Segments Schedule of revenue by geographic region (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Geographic Areas, Revenues from External Customers [Abstract]
Total revenue	$ 102,498	$ 100,957	$ 79,503
Geographic Areas, Long-Lived Assets [Abstract]
Property and equipment, net	5,365	3,631	2,701
Concentration Risks, Types, No Concentration Percentage [Abstract]
No. of revenue customers with 10% or greater concentration	0	0	0
No of Acct Rec customers with 10% or greater concentration	0	0
United States
Geographic Areas, Revenues from External Customers [Abstract]
Total revenue	91,763	90,108	73,719
Geographic Areas, Long-Lived Assets [Abstract]
Property and equipment, net	5,249	3,465	2,646
International
Geographic Areas, Revenues from External Customers [Abstract]
Total revenue	10,735	10,849	5,784
Geographic Areas, Long-Lived Assets [Abstract]
Property and equipment, net	$ 116	$ 166	$ 55