Consolidated Balance Sheets Parenthetical (Parentheticals) (USD $) In Millions, except Share data, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Allowance for doubtful accounts	$ 5.4	$ 5.4
Class A Common Shares [Member]
Common shares, par value	$ 0.01	$ 0.01
Common shares, shares authorized	100,000	100,000
Common shares, shares issued	100,000	100,000
Common shares, shares outstanding	100,000	100,000
Class B Common Shares [Member]
Common shares, par value	$ 0.01	$ 0.01
Common shares, shares authorized	1,900,000	1,900,000
Common shares, shares issued	915,391	914,935
Common shares, shares outstanding	914,669	914,259