Debt Debt - New Tranche B Term Loan Facility (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended			3 Months Ended								3 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012	Sep. 30, 2013 London Interbank Offered Rate (LIBOR) [Member]	Sep. 30, 2013 Base Rate [Member]	Sep. 30, 2013 Federal Funds Rate [Member]	Sep. 30, 2013 Tranche B Term Loan [Member]	Dec. 31, 2013 Senior Notes due 2017 [Member]	Oct. 15, 2013 Senior Notes due 2017 [Member]	Sep. 30, 2013 Senior Notes due 2017 [Member]	Dec. 31, 2012 Senior Notes due 2017 [Member]	Sep. 30, 2013 London Interbank Offered Rate (LIBOR) [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount									$ 540.0		$ 500.0
Original Issue Discount, Tranche B Term Loan		0.75%	0.75%
Required Principal Payments, Tranche B Term Loan		0.25%
LIBOR rate floor						1.00%
Debt Instrument, Basis Spread on Variable Rate						1.00%	2.00%	0.50%						3.00%
Issuance of long-term debt			536.0	0					529.6
Redemption price	104.125%
Accrued interest											20.6
Debt extinguishment loss	29.6
Debt extinguishment, call premiums	20.6
Write-off of debt issuance costs										5.3
Write-off of debt discount											3.7	(3.7)	0
Restricted payments, limit when leverage ratio threshold not attained		15	15
Restricted payments, limit when leverage ratio threshold is attained		45	45
Leverage Ratio, threshold		3.50	3.50
Leverage Ratio, threshold, other		3.00	3.00
Restricted Payments, Share Repurchases or Dividends, limit		15.00%	15.00%
Restricted Payments, Share Repurchases or Dividends, cap		35	35
Proceeds from Sale of Equity Method Investment, Percent Required for Mandatory Debt Prepayments		85.00%	85.00%		100.00%
Line of Credit Facility, Amount Outstanding		0	0
Line of Credit Facility, Remaining Borrowing Capacity		$ 200.0	$ 200.0