13.	Income taxes

The Company accounts for income taxes under the asset and liability method, which requires the recognition of deferred tax assets and liabilities for the expected future tax consequences of events that have been included in the financial statements. Under this method, deferred tax assets and liabilities are determined on the basis of the differences between the financial statements and tax basis of assets and liabilities using enacted tax rates in effect for the year in which the differences are expected to reverse.

Income tax expense (benefit) consisted of the following:

	Year ended December 31,
	2014		2013			2012
Current:
Federal	$	188,302	$	334,258		$	239,232
State		30,789		68,715			49,178
International		1,687		1,764			660
Total current income tax	$	220,778	$	404,737		$	289,070
Deferred:
Federal		192,267		(6,695	)		64,195
State		32,360		(8,941	)		6,498
International		938		746			—
Total deferred income tax	$	225,565	$	(14,890	)	$	70,693
	$	446,343	$	389,847		$	359,763

The allocation of income tax expense (benefit) was as follows:

	Year ended December 31,
	2014		2013			2012
Continuing operations	$	446,343	$	381,013		$	359,845
Discontinued operations		—		(84	)		(82	)
Gain on discontinued operations		—		8,918			—
	$	446,343	$	389,847		$	359,763

The reconciliation between the Company’s effective tax rate from continuing operations and the U.S. federal income tax rate is as follows:

	Year ended December 31,
	2014			2013			2012
Federal income tax rate		35.0	%		35.0	%		35.0	%
State income taxes, net of federal benefit		3.5			3.8			4.0
International rate differential		(0.2	)		0.1			—
Changes in deferred tax valuation allowances		0.6			0.3			—
Contingent earn-out adjustments		—			(2.6	)		—
Other		(0.8	)		1.4			1.1
Impact of noncontrolling interests primarily attributable to non-tax paying entities		(4.0	)		(4.1	)		(4.2	)
Effective tax rate		34.1	%		33.9	%		35.9	%

The Company has not recognized any deferred taxes for the undistributed earnings of its foreign subsidiaries because the Company currently expects those earnings to be permanently reinvested. Determination of the amount of unrecognized deferred taxes related to undistributed earnings of foreign subsidiaries is not practicable because such liability, if any, is dependent on circumstances that will exist if and when remittance occurs.

Deferred tax assets and liabilities arising from temporary differences associated with continuing operations were as follows:

	December 31,
	2014			2013
Receivables	$	42,973		$	49,667
Accrued liabilities		253,158			252,008
Loss contingency reserve		1,423			139,844
Net operating loss carryforwards		100,768			96,212
Other		88,435			67,882
Deferred tax assets		486,757			605,613
Valuation allowance		(26,667	)		(13,860	)
Net deferred tax assets		460,090			591,753
Intangible assets		(835,816	)		(752,838	)
Property and equipment		(187,054	)		(183,059	)
Investments in partnerships		(78,618	)		(51,921	)
Other		(8,677	)		(6,913	)
Deferred tax liabilities		(1,110,165	)		(994,731	)
Net deferred tax liabilities	$	(650,075	)	$	(402,978	)

At December 31, 2014, the Company had federal net operating loss carryforwards of approximately $203,282 that expire through 2034, although a substantial amount expire by 2028. The Company also had state net operating loss carryforwards of $568,286 that expire through 2034 and international net operating loss carryforwards of $55,436, some of which have an indefinite life. The utilization of a portion of these losses may be limited in future years based on the profitability of certain entities. The valuation allowance increase of $12,807 is primarily due to the realizability of losses in certain foreign and state jurisdictions.

Unrecognized tax benefits

A reconciliation of the beginning and ending liability for unrecognized tax benefits that do not meet the more-likely-than-not threshold were as follows:

	Year ended December 31,
		2014			2013
Balance beginning	$	60,538		$	67,546
Additions for tax positions related to current year		914			6,005
Reductions for tax positions related to prior years		(27,312	)		(3,901	)
Reductions related to lapse of applicable statute		(2,077	)		(8,480	)
Reductions related to settlements with taxing authorities		(186	)		(632	)
Balance ending	$	31,877		$	60,538

As of December 31, 2014, the Company’s total liability for unrecognized tax benefits relating to tax positions that do not meet the more-likely-than-not threshold is $31,877, all of which would impact the Company’s effective tax rate if recognized. This balance represents a decrease of $28,661 from the December 31, 2013 balance of $60,538, of which $27,427 is due to a change of accounting method for income tax reporting and did not impact the Company’s effective tax rate.

The Company recognizes accrued interest and penalties related to unrecognized tax benefits in its income tax expense. At December 31, 2014 and 2013, the Company had approximately $10,123 and $10,742, respectively, accrued for interest and penalties related to unrecognized tax benefits, net of federal tax benefit.

The Company and its subsidiaries file U.S. federal and state income tax returns and various international income tax returns. The Company is no longer subject to U.S. federal and state examinations by tax authorities for years before 2011 and 2008, respectively.