Debt and Credit Facilities (Narrative) (Details) - USD ($) $ in Millions	1 Months Ended	6 Months Ended
	Jul. 31, 2023	Jun. 30, 2023	Dec. 31, 2022
Debt Instrument [Line Items]
Total borrowings outstanding		$ 2,070.4	$ 2,106.7
Line of Credit
Debt Instrument [Line Items]
Interest rate		6.292%
Line of Credit | Bloomberg Short-Term Bank Yield Index
Debt Instrument [Line Items]
Variable rate		1.125%
Line of Credit | Minimum
Debt Instrument [Line Items]
Variable rate		0.875%
Line of Credit | Maximum
Debt Instrument [Line Items]
Variable rate		1.375%
Line of Credit | Term Loan
Debt Instrument [Line Items]
Principal amount		$ 250.0
Total borrowings outstanding		231.3	237.5
Repayment of debt		$ 6.3
Line of Credit | Term Loan | 3/31/22 through 3/31/25
Debt Instrument [Line Items]
Repayment terms		1.25
Line of Credit | Term Loan | 6/30/25 through 11/18/26
Debt Instrument [Line Items]
Repayment terms		2.5
Line of Credit | Revolving Facility
Debt Instrument [Line Items]
Total borrowings outstanding		$ 39.0	69.0
Line of credit facility, borrowing capacity		500.0
Line of Credit Facility, Capacity available for issuance of letters of credit		100.0
Letters of credit outstanding amount		13.4
Line of Credit | Revolving Facility | Subsequent Event
Debt Instrument [Line Items]
Repayment of debt	$ 39.0
Senior Notes | 3.200% Senior Note due 2024
Debt Instrument [Line Items]
Principal amount		400.0
Total borrowings outstanding		$ 400.0	400.0
Stated interest rate		3.20%
Senior Notes | 3.550% Senior Note due 2027
Debt Instrument [Line Items]
Principal amount		$ 400.0
Total borrowings outstanding		$ 400.0	400.0
Stated interest rate		3.55%
Senior Notes | 3.500% Senior Notes Due 2029
Debt Instrument [Line Items]
Principal amount		$ 400.0
Total borrowings outstanding		$ 400.0	400.0
Stated interest rate		3.50%
Senior Notes | 5.411% Senior Notes Due 2032
Debt Instrument [Line Items]
Total borrowings outstanding		$ 600.0	$ 600.0
Stated interest rate		5.411%