Contract Receivables (Details) (USD $)	1 Months Ended	6 Months Ended
Jul. 31, 2013	Jun. 30, 2013	Dec. 31, 2012
Contract Receivables [Abstract]
Maximum term of contract receivables (in months)		12 months
Components of contract receivables [Abstract]
Billed receivables		$ 10,003,000	$ 12,403,000
Recoverable costs and accrued profit not billed		10,815,000	11,315,000
Allowance for doubtful accounts		(40,000)	(2,000)
Total contract receivables, net		20,778,000	23,716,000
Unbilled Contract Receivables Billed during July 2013	$ 1,600,000
Contract Receivable [Member] \| Slovenske elektrarne, a.s. [Member]
Percentage of contract receivable by major customer [Abstract]
Percentage of contract receivables accounted by major customers (in hundredths)		15.80%	17.40%
Contract Receivable [Member] \| Shandong Nuclear Power Co. Ltd. [Member]
Percentage of contract receivable by major customer [Abstract]
Percentage of contract receivables accounted by major customers (in hundredths)		15.60%	13.80%

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Describes the maximum period under which the entity considered its contract receivables to be collected.

+ References

No definition available.

+ Details

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- Details

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- Definition

The portion of Unbilled Contract Receivables billed during the one month period subsequent to the report date.

+ References

No definition available.

+ Details

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- Definition

Amount billed to customers under long-term contracts or programs but not paid. Excludes amounts due that have been withheld because of retainage provisions in a contract.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 910

-SubTopic 310

-Section 50

-Paragraph 3

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-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.3(c))

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

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-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 3

-Subparagraph c

-Article 5

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- Definition

For an unclassified balance sheet, a valuation allowance for receivables due a company 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 4

-URI http://asc.fasb.org/extlink&oid=7512638&loc=d3e5074-111524

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-Subparagraph (SX 210.9-03.10)

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- Definition

Amounts due for billed services rendered or to be rendered, actions taken or to be taken, or a promise to refrain from taking certain actions in accordance with the terms of a legally binding agreement between the Company and, at a minimum, one other party. An example would be amounts billed to customers under contracts or programs but not paid as of the balance sheet date.

+ References

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

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- Definition

For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

+ References

No definition available.

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- Definition

Unbilled amounts due for services rendered or to be rendered, actions taken or to be taken, or a promise to refrain from taking certain actions in accordance with the terms of a legally binding agreement between the entity and, at a minimum, one other party. An example would be amounts associated with contracts or programs where the recognized revenue for performance thereunder exceeds the amounts billed under the terms thereof as of the date of the balance sheet.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.3(c)(3))

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

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-Publisher FASB

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-Publisher AICPA

-Name Accounting Research Bulletin (ARB)

-Number 43

-Section A

-Paragraph 4, 21

-Chapter 11

-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.

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