Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Consolidated Balance Sheets [Abstract]
Allowances	$ 13,315	$ 15,508
Preferred shares, par value	$ 0.001	$ 0.001
Preferred shares, authorized	5,000,000	5,000,000
Common shares, par value	$ 0.001	$ 0.001
Common shares, authorized	250,000,000	250,000,000
Common shares, issued	91,047,297	90,306,432
Common shares, outstanding	88,662,845	89,807,146
Treasury stock, shares	2,384,452	499,286