Organization, Consolidation and Summary of Significant Accounting Policies - Additional Information (Detail) (USD $)	3 Months Ended		12 Months Ended			36 Months Ended
	Sep. 30, 2011	Sep. 30, 2008	Dec. 31, 2012 Segment	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2012
Organization, Consolidation And Summary Of Significant Accounting Policies [Line Items]
Percentage of revenue accounted for by top 5 customers			12.00%	15.00%	10.00%
Other-Than-Temporary Investment Charge		$ 3,500,000
Investment of auction rate securities, carrying value		0
Percentage of original investment recovered from sale of auction rate securities	72.00%
Recovery of previously impaired investment	2,519,000			2,519,000
Redemption of auction rate securities						3,000,000
Cash balance			50,800,000			50,800,000
Cash equivalents			45,900,000			45,900,000
Short-term investments			6,310,000	6,079,000		6,310,000
Foreign exchange rate gains (losses)			(100,000)	800,000	(700,000)
Expense reimbursement recorded to revenue			12,600,000	10,400,000	9,000,000
Allowance for doubtful accounts recorded to operations			4,300,000	2,500,000	3,500,000
Depreciation and amortization expense			5,600,000	6,100,000	6,900,000
Goodwill			62,265,000	62,261,000		62,265,000
Gross goodwill deductible for income tax purposes			36,000,000	36,000,000		36,000,000
Customer's license amortization period			5 years
Number of reporting segments			3
Advertising costs			95,000	240,000	10,000
Options to purchase shares of common stock outstanding that were not included in the computation of diluted earnings per share				2,000	1,312,639
Computer Software | Minimum
Organization, Consolidation And Summary Of Significant Accounting Policies [Line Items]
Property and equipment estimated useful life			3 years
Computer Software | Maximum
Organization, Consolidation And Summary Of Significant Accounting Policies [Line Items]
Property and equipment estimated useful life			5 years
Office Equipment
Organization, Consolidation And Summary Of Significant Accounting Policies [Line Items]
Property and equipment estimated useful life			5 years
Furniture and Fixtures
Organization, Consolidation And Summary Of Significant Accounting Policies [Line Items]
Property and equipment estimated useful life			7 years
Leasehold Improvements
Organization, Consolidation And Summary Of Significant Accounting Policies [Line Items]
Leasehold improvements useful life			Lesser of their useful lives or the term of the lease.
Money Market Funds
Organization, Consolidation And Summary Of Significant Accounting Policies [Line Items]
Available-for-sale securities			35,200,000			35,200,000
Americas
Organization, Consolidation And Summary Of Significant Accounting Policies [Line Items]
Accounts receivable, net			51,000,000	46,000,000		51,000,000
Recovery of previously impaired investment				2,519,000
Goodwill			54,766,000	54,766,000		54,766,000
EMEA
Organization, Consolidation And Summary Of Significant Accounting Policies [Line Items]
Accounts receivable, net			8,200,000	6,100,000		8,200,000
Goodwill			5,536,000	5,532,000		5,536,000
APAC
Organization, Consolidation And Summary Of Significant Accounting Policies [Line Items]
Accounts receivable, net			2,800,000	4,100,000		2,800,000
Goodwill			$ 1,963,000	$ 1,963,000		$ 1,963,000