Notes Payable and Indebtedness - Borrowings (Details) $ in Millions	9 Months Ended
	Sep. 30, 2023 USD ($)	Dec. 31, 2022 USD ($)
Debt maturing within one year:
Principal amount	$ 32.7	$ 32.7
Debt issuance costs and discount	0.0	0.0
Carrying value	32.7	32.7
Debt maturing after one year:
Principal amount	3,653.7	3,613.9
Debt issuance costs and discount	47.8	61.7
Carrying value	3,605.9	3,552.2
Total debt
Principal amount	3,686.4	3,646.6
Debt issuance costs and discount	47.8	61.7
Carrying value	3,638.6	3,584.9
2026 Term Loan | Line of Credit | Secured Debt
Debt maturing within one year:
Principal amount	28.1	28.1
Debt issuance costs and discount	0.0	0.0
Carrying value	28.1	28.1
Debt maturing after one year:
Principal amount	2,630.6	2,651.7
Debt issuance costs and discount	36.8	49.2
Carrying value	2,593.8	2,602.5
2029 Term Loan | Line of Credit | Secured Debt
Debt maturing within one year:
Principal amount	4.6	4.6
Debt issuance costs and discount	0.0	0.0
Carrying value	4.6	4.6
Debt maturing after one year:
Principal amount	448.5	451.9
Debt issuance costs and discount	5.6	6.5
Carrying value	442.9	445.4
Revolving facility | Line of Credit | Revolving Credit Facility
Debt maturing after one year:
Principal amount	114.6	50.3
Debt issuance costs and discount	0.0	0.0
Carrying value	$ 114.6	$ 50.3
Total debt
Maximum ratio of first lien net indebtedness to consolidated EBITDA	6.75
Applicable threshold for maximum ratio of first lien net indebtedness to consolidated EBITDA (as a percent)	35.00%
5.000% Senior Unsecured Notes | Unsecured Debt
Total debt
Interest rate on debt instrument (as a percent)	5.00%	5.00%
5.000% Senior Unsecured Notes | Unsecured Debt Excluding Current Maturities
Debt maturing after one year:
Principal amount	$ 460.0	$ 460.0
Debt issuance costs and discount	5.4	6.0
Carrying value	$ 454.6	$ 454.0