Supplemental Guarantor Information Additional Details (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2014	May 09, 2014	Mar. 31, 2014	Feb. 21, 2014	Jan. 22, 2014	Dec. 31, 2013	Oct. 18, 2013	Aug. 01, 2013	Mar. 08, 2013	Mar. 10, 2010	Aug. 05, 2014	Jul. 02, 2013	Dec. 01, 2014	Mar. 20, 2014
Debt Instrument [Line Items]
Long-term Debt, Gross	$ 3,192.4
Subordinated Debt [Member]
Debt Instrument [Line Items]
Debt Instrument, Repurchased Face Amount		42.5	50.0	20.0	30.0		155.0	324.0	50.0	28.5
Long-term Debt, Gross	0					92.5
Senior Notes due 2022 [Member]
Debt Instrument [Line Items]
Long-term Debt, Gross	600.0
Senior secured notes due 2018 [Member]
Debt Instrument [Line Items]
Debt Instrument, Repurchased Face Amount											325.0	175.0
Long-term Debt, Gross	0					325.0
Senior notes due 2019 [Member]
Debt Instrument [Line Items]
Debt Instrument, Repurchased Face Amount											234.7		541.4	25.0
Long-term Debt, Gross	503.9					1,305.0
Senior Notes due 2024 [Member]
Debt Instrument [Line Items]
Long-term Debt, Gross	$ 575.0