Segment Information - Additional Information (Detail)					2 Months Ended	12 Months Ended			39 Months Ended
	Oct. 15, 2012 USD ($)	Aug. 03, 2012 USD ($)	Jun. 20, 2012 USD ($)	Mar. 13, 2012 USD ($)	Feb. 24, 2017 USD ($)	Dec. 31, 2016 USD ($) Subscriber	Dec. 31, 2015 USD ($) Subscriber	Dec. 31, 2014 USD ($)	Dec. 31, 2015 USD ($) Subscriber	Sep. 30, 2009 a Segment
Segment Reporting Information [Line Items]
Litigation recoveries							$ 4,839,000	$ 26,000	$ 5,658,000
Gold Peak [Member]
Segment Reporting Information [Line Items]
Number of units prior to sale | Segment										259
Number of acres prior to sale | a										29
Litigation charge regarding construction defects				$ 18,200,000
Other charges regarding construction defects				$ 756,000
Settlement with the plaintiff			$ 17,000,000
Gold Peak [Member] | First Installment [Member]
Segment Reporting Information [Line Items]
Installment amount due		$ 5,000,000
Installment due date						Aug. 03, 2012
Gold Peak [Member] | Second Installment [Member]
Segment Reporting Information [Line Items]
Installment amount due	$ 12,000,000
Installment due date						Oct. 15, 2012
Reis Services [Member]
Segment Reporting Information [Line Items]
Percentage of Reis Service's revenue by major subscriber						6.30%	10.60%	2.90%
Major customer custom revenue						$ 1,200,000	$ 4,519,000
Number of subscribers contributing largest share among accounts receivable | Subscriber						23	23		23
Aggregate percentage of subscribers contributing largest share among accounts receivable						52.40%	63.90%		63.90%
Number of subscribers contributing largest share among major accounts receivable | Subscriber						2	4		4
Percentage of accounts receivable accounted for by major subscribers						4.00%	4.00%		4.00%
Percentage of Reis Service's accounts receivable by major subscriber						8.30%	17.40%		17.40%
Aggregate accounts receivable by major subscriber							$ 2,400,000
Percentage of deferred revenue by major subscriber						3.70%	6.80%		6.80%
Reis Services [Member] | Subsequent Event [Member]
Segment Reporting Information [Line Items]
Payments received against accounts receivable					$ 5,000,000
Percentage collected from trade accounts receivable					50.00%