CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) (USD $) In Thousands, except Share data	Jun. 30, 2011	Dec. 31, 2010
CONDENSED CONSOLIDATED BALANCE SHEETS
Accounts receivable, allowance for doubtful accounts (in dollars)	$ 13,528	$ 10,249
Preferred shares, par value (in dollars per share)	$ 0.001	$ 0.001
Preferred shares, authorized	5,000,000	5,000,000
Preferred shares, outstanding	0	0
Common shares, par value (in dollars per share)	$ 0.001	$ 0.001
Common shares, authorized	250,000,000	250,000,000
Common shares, issued	89,919,925	88,600,860
Common shares, outstanding	89,390,187	88,065,859
Treasury stock, shares	529,738	535,001