Business Combinations - Purchase Price Allocation for Current Year Acquisitions and Adjustments Made for Prior Year Acquisitions (Details) - USD ($) $ in Millions		3 Months Ended
	Mar. 31, 2022	Mar. 31, 2022	Mar. 31, 2021
Business Combination Separately Recognized Transactions [Line Items]
Cash paid		$ 479.7
Common stock issued		0.0	$ 4.9
Other payable		0.0
Recorded earn-out payable		10.8
Net assets acquired	$ 490.5	490.5
Orchid Intermediate Holdings, L.P.
Business Combination Separately Recognized Transactions [Line Items]
Net assets acquired	$ 487.0	487.0
Orchid Intermediate Holdings, L.P. | National Programs
Business Combination Separately Recognized Transactions [Line Items]
Effective date of acquisition	Mar. 31, 2022
Cash paid	$ 476.2
Common stock issued	0.0
Other payable	0.0
Recorded earn-out payable	10.8
Net assets acquired	487.0	487.0
Maximum potential earn- out payable	20.0	20.0
Other Acquisitions
Business Combination Separately Recognized Transactions [Line Items]
Net assets acquired	3.5	3.5
Other Acquisitions | Various
Business Combination Separately Recognized Transactions [Line Items]
Cash paid		3.5
Common stock issued		0.0
Other payable		0.0
Recorded earn-out payable		0.0
Net assets acquired	3.5	3.5
Maximum potential earn- out payable	0.0	0.0
2022 Acquisition
Business Combination Separately Recognized Transactions [Line Items]
Maximum potential earn- out payable	$ 20.0	$ 20.0