Condensed Consolidated Statements of Financial Position (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Current Assets
Allowances for accounts receivable	$ 3,782	$ 3,255
Shareholders’ Equity
Preferred Shares, shares authorized (in shares)	1,000,000	1,000,000
Preferred Shares, shares issued (in shares)	0	0
Preferred Shares, shares outstanding (in shares)	0	0
Common Shares, shares authorized (in shares)	60,000,000	60,000,000
Common Shares, shares outstanding (in shares)	33,551,449	33,480,189
Common shares, treasury (in shares)	4,148,683	4,356,160