Financing Receivables (Details) (USD $)	6 Months Ended
Sep. 30, 2011	Mar. 31, 2011
Financing Receivables [Abstract]
Minimum finance receivable deferred payment term (in years)	1Y
Annual interest rate on loan receivable (in hundredths)	7.00%
Interest payment received on loan receivable	$ 2,400,000
Loan receivable	5,600,000
Financing Receivable, Recorded Investment, Past Due [Line Items]
0-29 days past invoice date	2,724,000	6,439,000
30-90 days past invoice date	941,000	503,000
Greater than 90 days past invoice date	163,000	219,000
Unbilled	44,766,000	48,004,000
Receivables	48,594,000	55,165,000
Allowance for credit losses on financing receivables	327,000	389,000
Pass Rating [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
0-29 days past invoice date	2,724,000	6,439,000
30-90 days past invoice date	941,000	434,000
Greater than 90 days past invoice date	26,000	179,000
Unbilled	44,576,000	47,724,000
Receivables	48,267,000	54,776,000
Pass Rating [Member] \| Software products [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
0-29 days past invoice date	2,724,000	6,439,000
30-90 days past invoice date	941,000	434,000
Greater than 90 days past invoice date	26,000	179,000
Unbilled	44,576,000	37,971,000
Receivables	48,267,000	45,023,000
Pass Rating [Member] \| Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Unbilled	6,378,000	9,753,000
Receivables	6,378,000	9,753,000
Watch Rating [Member] \| Software products [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
0-29 days past invoice date	0	0
30-90 days past invoice date	0	69,000
Greater than 90 days past invoice date	137,000	40,000
Unbilled	190,000	280,000
Receivables	$ 327,000	$ 389,000

The annual interest rate on the ForeSee note receivable under the new payment terms.

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Namespace Prefix:	cpwr
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Balance Type:	na
Period Type:	instant

- Definition

Financing receivables that are either current or less than 30 days past invoice due.

+ Details

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Namespace Prefix:	cpwr
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Financing receivables that are less than 91 days past invoice date but more than 29 days past invoice date.

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Financing receivables that are greater than 90 days past invoice date.

+ Details

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Namespace Prefix:	cpwr
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Minimum finance receivable deferred payment term.

+ Details

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Data Type:	us-types:durationStringItemType
Balance Type:	na
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- Definition

The amount of the recorded investment in a contractual right to receive money on demand or on fixed or determinable dates that is recognized as an asset in the creditor's statement of financial position. Examples include, but are not limited to, accounts receivable (with terms exceeding one year), notes receivable and receivables relating to lessor's rights to payments from leases other than operating leases that have been recorded as assets.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Financing Receivable

-URI http://asc.fasb.org/extlink&oid=6953735

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

A valuation allowance for financing receivables that are expected to be uncollectible.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 50

-Paragraph 11B

-URI http://asc.fasb.org/extlink&oid=6965416&loc=SL6953423-111524

-Subparagraph (c)(1)

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ Details

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- Definition

An amount representing an agreement for an unconditional promise by the maker to pay the Entity (holder) a definite sum of money at a future date(s) more than one year from the balance sheet date. Such amount may include accrued interest receivable in accordance with the terms of the debt. The debt also may contain provisions and related items including a discount or premium, payable on demand, secured, or unsecured, interest bearing or noninterest bearing, among a myriad of other features and characteristics. This amount does not include amounts related to receivables held-for-sale.

+ References

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 17

-Article 5

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.17)

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

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Balance Type:	debit
Period Type:	instant

- Definition

Interest received on loans and other debt instruments during the current period.

+ References

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 95

-Paragraph 27

-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 Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 25

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=6943989&loc=d3e3536-108585

+ Details

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- Details

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- Definition

The total amount of unbilled receivables from customers under long-term contracts that have not been billed and were not billable at the balance sheet date.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 910

-SubTopic 310

-Section 50

-Paragraph 2

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=6471494&loc=d3e49336-109356

+ Details

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Balance Type:	debit
Period Type:	instant