
(in thousands)
	2020		2019		2018

Current income tax expense	$	80,373	$	76,535	$	84,454
Deferred income tax (benefit) expense	(5,162)		3,349		(1,358)

Income tax expense	$	75,211	$	79,884	$	83,096

A reconciliation of the provision for income taxes, with amounts determined by applying the statutory federal income tax rate to pre-tax income, is as follows for the years ended December 31:


(in thousands)
	2020		2019		2018
Income tax at statutory rate	$	77,388	$	83,308	$	77,977

Tax-exempt interest	—		(123)		(1,305)


(Decrease) increase in unrecognized tax benefits	—		(3,088)		3,088
Other, net	(2,177)		(213)		3,336
Income tax expense	$	75,211	$	79,884	$	83,096

Temporary differences and carry-forwards, which give rise to deferred tax assets and liabilities, are as follows as of December 31:


(in thousands)
	2020		2019
Deferred tax assets:
Pension and other postretirement benefits	$	29,065	$	25,720
Other employee benefits	14,544		11,835
Deferred revenue	3,872		3,755
Allowance for management fee returned on cancelled policies	3,515		3,421


Unrealized losses on investments	1,083		—
Other	2,692		1,663
Total deferred tax assets	54,771		46,394
Deferred tax liabilities:
Depreciation	29,978		19,454
Unrealized gains on investments	7,540		4,181
Prepaid expenses	3,800		4,890

Commissions	884		545




Other	228		138
Total deferred tax liabilities	42,430		29,208
Net deferred tax asset	$	12,341	$	17,186

If we determine that any of our deferred tax assets will not result in future tax benefits, a valuation allowance must be established for the portion of the assets that are not expected to be realized. We had no valuation allowance recorded at December 31, 2020 or 2019.


(in thousands)
	2020		2019		2018
Balance at the beginning of the year	$	0	$	3,088	$	0
Additions for current year tax positions	—		—		7,719
Reductions for current year tax positions	—		—		(4,631)
Additions for prior year tax positions	—		4,631		—
Reductions for prior year tax positions	—		(7,719)		—
Balance at the end of the year	$	0	$	0	$	3,088

The uncertain tax position including $3.1 million of tax expense and $0.9 million of interest expense recorded in 2018 was settled during 2019. This settlement reduced our effective tax rate by 1.0% in 2019. The amounts recorded in 2018 resulted from the difference in measuring the tax liability at the previous tax rate and the current enacted tax rate. The recording of the uncertain tax position and related interest expense increased our 2018 effective tax rate by 1.0%.

Tax years ending December 31, 2019, 2018 and 2017 remain open to IRS examination. We are not currently under IRS audit, nor have we been notified of an upcoming IRS audit.

We are the attorney-in-fact for the subscribers (policyholders) at the Exchange, a reciprocal insurance exchange. In that capacity, we provide all services and facilities necessary to conduct the Exchange's insurance business. Indemnity and the Exchange together constitute a single insurance business. Consequently, we are not subject to state corporate income or franchise taxes in states where the Exchange conducts its business and the states collect premium tax in lieu of corporate income or franchise tax, as a result of the Exchange's remittance of premium taxes in those states.