Debt (Tables)

3 Months Ended

Mar. 31, 2013

Debt Instrument [Line Items]

Schedule of Long Term Debt Instruments

The following table, which may contain summation differences due to rounding, provides details of the carrying value of debt as of the dates indicated (in millions):

Description	Maturity Date	March 31, 2013			December 31, 2012
Credit facility	August 22, 2016	$	—		$	134.0
4.875% senior notes	March 15, 2023	400.0			—
7.625% senior notes	February 1, 2017	—			150.0
New 4.0% Notes, $105.3 million principal amount	June 15, 2014	101.6			100.9
New 4.25% Notes, $97.0 million principal amount	December 15, 2014	92.7			92.1
Original 4.0% Notes	June 15, 2014	9.6			9.7
Original 4.25% Notes	December 15, 2014	3.0			3.0
Capital lease obligations, weighted average interest rate of 2.9%	In installments through January 2020	94.3			79.0
Notes payable for equipment, weighted average interest rate of 2.8%	In installments through June 2018	33.4			30.2
Total debt		$	734.7		$	598.9
Less current maturities		(49.3		)	(52.6		)
Long-term debt		$	685.4		$	546.3

Schedule of Interest Expense, Net

The following table, which may contain summation differences due to rounding, provides details of interest expense, net, classified within continuing operations for the periods indicated (in millions):

	For the Three Months Ended March 31,
	2013			2012
Interest expense:
Contractual and other interest expense	$	7.6		$	6.5
Accretion of senior convertible note discount	1.3			1.2
Amortization of deferred financing costs and commitment fees	1.3			1.4
Total interest expense	$	10.1		$	9.1
Interest income	(0.1		)	(0.1		)
Interest expense, net	$	10.0		$	9.0

Total New Senior Convertible Notes [Member]

Debt Instrument [Line Items]

Schedule of Convertible Notes, Carrying Amount Details

The carrying values of the debt and equity components of the New Convertible Notes as of the dates indicated are as follows (in millions):

	March 31, 2013
	New 4.0% Senior Convertible Notes			New 4.25% Senior Convertible Notes
Principal amount	$	105.3		$	97.0
Unamortized debt discount and financing costs	(3.7		)	(4.3		)
Net carrying amount of debt component	$	101.6		$	92.7
Carrying amount of equity component	$	8.9		$	8.5