Segment Information - Condensed Operating Data for Segments (Detail) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Segment Reporting Information [Line Items]
Subscription revenue	$ 10,468,941	$ 8,780,212	$ 30,609,361	$ 25,512,849
Cost of sales of subscription revenue	2,072,977	1,755,020	5,963,564	5,111,217
Gross profit	8,395,964	7,025,192	24,645,797	20,401,632
Operating expenses:
Sales and marketing	2,573,236	2,096,965	7,666,463	6,097,549
Product development	945,444	835,811	2,522,572	2,349,576
General and administrative expenses	2,981,806	2,893,109	9,221,399	9,167,171
Total operating expenses	6,500,486	5,825,885	19,410,434	17,614,296
Other income (expenses):
Interest and other income	6,262	2,943	15,391	7,472
Interest expense	(28,352)	(28,352)	(84,848)	(84,848)
Total other income (expenses)	(22,090)	(25,409)	(69,457)	(77,376)
Income (loss) before income taxes and discontinued operations	1,873,388	1,173,898	5,165,906	2,709,960
(Loss) from discontinued operations, before income taxes	(84,000)	(92,000)	(872,000)	(405,000)
Reis Services [Member]
Segment Reporting Information [Line Items]
Subscription revenue	10,469,000	8,780,000	30,609,000	25,512,000
Cost of sales of subscription revenue	2,073,000	1,755,000	5,963,000	5,111,000
Gross profit	8,396,000	7,025,000	24,646,000	20,401,000
Operating expenses:
Sales and marketing	2,573,000	2,097,000	7,666,000	6,098,000
Product development	946,000	836,000	2,523,000	2,349,000
General and administrative expenses	1,931,000	1,686,000	5,902,000	5,205,000
Total operating expenses	5,450,000	4,619,000	16,091,000	13,652,000
Other income (expenses):
Interest and other income	6,000	3,000	15,000	7,000
Interest expense	(28,000)	(28,000)	(84,000)	(84,000)
Total other income (expenses)	(22,000)	(25,000)	(69,000)	(77,000)
Income (loss) before income taxes and discontinued operations	2,924,000	2,381,000	8,486,000	6,672,000
(Loss) from discontinued operations, before income taxes	0	0	0	0
Other [Member]
Segment Reporting Information [Line Items]
Subscription revenue	0	0	0	0
Cost of sales of subscription revenue	0	0	0	0
Gross profit	0	0	0	0
Operating expenses:
Sales and marketing	0	0	0	0
Product development	0	0	0	0
General and administrative expenses	1,051,000	1,207,000	3,320,000	3,962,000
Total operating expenses	1,051,000	1,207,000	3,320,000	3,962,000
Other income (expenses):
Interest and other income	0	0	0	0
Interest expense	0	0	0	0
Total other income (expenses)	0	0	0	0
Income (loss) before income taxes and discontinued operations	(1,051,000)	(1,207,000)	(3,320,000)	(3,962,000)
(Loss) from discontinued operations, before income taxes	(81,000)	(84,000)	(841,000)	(397,000)
Discontinued Operations [Member]
Segment Reporting Information [Line Items]
Subscription revenue	0	0	0	0
Cost of sales of subscription revenue	0	0	0	0
Gross profit	0	0	0	0
Operating expenses:
Sales and marketing	0	0	0	0
Product development	0	0	0	0
General and administrative expenses	0	0	0	0
Total operating expenses	0	0	0	0
Other income (expenses):
Interest and other income	0	0	0	0
Interest expense	0	0	0	0
Total other income (expenses)	0	0	0	0
Income (loss) before income taxes and discontinued operations	0	0	0	0
(Loss) from discontinued operations, before income taxes	$ (3,000)	$ (8,000)	$ (31,000)	$ (8,000)