Income Taxes (Tables)

12 Months Ended

Dec. 31, 2011

Income Taxes [Abstract]

Schedule Of Components Of Income Tax Expense/(Benefit)

	Year Ended December 31,
	2011		2010		2009
Current
Federal	$	165,409	$	105,077	$	130,798
Foreign		300		2,555		—
State		22,901		16,547		18,976
		188,610		124,179		149,774
Deferred
Federal and foreign		53,056		26,419		18,524
State		5,800		1,704		2,177
		58,856		28,123		20,701
Total	$	247,466	$	152,302	$	170,475

Schedule Of Components Of Deferred Taxes

	Year Ended December 31,
	2011			2010
Deferred income tax assets:
Self-insurance reserves	$	115,201		$	121,249
Compensation accruals		49,717			53,855
State and foreign net operating loss carryforwards and other state and foreign deferred tax assets		52,506			46,338
Other currently non-deductible accrued liabilities		19,699			19,016
Net pension liability—OCI only		13,959			9,268
Doubtful accounts and other reserves		17,345			31,046
Other combined items—OCI only		17,684			3,196
		286,111			283,968
Less: Valuation Allowance		(42,143	)		(32,352	)
Net deferred income tax assets:		243,968			251,616
Deferred income tax liabilities:
Depreciable and amortizable assets		(342,655	)		(299,566	)
Other deferred tax liabilities		(2,581	)		(4,570	)
Net deferred income tax liabilities	$	(101,268	)	$	(52,520	)

Schedule Of Effective Tax Rates Calculation

	2011			2010			2009
Provision for income taxes	$	247,466		$	152,302		$	170,475
Income before income taxes		696,336			428,097			474,722
Effective tax rate		35.5	%		35.6	%		35.9	%

Schedule Of Reconciliation Between Federal Statutory Rate And Effective Tax Rate

	Year Ended December 31,
	2011			2010			2009
Federal statutory rate		35.0	%		35.0	%		35.0	%
State taxes, net of federal income tax benefit		2.9			3.1			3.2
Nondeductible transaction costs		—			1.3			—
Other items		0.4			0.4			1.4
Impact of income attributable to noncontrolling interests		(2.8	)		(4.2	)		(3.7	)
Effective tax rate		35.5	%		35.6	%		35.9	%

Schedule Of Net Deferred Tax Assets And Liabilities

	Year Ended December 31,
	2011			2010
Current deferred taxes
Assets	$	109,297		$	123,362
Liabilities		(973	)		(2,528	)
Total deferred taxes-current		108,324			120,834
Noncurrent deferred taxes
Assets		135,189			128,254
Liabilities		(344,781	)		(301,608	)
Total deferred taxes-noncurrent		(209,592	)		(173,354	)
Total deferred tax liabilities	$	(101,268	)	$	(52,520	)

Schedule Of Reconciliation Of Unrecognized Tax Benefits

	As of December 31,
	2011			2010			2009
Balance at January 1,	$	7,923		$	5,754		$	3,759
Additions based on tax positions related to the current year		750			1,219			750
Additions for tax positions of prior years		419			2,076			1,245
Reductions for tax positions of prior years		(1,628	)		(907	)		—
Settlements		(61	)		(219	)		—
Balance at December 31,	$	7,403		$	7,923		$	5,754