Capitalized Data and Database Development Costs, Net (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Research And Development [Line Items]
Capitalized data and database costs gross	$ 518,917,000	$ 486,019,000
Less accumulated amortization	(188,729,000)	(163,730,000)
Capitalized data and database costs, net	330,188,000	322,289,000
Amortization	30,100,000	27,300,000	23,200,000
Property Data [Member]
Research And Development [Line Items]
Capitalized data and database costs gross	446,941,000	417,516,000
Flood [Member]
Research And Development [Line Items]
Capitalized data and database costs gross	55,416,000	52,916,000
Eviction Data [Member]
Research And Development [Line Items]
Capitalized data and database costs gross	$ 16,560,000	$ 15,587,000