Income Taxes - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Current:
U.S. federal	$ 4,755,000	$ 485,000	$ 1,081,000
Foreign	87,000	116,000	62,000
State and local	1,301,000	1,077,000	536,000
Total current	6,143,000	1,678,000	1,679,000
Deferred:
U.S. federal	(445,000)	2,430,000	941,000
Foreign	0	0	33,000
State and local	(40,000)	(83,000)	205,000
Total deferred	(485,000)	2,347,000	1,179,000
Provision for income taxes	5,658,000	4,025,000	2,858,000
Income taxes at federal statutory rate	4,980,000	3,506,000	2,279,000
State income taxes, net of federal benefit	793,000	656,000	482,000
Domestic production activities deduction	(236,000)	(151,000)	0
Nondeductible expenses	122,000	158,000	89,000
Foreign rate differential	(44,000)	(45,000)	(33,000)
Other	43,000	(99,000)	41,000
Deferred tax assets:
Net operating loss and tax credit carryforwards	17,627,000	18,445,000
Stock-based compensation	2,265,000	2,218,000
Accrued expenses	201,000	201,000
Allowance for doubtful accounts and other reserves	832,000	882,000
Deferred rent	2,903,000	406,000
Other	363,000	341,000
Total deferred tax assets	24,191,000	22,493,000
Deferred tax liabilities:
Intangible assets	(2,113,000)	(2,397,000)
Property and equipment	(374,000)	(784,000)
Capitalized software costs, net of amortization	(304,000)	(268,000)
Total deferred tax liabilities	(2,791,000)	(3,449,000)
Net deferred tax assets	21,400,000	19,044,000
Valuation allowance	0	0
Total net deferred tax assets	21,400,000	19,044,000
Current deferred tax assets	2,900,000	3,000,000
Non-current deferred tax assets	21,200,000	19,500,000
Non-current deferred tax liabilities	2,800,000	3,400,000
Net operating loss carryforwards	57,100,000
Net operating loss carryforwards future taxable income offset limitation	3,600,000
Unrecognized tax benefits related to net operating loss	4,200,000
Unrecognized Tax Benefits Resulting in Net Operating Loss Carryforward Recorded in Other Long-tern Liabilities	3,100,000
Tax benefit attributable to all recorded stock-based compensation	48,000	970,000
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Balances of unrecognized tax benefits as of January 1	4,403,000	4,403,000
Increases for positions taken in prior years	0	0
Increases for positions related to the current year	0	0
Amounts of decreases related to the settlements	0	0
Reductions due to lapse of statutes of limitations	0	0
Balance of unrecognized tax benefits as of December 31	4,403,000	4,403,000	4,403,000
Unrecognized tax benefits	$ 4,403,000	$ 4,403,000	$ 4,403,000