Condensed Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Statement of Financial Position [Abstract]
Allowance for doubtful accounts	$ 4,992	$ 4,883
Common shares, par value (dollars per share)	$ 0	$ 0
Common shares, shares authorized (shares)	42,000,000	42,000,000
Common shares, shares issued (shares)	28,797,000	28,797,000
Preferred shares, par value (dollars per share)	$ 0	$ 0
Preferred shares, shares authorized (shares)	1,000,000	1,000,000
Preferred shares, shares issued (shares)	0	0
Treasury shares, at cost (shares)	607,000	831,000