Segment Information - Condensed Operating Data for Segments (Detail) (USD $)	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Segment Reporting Information [Line Items]
Subscription revenue	$ 9,946,045	$ 8,234,328
Cost of sales of subscription revenue	1,916,345	1,681,404
Gross profit	8,029,700	6,552,924
Operating expenses:
Sales and marketing	2,552,020	1,968,966
Product development	763,103	721,566
General and administrative expenses	3,037,442	3,169,311
Total operating expenses	6,352,565	5,859,843
Other income (expenses):
Interest and other income	3,058	2,198
Interest expense	(28,213)	(28,213)
Total other income (expenses)	(25,155)	(26,015)
Income (loss) before income taxes and discontinued operations	1,651,980	667,066
(Loss) from discontinued operations, before income taxes	(613,000)	(251,000)
Reis Services [Member]
Segment Reporting Information [Line Items]
Subscription revenue	9,946,000	8,234,000
Cost of sales of subscription revenue	1,916,000	1,681,000
Gross profit	8,030,000	6,553,000
Operating expenses:
Sales and marketing	2,552,000	1,969,000
Product development	763,000	722,000
General and administrative expenses	1,892,000	1,796,000
Total operating expenses	5,207,000	4,487,000
Other income (expenses):
Interest and other income	3,000	2,000
Interest expense	(28,000)	(28,000)
Total other income (expenses)	(25,000)	(26,000)
Income (loss) before income taxes and discontinued operations	2,798,000	2,040,000
(Loss) from discontinued operations, before income taxes
Other [Member]
Segment Reporting Information [Line Items]
Subscription revenue
Cost of sales of subscription revenue
Gross profit
Operating expenses:
Sales and marketing
Product development
General and administrative expenses	1,146,000	1,373,000
Total operating expenses	1,146,000	1,373,000
Other income (expenses):
Interest and other income
Interest expense
Total other income (expenses)
Income (loss) before income taxes and discontinued operations	(1,146,000)	(1,373,000)
(Loss) from discontinued operations, before income taxes	(585,000)	(251,000)
Discontinued Operations [Member]
Segment Reporting Information [Line Items]
Subscription revenue
Cost of sales of subscription revenue
Gross profit
Operating expenses:
Sales and marketing
Product development
General and administrative expenses
Total operating expenses
Other income (expenses):
Interest and other income
Interest expense
Total other income (expenses)
Income (loss) before income taxes and discontinued operations
(Loss) from discontinued operations, before income taxes	$ (28,000)