Note 7 - Goodwill and Other Acquired Intangible Assets, Net Accounting Policy Considerations (Details)	12 Months Ended
	Dec. 31, 2018 segment
Minimum | Client relationships
Acquired Finite-Lived Intangible Assets [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	5 years
Minimum | Technology
Acquired Finite-Lived Intangible Assets [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	3 years
Minimum | Trade names and trademarks
Acquired Finite-Lived Intangible Assets [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	6 years
Minimum | Licenses
Acquired Finite-Lived Intangible Assets [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	10 years
Minimum | Non-competition agreements
Acquired Finite-Lived Intangible Assets [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	2 years
Maximum | Client relationships
Acquired Finite-Lived Intangible Assets [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	15 years
Maximum | Technology
Acquired Finite-Lived Intangible Assets [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	8 years
Maximum | Trade names and trademarks
Acquired Finite-Lived Intangible Assets [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	10 years
Maximum | Non-competition agreements
Acquired Finite-Lived Intangible Assets [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	3 years
Mortgage and Real Estate Services Segment
Acquired Finite-Lived Intangible Assets [Line Items]
Number of Reporting Units	1