Income Taxes (Tables)

12 Months Ended

Dec. 31, 2014

Income Taxes

Schedule of components of provision (benefit) for income taxes

Years ended December 31,	2014		2013			2012
(in thousands)
Current provision:
Federal	$	119,074	$	104,890		$	147,580
State		19,858		15,627			14,673
Foreign		2,907		1,918			1,109
Deferred provision (benefit):
Federal		11,514		(12,025	)		5,027
State		840		(1,035	)		(206	)
Total income tax provision	$	154,193	$	109,375		$	168,183

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

Years ended December 31,	2014			2013			2012
Federal statutory rate		35.0	%		35.0	%		35.0	%
State income taxes, net of federal benefit		3.3			3.8			3.2
Tax credits		(0.7	)		(0.3	)		(0.3	)
Non-deductible expenses		0.4			0.5			0.5
Other		0.6			0.6			(0.4	)
Effective tax rate		38.6	%		39.6	%		38.0	%

Schedule of deferred tax assets and liabilities

December 31,	2014			2013
(in thousands)
Deferred tax assets:
Self-insurance	$	7,675		$	7,247
Pension		12,555			8,018
State net operating loss carryforwards		451			484
Bad debts		5,755			4,748
Accrued payroll		2,833			2,019
Stock-based compensation		5,583			5,183
Tangible property regulations 481(a)		—			7,665
All others		2,121			1,541
Valuation allowance		(2	)		(83	)
Gross deferred tax assets		36,971			36,822
Deferred tax liabilities:
Depreciation		(172,813	)		(165,960	)
Goodwill amortization		(7,974	)		(7,094	)
All Others		(3,739	)		(2,759	)
Gross deferred tax liabilities		(184,526	)		(175,813	)
Net deferred tax liabilities	$	(147,555	)	$	(138,991	)

Schedule of reconciliation of the beginning and ending amount of unrecognized tax benefits

	2014		2013
Balance at January 1	$	16,345,000	$	38,000
Additions based on tax positions related to the current year		5,193,000		3,430,000
Additions for tax positions of prior years		1,729,000		12,877,000
Balance at December 31	$	23,267,000	$	16,345,000