Balance Sheet Parenthetical Parentheticals (USD $) In Thousands, except Share data, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
Allowance for Doubtful Accounts Receivable, Current	$ 4,117	$ 3,762
Common Stock, Par or Stated Value Per Share	$ 0.02	$ 0.02
Common Stock, Shares Authorized	200,000,000	200,000,000
Common Stock, Shares, Issued	49,037,808	49,037,806
Common Stock, Shares, Outstanding	47,366,753	47,629,472
Treasury Stock, Shares	1,671,055	1,408,334
Preferred Stock, Par or Stated Value Per Share	$ 0.02	$ 0.02
Preferred Stock, Shares Authorized	6,000,000	6,000,000
Preferred Stock, Shares Issued	0	0
Preferred Stock, Shares Outstanding	0	0