Condensed Consolidated Statements of Financial Position (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Current Assets
Allowance for Doubtful Accounts Receivable, Current	$ 1,866	$ 1,777
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)	30,560,682	30,495,737
Common shares, treasury (in shares)	7,391,775	7,456,720