Segment Information - Condensed Balance Sheet Data for Segment (Detail) (USD $)	Mar. 31, 2014	Dec. 31, 2013	Mar. 31, 2013	Dec. 31, 2012
Current assets:
Cash and cash equivalents	$ 15,787,761	$ 10,559,899	$ 6,658,903	$ 4,960,850
Restricted cash and investments	216,835	216,702
Accounts receivable, net	5,124,171	11,386,584
Prepaid and other assets	2,173,767	2,787,909
Assets attributable to discontinued operations	3,500	8,500
Total current assets	23,306,034	24,959,594
Furniture, fixtures and equipment, net	864,761	853,377
Intangible assets, net	15,612,310	15,687,117
Deferred tax asset, net	21,586,520	21,316,520
Goodwill	54,824,648	54,824,648
Other assets	204,095	225,528
Total assets	116,398,368	117,866,784
Current liabilities:
Current portion of debt
Accrued expenses and other liabilities	1,991,795	3,578,227
Liability for option cancellations	123,713	268,341
Deferred revenue	19,251,022	20,284,178
Liabilities attributable to discontinued operations	507,352	342,138
Total current liabilities	21,873,882	24,472,884
Other long-term liabilities	536,456	522,941
Deferred tax liability, net
Total liabilities	22,410,338	24,995,825
Total stockholders' equity	93,988,030	92,870,959
Total liabilities and stockholders' equity	116,398,368	117,866,784
Reis Services [Member]
Current assets:
Cash and cash equivalents	15,629,000	10,347,000
Restricted cash and investments	217,000	217,000
Accounts receivable, net	5,124,000	11,386,000
Prepaid and other assets	208,000	187,000
Assets attributable to discontinued operations
Total current assets	21,178,000	22,137,000
Furniture, fixtures and equipment, net	842,000	829,000
Intangible assets, net	15,612,000	15,687,000
Deferred tax asset, net	285,000	285,000
Goodwill	57,203,000	57,203,000
Other assets	204,000	225,000
Total assets	95,324,000	96,366,000
Current liabilities:
Current portion of debt
Accrued expenses and other liabilities	1,430,000	2,623,000
Liability for option cancellations
Deferred revenue	19,251,000	20,284,000
Liabilities attributable to discontinued operations
Total current liabilities	20,681,000	22,907,000
Other long-term liabilities	536,000	523,000
Deferred tax liability, net	20,031,000	18,957,000
Total liabilities	41,248,000	42,387,000
Total stockholders' equity	54,076,000	53,979,000
Total liabilities and stockholders' equity	95,324,000	96,366,000
Other [Member]
Current assets:
Cash and cash equivalents	159,000	213,000
Restricted cash and investments
Accounts receivable, net
Prepaid and other assets	1,965,000	2,601,000
Assets attributable to discontinued operations	4,000	9,000
Total current assets	2,128,000	2,823,000
Furniture, fixtures and equipment, net	22,000	24,000
Intangible assets, net
Deferred tax asset, net	21,302,000	21,032,000
Goodwill	(2,378,000)	(2,378,000)
Other assets
Total assets	21,074,000	21,501,000
Current liabilities:
Current portion of debt
Accrued expenses and other liabilities	562,000	956,000
Liability for option cancellations	124,000	268,000
Deferred revenue
Liabilities attributable to discontinued operations	236,000	71,000
Total current liabilities	922,000	1,295,000
Other long-term liabilities
Deferred tax liability, net	(20,031,000)	(18,957,000)
Total liabilities	(19,109,000)	(17,662,000)
Total stockholders' equity	40,183,000	39,163,000
Total liabilities and stockholders' equity	21,074,000	21,501,000
Discontinued Operations [Member]
Current assets:
Cash and cash equivalents
Restricted cash and investments
Accounts receivable, net
Prepaid and other assets
Assets attributable to discontinued operations
Total current assets
Furniture, fixtures and equipment, net
Intangible assets, net
Deferred tax asset, net
Goodwill
Other assets
Total assets
Current liabilities:
Current portion of debt
Accrued expenses and other liabilities
Liability for option cancellations
Deferred revenue
Liabilities attributable to discontinued operations	271,000	271,000
Total current liabilities	271,000	271,000
Other long-term liabilities
Deferred tax liability, net
Total liabilities	271,000	271,000
Total stockholders' equity	(271,000)	(271,000)
Total liabilities and stockholders' equity