Operating Revenues - Operating Revenues by Solution Type (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Disaggregation of Revenue [Line Items]
Operating revenues	$ 436,727	$ 375,571	$ 1,174,733	$ 1,088,032
Property insights
Disaggregation of Revenue [Line Items]
Operating revenues	126,325	120,340	359,175	359,278
Insurance and spatial solutions
Disaggregation of Revenue [Line Items]
Operating revenues	49,923	48,739	145,204	142,576
Flood data solutions
Disaggregation of Revenue [Line Items]
Operating revenues	34,351	22,983	91,931	61,572
Valuation solutions
Disaggregation of Revenue [Line Items]
Operating revenues	58,434	77,426	182,637	230,891
Property tax solutions
Disaggregation of Revenue [Line Items]
Operating revenues	166,858	103,671	$ 394,799	282,724
Expected service period revenue is recognized			10 years
Other
Disaggregation of Revenue [Line Items]
Operating revenues	836	2,412	$ 987	10,991
Operating Segments | PIRM
Disaggregation of Revenue [Line Items]
Operating revenues	176,248	169,079	504,379	501,854
Operating Segments | PIRM | Property insights
Disaggregation of Revenue [Line Items]
Operating revenues	126,325	120,340	359,175	359,278
Operating Segments | PIRM | Insurance and spatial solutions
Disaggregation of Revenue [Line Items]
Operating revenues	49,923	48,739	145,204	142,576
Operating Segments | PIRM | Flood data solutions
Disaggregation of Revenue [Line Items]
Operating revenues	0	0	0	0
Operating Segments | PIRM | Valuation solutions
Disaggregation of Revenue [Line Items]
Operating revenues	0	0	0	0
Operating Segments | PIRM | Property tax solutions
Disaggregation of Revenue [Line Items]
Operating revenues	0	0	0	0
Operating Segments | PIRM | Other
Disaggregation of Revenue [Line Items]
Operating revenues	0	0	0	0
Operating Segments | UWS
Disaggregation of Revenue [Line Items]
Operating revenues	263,342	209,138	680,455	593,175
Operating Segments | UWS | Property insights
Disaggregation of Revenue [Line Items]
Operating revenues	0	0	0	0
Operating Segments | UWS | Insurance and spatial solutions
Disaggregation of Revenue [Line Items]
Operating revenues	0	0	0	0
Operating Segments | UWS | Flood data solutions
Disaggregation of Revenue [Line Items]
Operating revenues	34,351	22,983	91,931	61,572
Operating Segments | UWS | Valuation solutions
Disaggregation of Revenue [Line Items]
Operating revenues	58,434	77,426	182,637	230,891
Operating Segments | UWS | Property tax solutions
Disaggregation of Revenue [Line Items]
Operating revenues	166,858	103,671	394,799	282,724
Operating Segments | UWS | Other
Disaggregation of Revenue [Line Items]
Operating revenues	3,699	5,058	11,088	17,988
Corporate and Eliminations
Disaggregation of Revenue [Line Items]
Operating revenues	(2,863)	(2,646)	(10,101)	(6,997)
Corporate and Eliminations | Property insights
Disaggregation of Revenue [Line Items]
Operating revenues	0	0	0	0
Corporate and Eliminations | Insurance and spatial solutions
Disaggregation of Revenue [Line Items]
Operating revenues	0	0	0	0
Corporate and Eliminations | Flood data solutions
Disaggregation of Revenue [Line Items]
Operating revenues	0	0	0	0
Corporate and Eliminations | Valuation solutions
Disaggregation of Revenue [Line Items]
Operating revenues	0	0	0	0
Corporate and Eliminations | Property tax solutions
Disaggregation of Revenue [Line Items]
Operating revenues	0	0	0	0
Corporate and Eliminations | Other
Disaggregation of Revenue [Line Items]
Operating revenues	$ (2,863)	$ (2,646)	$ (10,101)	$ (6,997)