Debt (Tables)

3 Months Ended

Mar. 31, 2014

Debt Disclosure [Abstract]

Schedule of Long Term Debt Instruments

The following table provides details of the carrying values of debt as of the dates indicated (in millions):

Description	Maturity Date	March 31, 2014			December 31, 2013
Credit facility	October 29, 2018	$	128.6		$	53.0
4.875% senior notes	March 15, 2023	400.0			400.0
2011 4.0% senior convertible notes	June 15, 2014	104.6			103.8
2011 4.25% senior convertible notes	December 15, 2014	95.1			94.5
2009 4.0% senior convertible notes	June 15, 2014	9.6			9.6
2009 4.25% senior convertible notes	December 15, 2014	3.0			3.0
Capital lease obligations, weighted average interest rate of 2.9%	In installments through March 30, 2020	123.2			126.0
Notes payable for equipment, weighted average interest rate of 3.0%	In installments through May 1, 2018	30.1			26.9
Total debt		$	894.2		$	816.8
Less current maturities		(52.9		)	(51.4		)
Long-term debt		$	841.3		$	765.4

Schedule of Interest Expense, Net

The following table provides details of interest expense, net, for the periods indicated (in millions):

	For the Three Months Ended March 31,
	2014		2013
Interest expense:
Contractual and other interest expense	$	9.7	$	7.9
Accretion of senior convertible note discount	1.4		1.3
Amortization of deferred financing costs	0.9		0.9
Total interest expense	$	12.0	$	10.1
Interest income	0.0		(0.1		)
Interest expense, net	$	12.0	$	10.0