Income Taxes (Tables)

12 Months Ended

Dec. 31, 2011

Income Taxes [Abstract]

Provision for income taxes for income from continuing operations

	Year Ended December 31,
	2011		2010		2009
Current:
Federal	$	23,020	$	54,986	$	93,543
State		7,601		11,208		13,577
		30,621		66,194		107,120
Deferred:
Federal		105,771		92,628		16,012
State		1,261		4,859		18,719
		107,032		97,487		34,731
Total provision for income taxes for income from continuing operations	$	137,653	$	163,681	$	141,851

Differences between the statutory federal income tax rate and the effective tax rate

	Year Ended December 31,
	2011						2010						2009
	Amount			%			Amount			%			Amount			%
Provision for income taxes at statutory federal rate	$	165,741			35.0	%	$	181,474			35.0	%	$	156,682			35.0	%
State income taxes, net of federal income tax benefit		8,212			1.7			8,847			1.7			9,080			2.0
Release of unrecognized tax benefit		(6,509	)		(1.3	)		—			—			—			—
Net income attributable to noncontrolling interests		(26,486	)		(5.6	)		(23,960	)		(4.6	)		(22,006	)		(4.9	)
Change in valuation allowance		—			0.0			(910	)		(0.2	)		1,113			0.3
Federal and state tax credits		(3,788	)		(0.8	)		(2,246	)		(0.4	)		(4,241	)		(0.9	)
Deferred tax revaluation		—			—			—			—			(2,996	)		(0.7	)
Other		483			0.1			476			0.1			4,219			0.9
Provision for income taxes and effective tax rate for income from continuing operations	$	137,653			29.1	%	$	163,681			31.6	%	$	141,851			31.7	%

Components of deferred income taxes

	December 31,
	2011					2010
	Assets			Liabilities		Assets			Liabilities
Net operating loss and credit carryforwards	$	140,825		$	—	$	131,093		$	—
Property and equipment		—			727,366		—			685,089
Self-insurance liabilities		113,640			—		91,246			—
Intangibles		—			201,396		—			169,860
Investments in unconsolidated affiliates		—			62,112		—			48,353
Other liabilities		—			22,050		—			27,045
Long-term debt and interest		—			24,115		—			29,191
Accounts receivable		11,435			—		60,026			—
Accrued expenses		49,575			—		53,842			—
Other comprehensive income		128,170			—		156,597			—
Stock-based compensation		28,894			—		25,472			—
Deferred compensation		42,668			—		41,703			—
Other		57,158			—		24,963			—
		572,365			1,037,039		584,942			959,538
Valuation allowance		(150,254	)		—		(126,644	)		—
Total deferred income taxes	$	422,111		$	1,037,039	$	458,298		$	959,538

Reconciliation of the total amount of unrecognized tax benefit

	Year Ended December 31,
	2011			2010			2009
Unrecognized tax benefit, beginning of year	$	7,458		$	9,234		$	15,630
Gross (decreases) increases — purchase business combination		—			—			(4,173	)
Gross increases — tax positions in prior period		349			70			—
Reductions — tax positions in prior period		(3,469	)		(1,833	)		—
Lapse of statute of limitations		(3,575	)		—			(663	)
Settlements		(134	)		(13	)		(1,560	)
Unrecognized tax benefit, end of year	$	629		$	7,458		$	9,234