Segment Information (Tables)

12 Months Ended

Dec. 31, 2023

Segment Reporting [Abstract]

Summarized Financial Information Reportable Segments

Summarized financial information concerning the Company’s reportable segments is shown in the following table. The “Other” column includes any income and expenses not allocated to reportable segments and corporate-related items, including the intercompany interest expense charge to the reporting segment.

	Year Ended December 31, 2023
(in millions)	Retail		National Programs		Wholesale Brokerage		Services		Other			Total
Total revenues	$	2,440.0	$	1,077.3	$	540.7	$	163.1	$	36.0		$	4,257.1
Investment income	$	1.3	$	12.1	$	1.5	$	—	$	37.5		$	52.4
Amortization	$	108.5	$	41.2	$	11.2	$	5.1	$	—		$	166.0
Depreciation	$	18.0	$	11.8	$	2.6	$	1.4	$	6.2		$	40.0
Interest expense	$	83.4	$	35.6	$	11.9	$	1.3	$	57.8		$	190.0
Income before income taxes	$	528.4	$	405.5	$	125.8	$	153.8	$	(67.4	)	$	1,146.1
Total assets	$	8,303.9	$	4,333.5	$	1,558.9	$	209.0	$	478.1		$	14,883.4
Capital expenditures	$	45.5	$	16.5	$	3.0	$	1.1	$	2.8		$	68.9

	Year Ended December 31, 2022
(in millions)	Retail		National Programs		Wholesale Brokerage		Services		Other			Total
Total revenues	$	2,084.3	$	859.5	$	453.4	$	171.9	$	4.3		$	3,573.4
Investment income	$	0.1	$	1.3	$	0.3	$	—	$	4.8		$	6.5
Amortization	$	96.7	$	35.4	$	9.4	$	5.1	$	—		$	146.6
Depreciation	$	12.8	$	15.3	$	2.7	$	1.6	$	6.8		$	39.2
Interest expense	$	94.3	$	33.0	$	12.9	$	2.1	$	(1.1	)	$	141.2
Income before income taxes	$	466.7	$	271.1	$	117.7	$	24.1	$	(3.5	)	$	876.1
Total assets	$	7,458.6	$	4,467.8	$	1,401.6	$	295.0	$	350.5		$	13,973.5
Capital expenditures	$	18.6	$	20.2	$	2.8	$	1.0	$	10.0		$	52.6

	Year Ended December 31, 2021
(in millions)	Retail		National Programs		Wholesale Brokerage		Services		Other			Total
Total revenues	$	1,767.9	$	701.9	$	403.4	$	178.9	$	(0.7	)	$	3,051.4
Investment income	$	0.3	$	0.6	$	0.2	$	—	$	—		$	1.1
Amortization	$	77.8	$	27.4	$	9.1	$	5.3	$	—		$	119.6
Depreciation	$	11.2	$	9.8	$	2.6	$	1.5	$	8.2		$	33.3
Interest expense	$	91.4	$	11.4	$	16.0	$	2.9	$	(56.7	)	$	65.0
Income before income taxes	$	334.4	$	242.3	$	94.8	$	28.3	$	63.0		$	762.8
Total assets	$	5,040.7	$	2,943.0	$	1,154.4	$	299.2	$	358.1		$	9,795.4
Capital expenditures	$	8.1	$	13.5	$	1.6	$	1.6	$	20.2		$	45.0