	$ 0
Common stock, stated value	$ 0.3	$ 0.30
Common stock, shares authorized	80,000,000	80,000,000
Common stock, shares issued	31,606,831	31,606,831
Common stock, shares outstanding	23,324,679	23,210,682
Treasury shares	8,282,152	8,396,149