Debt (Tables)

12 Months Ended

Dec. 31, 2011

Debt [Abstract]

Long Term Debt Instruments

		December 31,
Description	Maturity Date	2011			2010
Credit facility	August 2016	$	60.0		$	—
7.625% senior notes	February 2017		150.0			150.0
New 4.0% Notes, $105.3 million principal amount	June 2014		98.2			—
New 4.25% Notes, $97.0 million principal amount	December 2014		89.9			—
Original 4.0% Notes	June 2014		9.7			115.0
Original 4.25% Notes	December 2014		3.0			100.0
3.5267% equipment term loan	In installments through 2013		8.3			12.9
Capital lease obligations, weighted average interest rate of 3.7%	In installments through 2017		40.6			24.5
Notes payable for equipment, weighted average interest rate of 3.5%	In installments through 2015		35.2			10.2
Total debt		$	494.9		$	412.6
Less current maturities			(34.2	)		(18.4	)
Long-term debt		$	460.7		$	394.2

Schedule Of Convertible Notes Carrying Amount Details

	December 31, 2011
	New 4.0%  Senior Convertible Notes			New 4.25% Senior Convertible Notes
Principal amount	$	105.3		$	97.0
Unamortized debt discount		(6.7	)		(6.7	)
Unamortized balance of investor fees		(0.4	)		(0.4	)
Net carrying amount of debt component	$	98.2		$	89.9
Carrying amount of equity component	$	8.9		$	8.5

Schedule Of Maturities Of Debt And Capital Leases

2012	$	34.2
2013		36.7
2014		209.9
2015		3.7
2016		60.4
Thereafter		150.0
Total	$	494.9

Schedule Of Interest Expense, Net

	Year Ended December 31,
	2011			2010			2009
Interest expense:
Contractual interest payments and other interest expense	$	27.5		$	27.0		$	23.8
Senior convertible note discount and related investor fee accretion		4.2			—			—
Amortization of deferred financing costs		3.3			3.3			2.1
Total interest expense	$	35.0		$	30.3		$	25.9
Interest income		(0.6	)		(1.2	)		(1.2	)
Interest expense, net	$	34.4		$	29.1		$	24.7