Income Taxes (Tables)

12 Months Ended

Dec. 31, 2022

Income Tax Disclosure [Abstract]

Summary of Provision for Income Tax Expense (Benefit)

The provision for income tax expense consisted of the following:

	(In thousands) Years Ended December 31,
	2022		2021		2020
Current tax expense
Federal	$	12,902	$	31,171	$	2,525
State	1,023		2,829		(459)
	13,925		34,000		2,066
Deferred tax (benefit) expense
Federal	(8,624)		107		1,294
State	(768)		841		(553)
	(9,392)		948		741
Income tax expense	$	4,533	$	34,948	$	2,807

Summary of Deferred Tax Assets (Liabilities)

Deferred tax (liabilities) assets were comprised of the following:

	(In thousands) December 31,
	2022		2021
Deferred tax assets:
Accrued expenses	$	627	$	620
Allowance for doubtful accounts	152		269
Contract overrun reserves	952		680
Deferred compensation	234		272
Deferred revenue	943		1,570
Employment-related accruals	3,932		4,028
Environmental reserves	501		499
Federal tax credit carryforwards	133		133
Inventory reserves	3,572		2,957
Operating lease liabilities	8,672		8,145
Pension obligation	28		1,550
Federal and state net operating loss carryforwards	3,397		4,243
Research expenses	10,620		—
State tax credit carryforwards	6,974		7,123
Stock-based compensation	2,420		2,584
Other	1,525		2,503
Total gross deferred tax assets	44,682		37,176
Valuation allowance	(7,548)		(7,718)
Total gross deferred tax assets, net of valuation allowance	37,134		29,458
Deferred tax liabilities:
Depreciation	(11,286)		(11,986)
Goodwill	(8,630)		(6,557)
Intangibles	(18,310)		(20,337)
Interest rate hedge	(3,359)		—
Operating lease right-of-use assets	(8,346)		(7,931)
Prepaid insurance	(609)		(534)
Other	(547)		(840)
Total gross deferred tax liabilities	(51,087)		(48,185)
Net deferred tax liabilities	$	(13,953)	$	(18,727)

Principle Reasons for Variation Between Expected and Effective Tax Rate

The principal reasons for the variation between the statutory and effective tax rates were as follows:

	Years Ended December 31,
	2022	2021	2020
Statutory federal income tax rate	21.0%	21.0%	21.0%
State income taxes (net of federal benefit)	4.0	3.1	4.6
Foreign derived intangible income deduction	(0.9)	—	(0.4)
Stock-based compensation expense	(0.6)	(0.5)	(1.4)
Research and development tax credits (1)	(14.8)	(3.0)	(13.8)
Other tax credits	(0.1)	—	(0.3)
Changes in valuation allowance	(0.5)	(1.0)	(0.4)
Non-deductible book compensation expenses	4.4	0.7	3.3
Changes in deferred tax assets	(0.2)	—	(0.2)
Changes in tax reserves	—	0.2	(4.6)
Other	1.3	—	1.0
Effective income tax rate	13.6%	20.5%	8.8%

(1)For 2020, (3.4)% is additional research and development tax credits related to 2019.

Reconciliation of Unrecognized Tax Benefits

A reconciliation of the beginning and ending amount of unrecognized tax benefits was as follows:

	(In thousands) Years Ended December 31,
	2022		2021		2020
Balance at January 1,	$	4,435	$	4,069	$	5,663
Additions for tax positions related to the current year	1,177		562		418
Additions for tax positions related to prior years	15		180		157
Reductions for tax positions related to prior years	(13)		—		—
Reductions for lapse of statute of limitations	(670)		(376)		(2,169)
Balance at December 31,	$	4,944	$	4,435	$	4,069