Income Taxes (Tables)

12 Months Ended

Dec. 31, 2012

Income Taxes

Schedule of components of provision (benefit) for income taxes

Years ended December 31,	2012			2011		2010
(in thousands)
Current provision:
Federal	$	147,580		$	91,415	$	56,289
State		14,673			12,938		11,180
Foreign		1,109			1,007		1,059
Deferred provision (benefit):
Federal		5,027			70,599		22,833
State		(206	)		6,475		(571	)
Total income tax provision	$	168,183		$	182,434	$	90,790

Schedule of reconciliation between the federal statutory rate and effective tax rate

Years ended December 31,	2012			2011			2010
Federal statutory rate		35.0	%		35.0	%		35.0	%
State income taxes, net of federal benefit		3.2			3.1			2.9
Tax credits		(0.3	)		(0.2	)		(0.6	)
Non-deductible expenses		0.5			0.4			0.4
Other		(0.4	)		(0.2	)		0.5
Effective tax rate		38.0	%		38.1	%		38.2	%

Schedule of deferred tax assets and liabilities

December 31,	2012			2011
(in thousands)
Deferred tax assets:
Self-insurance	$	7,417		$	6,344
Pension		9,688			8,922
State net operating loss carry forwards		1,165			1,671
Bad debts		3,489			3,044
Accrued payroll		2,038			2,099
Stock-based compensation		4,567			3,680
All others		274			1
Valuation allowance		(1,003	)		(1,295	)
Gross deferred tax assets		27,635			24,466
Deferred tax liabilities:
Depreciation		(168,717	)		(166,190	)
Goodwill amortization		(6,394	)		(5,707	)
All others		(1,754	)		(1,314	)
Gross deferred tax liabilities		(176,865	)		(173,211	)
Net deferred tax liabilities	$	(149,230	)	$	(148,745	)