CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) (USD $) In Millions, except Share data, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Statement of Financial Position [Abstract]
Property and equipment, Accumulated depreciation	$ 60.7	$ 62.2
Common stock, shares authorized	180,000,000	180,000,000
Common stock, issued	92,320,598	92,313,182
Common stock, outstanding	92,300,329	92,292,913
Treasury stock, shares	20,269	20,269