Note 6 - Acquisitions (Details Textual) - USD ($) $ in Millions			3 Months Ended		9 Months Ended
		Sep. 09, 2020	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Escrow Deposit			$ 16.8		$ 16.8		$ 10.5
Goodwill, Ending Balance			3,924.9		3,924.9		3,864.3
Current Portion of Escrow			1.7		1.7		0.5
Payment for Contingent Consideration Liability, Financing Activities			(0.0)	$ (0.0)	34.2	$ (0.0)
Franco Signor [Member]
Business Acquisition, Percentage of Voting Interests Acquired		100.00%
Business Combination, Consideration Transferred, Total		$ 159.9
Escrow Deposit		8.0
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Restricted Cash	[1]	5.7
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Offsetting Liability Included Within Current Liabilities		5.7
Goodwill, Ending Balance		99.9
Business Acquisition, Goodwill Non-tax Deductible, Amount		$ 22.8
Business Combination, Acquisition Related Costs			0.5		0.5
The 2019 Acquisitions [Member]
Business Combination, Acquisition Related Costs				$ 0.3		$ 1.6
Healix International Holdings Limited and Rebmark Legal Solutions Limited [Member]
Business Combination, Contingent Consideration, Liability, Current			12.6		12.6		111.2
Payment for Contingent Consideration Liability, Financing Activities					98.6
Business Combination, Acquisition Related Liability, Current			$ 0.2		$ 0.2		$ 0.2

[1] Within cash and cash equivalents, there is $5.7 million of restricted cash related to Franco Signor's professional administrative services for Medicare Set Asides, with an offsetting liability of $5.7 million included within current liabilities.