Capitalized Software Costs (Details) (USD $) In Thousands	Sep. 30, 2011	Mar. 31, 2011	Sep. 30, 2010	Mar. 31, 2010
Capitalized software development costs
Gross carrying amount	$ 58,256	$ 52,123
Accumulated amortization	(40,861)	(36,973)
Net capitalized software costs	$ 17,395	$ 15,150	$ 13,799	$ 11,546

For each balance sheet presented, the amount of accumulated amortization for capitalized computer software costs.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Implementation Guide (Q and A)

-Number FAS86

-Paragraph 21

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 142

-Paragraph 45

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 985

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=6501960&loc=d3e128462-111756

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 30

-Section 50

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-URI http://asc.fasb.org/extlink&oid=6905858&loc=d3e16323-109275

Name:	us-gaap_CapitalizedComputerSoftwareAccumulatedAmortization
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant