Summary of Significant Accounting Policies - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Summary Of Significant Accounting Policies [Line Items]
Variable interest entity	$ 0	$ 0	$ 0
Maturity period of demand and money market accounts and short term investments	three months or less
Depreciation expense	333,000	355,000	352,000
Goodwill impairment identified	0	0	0
Intangible asset impairment	0	0	0
Impairment charges related to real estate assets			0
Fair value of assets	0	0	0
Fair value of liabilities	0	0	0
Company's share of the value of subscription	50.00%
Outstanding options	627,724	645,448	663,172	680,896
Settlement in cash or in stock	17,724	35,448	53,172
Liability for option cancellations	$ 268,341	$ 296,523
Minimum [Member]
Summary Of Significant Accounting Policies [Line Items]
Contractual period	1 year
Minimum [Member] | Furniture and Fixtures [Member]
Summary Of Significant Accounting Policies [Line Items]
Expected useful life of assets	3 years
Maximum [Member]
Summary Of Significant Accounting Policies [Line Items]
Contractual period	48 months
Maximum [Member] | Furniture and Fixtures [Member]
Summary Of Significant Accounting Policies [Line Items]
Expected useful life of assets	10 years
Web Site Development [Member]
Summary Of Significant Accounting Policies [Line Items]
Intangible assets, amortization period	3 years
Database [Member] | Minimum [Member]
Summary Of Significant Accounting Policies [Line Items]
Intangible assets, amortization period	3 years
Database [Member] | Maximum [Member]
Summary Of Significant Accounting Policies [Line Items]
Intangible assets, amortization period	5 years
Customer Relationships [Member]
Summary Of Significant Accounting Policies [Line Items]
Intangible assets, amortization period	15 years
Lease Value [Member]
Summary Of Significant Accounting Policies [Line Items]
Remaining term of acquired office lease	9 years