Consolidated Balance Sheets (Parenthetical) - $ / shares	Jun. 30, 2015	Dec. 31, 2014	Jun. 30, 2014
Statement of Financial Position [Abstract]
Common stock, par value per share	$ 0.1	$ 0.1	$ 0.1
Common stock, shares authorized	80,000,000	80,000,000	80,000,000
Common stock, shares issued		3,024,000	3,024,000
Treasury shares, at cost	3,678,936	1,428,495	1,382,602