Acquisition (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012
Assets:
Cash	$ 85
Accounts receivable	561
Other current assets	285
Goodwill	3,695
Intangible assets	4,815
Total assets	9,441
Liabilities:
Accrued expenses	160
Deferred revenue	312
Total liabilities	472
Net assets acquired	$ 8,969