	Year Ended December 31,
	2020			2019			2018
Current taxes:
Federal	$	143,859		$	123,802		$	89,971
State		42,705			30,464			36,070
Foreign		(236	)		1,684			99
		186,328			155,950			126,140
Deferred taxes:
Federal		(31,019	)		(7,027	)		11,932
State		(5,803	)		4,266			2,267
Foreign		(1,818	)		(4,037	)		55
		(38,640	)		(6,798	)		14,254
Provision for income taxes	$	147,688		$	149,152		$	140,394

Reconciliation of the statutory federal income tax rate with our company’s effective income tax rate is as follows (in thousands):

	Year Ended December 31,
	2020			2019			2018
Statutory rate	$	136,744		$	125,485		$	112,215
State income taxes, net of federal income tax		27,934			28,333			30,762
Change in uncertain tax position		666			2,661			(617	)
Foreign tax rate difference		(2,032	)		(629	)		(318	)
Excess tax benefit from stock-based compensation		(21,605	)		(9,670	)		(3,700	)
Revaluation of deferred tax assets		—			—			(3,006	)
Other, net		5,981			2,972			5,058
	$	147,688		$	149,152		$	140,394

Tax effect of temporary differences and carryforwards that comprise significant portions of deferred tax assets and liabilities (in thousands):

	December 31,
	2020			2019
Deferred tax assets:
Lease liabilities	$	211,524		$	181,607
Deferred compensation		79,068			80,389
Accrued expenses		73,835			26,166
Receivable reserves		41,963			33,199
Net operating loss carryforwards		32,727			28,781
Other		3,311			3,210
Total deferred tax assets		442,428			353,352
Valuation allowance		(11,740	)		(5,042	)
		430,688			348,310
Deferred tax liabilities:
Lease ROU asset		(210,670	)		(180,598	)
Goodwill and other intangibles		(51,189	)		(46,625	)
Depreciation		(15,371	)		(7,231	)
Unrealized gain on investments		(11,585	)		(5,619	)
Prepaid expenses		(5,396	)		(3,857	)
		(294,211	)		(243,930	)
Net deferred tax asset	$	136,477		$	104,380

Our net deferred tax asset at December 31, 2020, includes net operating loss carryforwards of $226.2 million that expire between 2024 and 2040. Certain of our net operating loss carryforwards do not expire. A valuation allowance is recorded to the extent that it is more likely than not that any portion of the deferred tax asset will not be realized. The valuation allowance was increased by $6.7 million.

We believe the realization of the remaining net deferred tax asset of $136.5 million is more likely than not based on the ability to carry back losses against prior year taxable income for tax years before 2021 and carry forward net operating losses indefinitely after 2021, and expectations of future taxable income, which is supported by a history of cumulative income.

The current tax payable, included in accounts payable and accrued expenses, is $38.2 million and $15.0 million as of December 31, 2020 and 2019, respectively. At December 31, 2020 and 2019, the Company did not have a tax receivable.

As of December 31, 2020, we considered all undistributed earnings of non-U.S. subsidiaries to be permanently reinvested. Therefore, we have not provided for any U.S. deferred income taxes. Because the time or manner of repatriation is uncertain, we cannot determine the impact of local taxes, withholding taxes and foreign tax credits associated with the future repatriation of such earnings, and therefore cannot quantify the tax liability that would be payable in the event all such foreign earnings are repatriated.

As of December 31, 2020 and 2019, we had $4.0 million and $3.4 million, respectively, of gross unrecognized tax benefits, all of which, if recognized, would impact the effective tax rate. We recognize interest and penalties related to uncertain tax positions in provision for income taxes in the consolidated statements of operations. As of December 31, 2020 and 2019, we had accrued interest and penalties of $0.4 million and $0.2 million, respectively, before benefit of federal tax deduction, included in accounts payable and accrued expenses in our consolidated statements of financial condition. The amount of interest and penalties recognized in our consolidated statements of operations for the years ended December 31, 2020, 2019, and 2018, was not significant.

The following table summarizes the activity related to our company’s unrecognized tax benefits from January 1, 2018 to December 31, 2020 (in thousands):

	Year Ended December 31,
	2020			2019			2018
Beginning balance	$	3,387		$	312		$	3,180
Increase related to prior year tax positions		977			2,173			4
Decrease related to prior year tax positions		(11	)		(54	)		(33	)
Increase related to current year tax positions		790			956			191
Decrease related to settlements with taxing authorities		(1,181	)		—			(3,030	)
Ending balance	$	3,962		$	3,387		$	312

We file income tax returns with the U.S. federal jurisdiction, various states, and certain foreign jurisdictions. We are not subject to U.S. federal examination for taxable years before 2013. We are not subject to certain state and local, or non-U.S. income tax examinations for taxable years before 2010.

There is a reasonable possibility that the unrecognized tax benefits will change within the next 12 months as a result of the expiration of various statutes of limitations or for the resolution of U.S. federal and state examinations, but we do not expect this change to be material to the consolidated financial statements.