Income taxes (Tables)

12 Months Ended

Dec. 31, 2023

Income Tax Disclosure [Abstract]

Schedule of Provision (Benefit) for Income Taxes on Income Consists

The provision (benefit) for income taxes consists of the following (in thousands):

2023	Current		Deferred		Total
Federal	$	96,816	$	14,240	$	111,056
State and other	13,646		5,497		19,143
Total	$	110,462	$	19,737	$	130,199

2022	Current		Deferred		Total
Federal	$	161,438	$	13,435	$	174,873
State and other	23,456		4,041		27,497
Total	$	184,894	$	17,476	$	202,370

2021	Current		Deferred		Total
Federal	$	114,255	$	15,400	$	129,655
State and other	11,310		(5,484)		5,826
Total	$	125,565	$	9,916	$	135,481

Schedule of Reconciliation of Effective Tax Rate

The provision for income taxes varies from the U.S. federal statutory tax rate as a result of the following differences:

	2023	2022	2021
U.S. statutory tax rate	21.0%	21.0%	21.0%
Increase (decrease) in taxes resulting from:
State taxes (net of federal income tax benefit)	2.3	2.7	2.6
Uncertain tax positions, settlements and lapse of statutes of limitations	(0.2)	—	0.3
Valuation allowance on equity method investment	(0.7)	0.6	—
Other valuation allowances, tax rate changes, & deferred adjustments	0.8	(0.6)	(1.7)
Non-deductible transaction costs	(0.8)	0.5	0.1
Net excess benefits or expense on share-based payments	(0.1)	(0.3)	(0.2)
Non-taxable Merger termination fee	(1.3)	—	—
Other, net	0.5	0.4	—
Effective tax rate	21.5%	24.3%	22.1%

Schedule of Deferred Tax Liabilities and Assets

Deferred tax liabilities and assets were composed of the following as of December 31, 2023 and 2022 (in thousands):

	Dec. 31,
	2023		2022
Deferred tax liabilities
Accelerated amortization of deductible intangibles	$	561,741	$	540,260
Accelerated depreciation	65,247		67,278
Right-of-use assets for operating leases	18,361		19,467
Other	4,024		4,183
Total deferred tax liabilities	649,373		631,188
Deferred tax assets
Accrued compensation costs	22,450		23,439
Pension and post-retirement medical and life	18,839		20,775
Loss carryforwards	16,435		12,537
Operating lease liabilities	19,443		20,403
Other	18,988		24,242
Total deferred tax assets	96,155		101,396
Deferred tax asset valuation allowance	25,001		26,339
Total net deferred tax liabilities	$	578,219	$	556,131

The following table summarizes the activity related to deferred tax asset valuation allowances (in thousands):

	2023		2022		2021
Beginning at beginning of period	$	26,339	$	41,929	$	43,467
Additions to valuation allowance	5,001		7,228		6,108
Reductions to valuation allowance	(6,339)		(22,818)		(7,646)
Balance at the end of the period	$	25,001	$	26,339	$	41,929

Schedule of Activity Related to Unrecognized Tax Benefits, Excluding Federal Tax Benefit of State Tax Deductions

The following table summarizes the activity related to unrecognized tax benefits, excluding the federal tax benefit of state tax deductions (in thousands):

	2023		2022		2021
Change in unrecognized tax benefits
Balance at beginning of year	$	7,725	$	8,196	$	7,435
Additions for tax positions of prior years	151		—		1,363
Reductions for tax positions of prior years	(680)		—		—
Settlements	—		(9)		—
Reductions due to lapse of statutes of limitations	(551)		(462)		(602)
Balance as of end of year	$	6,645	$	7,725	$	8,196