Business Combinations - Purchase Price Allocation for Current Year Acquisitions and Adjustments Made for Prior Year Acquisitions (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
	Mar. 31, 2021	Jun. 30, 2022
Business Combination Separately Recognized Transactions [Line Items]
Cash paid		$ 500.9
Common stock issued	$ 4.9	0.0
Other payable		1.2
Recorded earn-out payable		16.9
Net assets acquired		519.0
Orchid Intermediate Holdings L P
Business Combination Separately Recognized Transactions [Line Items]
Net assets acquired		$ 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
Maximum potential earn- out payable		20.0
Other Acquisitions
Business Combination Separately Recognized Transactions [Line Items]
Net assets acquired		32.0
Other Acquisitions | Various
Business Combination Separately Recognized Transactions [Line Items]
Cash paid		24.7
Common stock issued		0.0
Other payable		1.2
Recorded earn-out payable		6.1
Net assets acquired		32.0
Maximum potential earn- out payable		8.8
2022 Acquisition
Business Combination Separately Recognized Transactions [Line Items]
Maximum potential earn- out payable		$ 28.8