Note 6 - Acquisitions - Assets Acquired and Liabilities Assumed (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021
Goodwill	$ 3,820.4		$ 3,820.4		$ 4,331.2
Less: Cash acquired	17.4	$ 1.9	17.4	$ 5.7
Net cash purchase price	3.5	$ 17.8	448.9	$ 31.5
Opta Information Intelligence Corp. [Member]
Cash and cash equivalents	0.4		0.4
Accounts receivable	5.2		5.2
Other current assets	1.3		1.3
Fixed assets	1.5		1.5
Operating lease right-of-use assets, net	1.0		1.0
Intangible assets	83.4		83.4
Goodwill	146.4		146.4
Other noncurrent assets	0.1		0.1
Total assets acquired	239.3		239.3
Accounts payable and accrued liabilities	4.2		4.2
Deferred revenues	0.2		0.2
Operating lease liabilities	1.1		1.1
Deferred income tax, net	15.9		15.9
Other noncurrent liabilities	0.0		0.0
Total liabilities assumed	21.4		21.4
Net assets acquired	217.9		217.9
Less: Cash acquired			0.4
Net cash purchase price			217.5
Infutor Data Solutions, LLC [Member]
Cash and cash equivalents	17.0		17.0
Accounts receivable	10.7		10.7
Other current assets	3.8		3.8
Fixed assets	0.9		0.9
Operating lease right-of-use assets, net	2.3		2.3
Intangible assets	83.4		83.4
Goodwill	140.4		140.4
Other noncurrent assets	0.1		0.1
Total assets acquired	258.6		258.6
Accounts payable and accrued liabilities	14.5		14.5
Deferred revenues	3.1		3.1
Operating lease liabilities	3.3		3.3
Deferred income tax, net	0.0		0.0
Other noncurrent liabilities	0.0		0.0
Total liabilities assumed	20.9		20.9
Net assets acquired	237.7		237.7
Less: Cash acquired			17.0
Net cash purchase price			220.7
Acquisition, Others [Member]
Cash and cash equivalents	0.0		0.0
Accounts receivable	0.0		0.0
Other current assets	0.1		0.1
Fixed assets	0.3		0.3
Operating lease right-of-use assets, net	0.0		0.0
Intangible assets	2.3		2.3
Goodwill	3.0		3.0
Other noncurrent assets	0.0		0.0
Total assets acquired	5.7		5.7
Accounts payable and accrued liabilities	0.1		0.1
Deferred revenues	0.1		0.1
Operating lease liabilities	0.0		0.0
Deferred income tax, net	0.6		0.6
Other noncurrent liabilities	0.1		0.1
Total liabilities assumed	0.9		0.9
Net assets acquired	4.8		4.8
Less: Cash acquired			0.0
Net cash purchase price			4.8
2022 Acquisition [Member]
Cash and cash equivalents	17.4		17.4
Accounts receivable	15.9		15.9
Other current assets	5.2		5.2
Fixed assets	2.7		2.7
Operating lease right-of-use assets, net	3.3		3.3
Intangible assets	169.1		169.1
Goodwill	289.8		289.8
Other noncurrent assets	0.2		0.2
Total assets acquired	503.6		503.6
Accounts payable and accrued liabilities	18.8		18.8
Deferred revenues	3.4		3.4
Operating lease liabilities	4.4		4.4
Deferred income tax, net	16.5		16.5
Other noncurrent liabilities	0.1		0.1
Total liabilities assumed	43.2		43.2
Net assets acquired	$ 460.4		460.4
Less: Cash acquired			17.4
Net cash purchase price			$ 443.0