Income Tax Matters, Effective Tax Rate Reconciliation (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Reconciliation between income tax provision and statutory income tax provision:
Amount of federal income tax provision based on the statutory rate	$ (50.1)		$ (48.9)		$ (14.5)
Decrease in federal valuation allowances	0.1		0.1		0
Non-deductible compensation expense	(0.3)		(0.4)		(1.1)
Non-deductible expense	(0.9)		(0.3)		(0.4)
State income taxes, net of federal benefit	(4.4)	[1]	(3.8)	[1]	(0.8)	[1]
Foreign income tax (expense) benefit	0		(0.5)		0.6
Expiration of statute of limitations	4.6		0		0
Settlement with taxing authorities	4.4		0		0
Advance pricing agreement	2.9		0		0
Competent Authority settlement	5.3		0		0
Income tax provision	(38.4)		(53.8)		(16.2)
Valuation Allowance
Increase (Decrease) in valuation allowance	1.2		(0.1)		(1.3)
Unused state net operating losses
Valuation Allowance
Increase (Decrease) in valuation allowance	$ 1.2				$ (1.2)

[1] State income taxes of $4.4 in 2013 includes a $1.2 increase in the valuation allowance relating to certain unused state net operating losses expected to expire. State income taxes of $0.8 in 2011 includes a $1.2 decrease in the valuation allowance relating to certain state net operating losses expected to be utilized before their expiration.