Condensed Consolidated Balance Sheets Parenthetical (USD $) In Millions, except Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Allowance for Doubtful Accounts Receivable, Current	$ 2.6	$ 1.5
Common Stock, Par or Stated Value Per Share	$ 0.001	$ 0.001
Common Stock, Shares Authorized	150,000,000	150,000,000
Common Stock, Shares, Issued	59,821,243	59,704,943
Common Stock, Shares, Outstanding	50,024,780	49,525,594
Preferred Stock, Par or Stated Value Per Share	$ 0.001	$ 0.001
Preferred Stock, Shares Authorized	5,000,000	5,000,000
Preferred Stock, Shares Issued	0	0
Preferred Stock, Shares Outstanding	0	0
Treasury Stock, Shares	9,546,147	9,333,266