CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Mar. 31, 2012	Dec. 31, 2011
CONDENSED CONSOLIDATED BALANCE SHEETS
Receivables, allowance for doubtful accounts (in dollars)	$ 4,613	$ 4,225
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized	75,000,000	75,000,000
Preferred stock, shares issued	0	0
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issued	34,240,377	34,236,402
Common stock, shares outstanding	34,240,377	34,236,402