Net Revenues and Long Lived Assets by Geographic Area (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013		Mar. 31, 2012		Dec. 31, 2012
Segment Reporting Information [Line Items]
Net revenues	$ 189,106	[1]	$ 170,744	[1]
Long-lived assets	122,411	[2]			120,024	[2]
North America
Segment Reporting Information [Line Items]
Net revenues	173,287	[1],[3]	158,292	[1],[3]
Long-lived assets	1,765	[2],[3]			1,841	[2],[3]
India
Segment Reporting Information [Line Items]
Net revenues	355	[1]	355	[1]
Long-lived assets	120,572	[2]			118,095	[2]
Europe
Segment Reporting Information [Line Items]
Net revenues	13,976	[1],[4]	10,789	[1],[4]
Long-lived assets	74	[2],[4]			88	[2],[4]
Rest of the World
Segment Reporting Information [Line Items]
Net revenues	$ 1,488	[1]	$ 1,308	[1]

[1] Net revenues are attributed to regions based upon customer location.

[2] Long-lived assets include property and equipment, net of accumulated depreciation, amortization and goodwill.

[3] Primarily relates to operations in the United States.

[4] Primarily relates to operations in the United Kingdom.