Consolidated Statement Of Shareholders' Equity (Deficit) (USD $) In Millions, unless otherwise specified	Total	Class A Common Shares [Member]	Class B Common Shares [Member]	Paid-In Capital [Member]	Accumulated Deficit [Member]	Accumulated Other Comprehensive Loss [Member]
Balance at Dec. 31, 2011	$ (7.3)	$ 0	$ 0	$ 2,186.1	$ (2,191.3)	$ (2.1)
Shareholders' Equity (Deficit) [Roll Forward]
Equity-based compensation expense	11.5	0	0	11.5	0	0
Repurchase of Class B common shares	(0.3)	0	0	0	(0.3)	0
Accrued charitable contribution related to the MPK Coworker Incentive Plan II, net of tax	(0.6)	0	0	(0.6)	0	0
MPK Coworker Incentive Plan II units withheld for taxes	(0.2)	0	0	(0.2)	0	0
Net income (loss)	47.7	0	0	0	47.7	0
Foreign currency translation adjustment	0.3	0	0	0	0	0.3
Balance at Jun. 30, 2012	$ 51.1	$ 0	$ 0	$ 2,196.8	$ (2,143.9)	$ (1.8)