Balance Sheet Parenthetical (Parentheticals) (USD $) In Thousands, except Share data, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Allowance for Doubtful Accounts Receivable, Current	$ 22,212	$ 22,728
Preferred Stock, Par or Stated Value Per Share	$ 0.0001	$ 0.0001
Preferred Stock, Shares Authorized	5,000,000	5,000,000
Preferred Stock, Shares Issued	0	0
Preferred Stock, Shares Outstanding	0	0
Common Stock, Par or Stated Value Per Share	$ 0.0001	$ 0.0001
Common Stock, Shares Authorized	125,000,000	125,000,000
Common Stock, Shares, Issued	59,600,713	57,800,791
Common Stock, Shares, Outstanding	57,026,957	55,109,038
Treasury Stock, Shares	2,582,520	2,638,421