Acquisitions - Allocation of Purchase Price (Detail) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012	Jan. 13, 2012 CardStar [Member]	Mar. 31, 2013 SinglePlatform [Member]	Dec. 31, 2012 SinglePlatform [Member]	Jun. 12, 2012 SinglePlatform [Member]
Purchase consideration:
Total cash paid, net of cash acquired						$ 62,546
Cash acquired						311
Fair value of contingent consideration	0	0		0	0	12,152
Total purchase price consideration						75,009
Assets acquired and liabilities assumed:
Cash						311
Accounts receivable						48
Prepaid expenses and other current assets						60
Property and equipment						14
Purchased technology and Identifiable intangible assets			624			4,760
Other assets						91
Net deferred tax assets			553			72
Goodwill			4,573			71,997
Total assets acquired			5,750			77,353
Accounts payable, accrued expenses and other current liabilities						(1,734)
Deferred revenue						(610)
Total liabilities assumed						(2,344)
Total allocation of purchase price consideration						$ 75,009