Website Development Costs and Computer Software Developed for Internal Use - Additional Information (Detail) (USD $)	3 Months Ended
Mar. 31, 2014	Mar. 31, 2013
Property Plant And Equipment [Abstract]
Capitalized website development costs	$ 565,000	$ 502,000
Amortization of capitalized website costs	$ 607,000	$ 606,000

For each income statement presented, the amount charged to expense for amortization of capitalized computer software costs.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 985

-SubTopic 20

-Section 50

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6501960&loc=d3e128487-111756

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 985

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=6501960&loc=d3e128462-111756

Name:	us-gaap_CapitalizedComputerSoftwareAmortization
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration