Condensed Consolidated Balance Sheets (Parenthetical) (Unaudited) - $ / shares	Mar. 31, 2016	Dec. 31, 2015	Mar. 31, 2015
Statement of Financial Position [Abstract]
Common shares, par value (dollars per share)	$ 0	$ 0	$ 0
Common shares, shares authorized (shares)	63,000,000	63,000,000	42,000,000
Common shares, shares issued (shares)	29,430,000	29,353,000	29,430,000
Preferred shares, par value (dollars per share)	$ 0	$ 0	$ 0
Preferred shares, shares authorized (shares)	1,000,000	1,000,000	1,000,000
Preferred shares, shares issued (shares)	0	0	0
Treasury shares, at cost (shares)	1,185,000	1,397,000	859,000