Segment Information Schedule of Segment Reporting Information, by Segment (Tables)

12 Months Ended

Dec. 31, 2024

Segment Reporting [Abstract]

Schedule of Segment Reporting Information, by Segment

Summarized financial information concerning our reportable segments is shown in the following tables.

Year ended December 31, 2024	MD&E		IA&C		SC&E		Total
Total revenue	$	4,274.3	$	3,907.2	$	2,510.2	$	10,691.7
Revenue before billable expenses	4,213.8		3,544.4		1,429.4		9,187.6
Base salaries, benefits and tax	2,207.9		2,187.0		870.9
Incentive expense	128.4		95.6		33.1
Severance expense	65.8		58.9		13.8
Temporary help	85.3		142.9		45.7
Office and other direct expenses	751.8		420.4		170.9
Depreciation and amortization 1	106.1		50.6		14.3
Other segment items 2	81.1		409.2		1,102.1
Segment EBITA	$	847.9	$	542.6	$	259.4	$	1,649.9
Amortization of acquired intangibles	77.2		3.1		1.5
Impairment of goodwill	232.1		—		—
Capital expenditures	75.6		29.5		12.1

1 Excludes amortization of acquired intangibles.

2 Includes billable expenses, other salaries and related expenses and restructuring charges.

Year ended December 31, 2023	MD&E		IA&C		SC&E		Total
Total revenue	$	4,417.4	$	3,979.6	$	2,492.3	$	10,889.3
Revenue before billable expenses	4,348.6		3,611.1		1,440.9		9,400.6
Base salaries, benefits and tax	2,358.4		2,244.3		860.7
Incentive expense	124.4		84.9		43.3
Severance expense	55.8		53.1		15.0
Temporary help	104.4		154.0		52.4
Office and other direct expenses	739.3		438.0		165.2
Depreciation and amortization 1	105.8		53.6		15.9
Other segment items 2	92.4		414.9		1,074.6
Segment EBITA	$	836.9	$	536.8	$	265.2	$	1,638.9
Amortization of acquired intangibles	77.3		4.3		2.4
Capital expenditures	100.2		40.7		6.4

1 Excludes amortization of acquired intangibles.

2 Includes billable expenses, other salaries and related expenses and restructuring charges.

Year ended December 31, 2022	MD&E		IA&C		SC&E		Total
Total revenue	$	4,401.1	$	4,121.1	$	2,405.6	$	10,927.8
Revenue before billable expenses	4,315.7		3,747.5		1,386.2		9,449.4
Base salaries, benefits and tax	2,286.2		2,225.9		836.4
Incentive expense	158.0		139.8		44.2
Severance expense	31.6		36.6		10.2
Temporary help	135.4		203.6		51.8
Office and other direct expenses	751.2		427.9		167.3
Depreciation and amortization 1	107.5		58.3		16.9
Other segment items 2	182.8		451.5		1,044.3
Segment EBITA	$	748.4	$	577.5	$	234.5	$	1,560.4
Amortization of acquired intangibles	72.8		7.2		4.7
Capital expenditures	97.5		43.7		7.3

1 Excludes amortization of acquired intangibles.

2 Includes billable expenses, other salaries and related expenses and restructuring charges.

	December 31,
	2024		2023
Total assets:
MD&E	$	10,248.1	$	10,737.5
IA&C	4,549.9		4,790.4
SC&E	1,758.9		1,800.6
Corporate and other	1,768.9		1,938.8
Total	$	18,325.8	$	19,267.3

The following table presents the reconciliation of segment EBITA to Income before income taxes.

	Years ended December 31,
	2024		2023		2022
MD&E EBITA	$	847.9	$	836.9	$	748.4
IA&C EBITA	542.6		536.8		577.5
SC&E EBITA	259.4		265.2		234.5
Total segment EBITA	1,649.9		1,638.9		1,560.4
Corporate and other	(132.8)		(72.3)		(94.5)
Less: consolidated amortization of acquired intangibles	81.8		84.0		84.7
Less: impairment of goodwill	232.1		—		—
Operating income	1,203.2		1,482.6		1,381.2
Total (expenses) and other income	(154.1)		(74.6)		(112.3)
Income before income taxes	$	1,049.1	$	1,408.0	$	1,268.9