Condensed Consolidated Balance Sheets (Unaudited) (Parenthetical) (USD $) In Millions, except Per Share data, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
Equity:
Common stock, par value (in dollars per share)	$ 0	$ 0
Common stock, shares authorized (in shares)	150	0
Common stock, shares issued (in shares)	42.4	0
Common stock, shares outstanding (in shares)	42.4	0
Preferred stock, par value (in dollars per share)	$ 0	$ 0
Preferred stock, shares authorized (in shares)	15	0
Preferred stock, shares outstanding (in shares)	0	0
Preferred stock, shares issued (in shares)	0	0