Geographic Information (Details) (USD $) In Thousands	3 Months Ended
Jun. 30, 2011	Jun. 30, 2010
Total revenue	$ 63,296	$ 66,811
United States [Member]
Total revenue	46,240	53,060
Europe [Member]
Total revenue	7,601	6,255
Asia [Member]
Total revenue	4,258	2,823
Rest Of The World [Member]
Total revenue	$ 5,197	$ 4,673

Aggregate revenue recognized during the period (derived from goods sold, services rendered, insurance premiums, or other activities that constitute an entity's earning process). For financial services companies, also includes investment and interest income, and sales and trading gains.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Article 5
-Section 03
-Paragraph 1

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.1)
-URI http://asc.fasb.org/extlink&oid=6880815&loc=d3e20235-122688

Name:	us-gaap_Revenues
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration