Financial Instruments (Fair Value of Assets and Liabilities) (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Liabilities:
Other derivative liabilities	$ 50.7	$ 103.0
Contingent consideration - other accrued liabilities and other long-term liabilities	64.4	67.3
Fair Value, Measurements, Recurring
Assets:
Total assets	118.0	179.9
Liabilities:
Contingent consideration - other accrued liabilities and other long-term liabilities	68.8	70.6
Total liabilities	119.5	173.6
Fair Value, Measurements, Recurring | Quoted Prices in Active Markets (Level 1)
Assets:
Total assets	35.2	32.3
Liabilities:
Contingent consideration - other accrued liabilities and other long-term liabilities	0.0	0.0
Total liabilities	0.0	0.0
Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2)
Assets:
Total assets	82.8	147.6
Liabilities:
Contingent consideration - other accrued liabilities and other long-term liabilities	0.0	0.0
Total liabilities	50.7	103.0
Fair Value, Measurements, Recurring | Significant Unobservable Inputs (Level 3)
Assets:
Total assets	0.0	0.0
Liabilities:
Contingent consideration - other accrued liabilities and other long-term liabilities	68.8	70.6
Total liabilities	68.8	70.6
Fair Value, Measurements, Recurring | Interest rate swaps - other assets
Assets:
Derivative assets	4.7	10.0
Fair Value, Measurements, Recurring | Interest rate swaps - other assets | Quoted Prices in Active Markets (Level 1)
Assets:
Derivative assets	0.0	0.0
Fair Value, Measurements, Recurring | Interest rate swaps - other assets | Significant Other Observable Inputs (Level 2)
Assets:
Derivative assets	4.7	10.0
Fair Value, Measurements, Recurring | Interest rate swaps - other assets | Significant Unobservable Inputs (Level 3)
Assets:
Derivative assets	0.0	0.0
Fair Value, Measurements, Recurring | Interest rate locks
Assets:
Derivative assets		63.8
Liabilities:
Other derivative liabilities		103.0
Fair Value, Measurements, Recurring | Interest rate locks | Quoted Prices in Active Markets (Level 1)
Assets:
Derivative assets		0.0
Liabilities:
Other derivative liabilities		0.0
Fair Value, Measurements, Recurring | Interest rate locks | Significant Other Observable Inputs (Level 2)
Assets:
Derivative assets		63.8
Liabilities:
Other derivative liabilities		103.0
Fair Value, Measurements, Recurring | Interest rate locks | Significant Unobservable Inputs (Level 3)
Assets:
Derivative assets		0.0
Liabilities:
Other derivative liabilities		0.0
Fair Value, Measurements, Recurring | Other derivative assets - other assets
Assets:
Derivative assets	15.0
Fair Value, Measurements, Recurring | Other derivative assets - other assets | Quoted Prices in Active Markets (Level 1)
Assets:
Derivative assets	0.0
Fair Value, Measurements, Recurring | Other derivative assets - other assets | Significant Other Observable Inputs (Level 2)
Assets:
Derivative assets	15.0
Fair Value, Measurements, Recurring | Other derivative assets - other assets | Significant Unobservable Inputs (Level 3)
Assets:
Derivative assets	0.0
Fair Value, Measurements, Recurring | Other derivative liabilities - other long-term liabilities
Liabilities:
Other derivative liabilities	50.7
Fair Value, Measurements, Recurring | Other Derivatives | Quoted Prices in Active Markets (Level 1)
Liabilities:
Other derivative liabilities	0.0
Fair Value, Measurements, Recurring | Other Derivatives | Significant Other Observable Inputs (Level 2)
Liabilities:
Other derivative liabilities	50.7
Fair Value, Measurements, Recurring | Other Derivatives | Significant Unobservable Inputs (Level 3)
Liabilities:
Other derivative liabilities	0.0
Fair Value, Measurements, Recurring | Money market accounts
Assets:
Money market mutual funds	35.2	32.3
Fair Value, Measurements, Recurring | Money market accounts | Quoted Prices in Active Markets (Level 1)
Assets:
Money market mutual funds	35.2	32.3
Fair Value, Measurements, Recurring | Money market accounts | Significant Other Observable Inputs (Level 2)
Assets:
Money market mutual funds	0.0	0.0
Fair Value, Measurements, Recurring | Money market accounts | Significant Unobservable Inputs (Level 3)
Assets:
Money market mutual funds	0.0	0.0
Fair Value, Measurements, Recurring | Bonds
Assets:
Bonds - restricted cash and marketable securities and other assets	63.1	73.8
Fair Value, Measurements, Recurring | Bonds | Quoted Prices in Active Markets (Level 1)
Assets:
Bonds - restricted cash and marketable securities and other assets	0.0	0.0
Fair Value, Measurements, Recurring | Bonds | Significant Other Observable Inputs (Level 2)
Assets:
Bonds - restricted cash and marketable securities and other assets	63.1	73.8
Fair Value, Measurements, Recurring | Bonds | Significant Unobservable Inputs (Level 3)
Assets:
Bonds - restricted cash and marketable securities and other assets	0.0	0.0
Carrying Amount
Assets:
Total assets	118.0	179.9
Liabilities:
Contingent consideration - other accrued liabilities and other long-term liabilities	68.8	70.6
Total liabilities	119.5	173.6
Carrying Amount | Interest rate swaps - other assets
Assets:
Derivative assets	4.7	10.0
Carrying Amount | Interest rate locks
Assets:
Derivative assets		63.8
Liabilities:
Other derivative liabilities		103.0
Carrying Amount | Other derivative assets - other assets
Assets:
Derivative assets	15.0
Carrying Amount | Other derivative liabilities - other long-term liabilities
Liabilities:
Other derivative liabilities	50.7
Carrying Amount | Money market accounts
Assets:
Money market mutual funds	35.2	32.3
Carrying Amount | Bonds
Assets:
Bonds - restricted cash and marketable securities and other assets	$ 63.1	$ 73.8